HEAT PROCESSING Gas- and plasmanitriding (Vorschau)

International Magazine for Industrial Furnaces
Heat Treatment & Equipment
01 I 2014
ISSN 1611-616X
Vulkan-Verlag
www.heatprocessing-online.com
The German Top Seminar:
Efficient
BURNER TECHNOLOGY
for Industrial Furnaces
31. March - 02. April 2014, Essen, ATLANTIC Congress Hotel
More Information and Online-Registration
www.gwi-brennertechnik.de
Induction solutions.
Hard to beat!
www.sms-elotherm.com

EDITORIAL
Specialized expertise and know-how
as a success factor
The products of our industry, i.e., thermal process engineering,
are often not standardized but consist of user-specific
solutions based on existing equipment such as burners, motors,
transformers, fans, switchgear and control systems, etc.
Consequently, a significant amount of engineering is involved
in planning, designing, functional testing and commissioning
each individual system. These activities require a high level of
specialized expertise.
At the same time it is worth noting that although modern
methods of numeric computing and simulation introduce an
increasing objectivity into the design, dimensioning and configuration
of equipment, there still remain plenty of blank areas
in which we depend mainly on experience. Let us just consider
the proper selection of the refractory lining of a melting furnace
for advanced metal alloys. Unfortunately, not everything can be
computed and simulated yet, or rather it is not economically
worthwhile to pursue this path for all components and tasks. No
doubt, technical progress will eventually help us to close this gap.
Moreover, without specialized expertise such calculations cannot
be effectively put to use – adopting them in an unreflected
manner might well lead to problems. In any case, their results
must be critically reviewed and verified, if appropriate, by testing.
Without a detailed understanding, even the tasks for such
calculations and simulations cannot be properly developed.
By analogy, we certainly possess very good work instructions
and assembly guidelines for the manufacture and installation of
our equipment, and these are being continuously expanded and
revised. Still, there exists valuable production know-how which
is difficult to transfer, for not everything can be written down
and documented so easily.
The equipment would not feature its high level of technological
refinement, reliability and safety if it were not for our
staff – people with high skills and many years of experience,
based on a deep grounding in science and technology. Again,
this applies equally to production and assembly processes, for
manual work and craftsmanship likewise demand extensive
experience when it comes to building flawless equipment for
use in industrial manufacturing.
On the other hand, key to further success will be our ability
to analyze accumulated findings and results gained with actually
built installations, and to put them to use for the purpose
of further optimization. This expressly includes a close cooperation,
in an open and friendly work spirit, between design and
manufacturing, installation and commissioning staff. There must
be no fear of contact, no reservations here. No helpful bit of
information must get lost – every input needs to be examined,
evaluated and implemented. Summing up: Skilled employees
are our most important asset – now as in the future.
Dr. Dietmar Trauzeddel
Otto Junker GmbH
1-2014 heat processing
1

TABLE OF CONTENTS 1-2014
6
HOT SHOTS
Seven-stand four-high finishing line in a hot strip mill
Reports
49
REPORTS
Energy efficiency in heat treatment shops
Ar1 max. temperature 320 °C
Ar2 max. temperature 220 °C
Ar3 max. temperature 110 °C
Heat Treatment
by Eduard Hryha, Gerd Waning, Lars Nyborg, Akin Malas, Soren Wiberg, Sigurd Berg
33 Carbon control in PM sintering
by Gero Walkowiak
40 Gas- and plasmanitriding – practical aspects in heat treatment shops
Energy Management
by Olaf Irretier
47 Resource savings and energy efficiency in heat treatment shops
Induction Technology
by Marcus Nuding, Christian Krause
53 Inductive hardening of ring gears and pinions
by Dirk M. Schibisch, Martin Bröcking
59 Induction hardening of steering racks for electric power steering systems
2 heat processing 1-2014

1-2014 TABLE OF CONTENTS
61 18
REPORTS
Induction hardening of steering racks
EVENTS
Countdown to GMTN has started
Burner & Combustion
by Ulrich Hofmann, Peter Sänger
65 Burner control and burner management systems in industrial automation systems
by Ales Molinek, Günther Reusch, Josef Srajer, Josef Domagala
73 Application of regenerative burners in forging furnaces
Research & Development
by Sergejs Spitans, Egbert Baake, Andris Jakovics
79 A new approach for coupled simulation of liquid metal flow, free surface dynamics and
electromagnetic field in induction furnaces
heatprocessing
Stay informed and follow us on Twitter
heat processing
@heatprocessing
heat processing is the international magazine for industrial furnaces,
heat treatment & equipment
Essen · http://www.heatprocessing-online.com
1-2014 heat processing
3

TABLE OF CONTENTS 1-2014
77 83
REPORTS
Application of regenerative burners in forging furnaces
RESEARCH & DEVELOPMENT
Simulation of liquid metal flow
Focus On
87 Edition 9: Rolf Terjung
”We want to excel in everything we do”
Profile+
93 Edition 5: International Flame Research Foundation (IFRF)
Technology in Practice
97 Technical monitoring in ene.field – Europe’s project for micro CHP technology
Companies Profile
124 Promat HPI
News
8 Trade & Industry
18 Events
24 Diary
24 Personal
29 Media
98 Products & Services
4 heat processing 1-2014

89
FOCUS ON
Edition 9: Rolf Terjung
Business Directory
104 I. Furnaces and plants for industrialheat treatment
processes
114 II. Components, equipment, production and auxiliary
materials
122 III. Consulting, design, service andengineering
123 IV. Trade associations, institutes, universities,
organisations
123 V. Exhibition organizers, training and education
Are you
playing it
safe?
FCU 500
For monitoring and
controlling central
safety functions in
multiple burner systems
on industrial furnaces.
In accordance to EN 746:2010.
COLUMN
1 Editorial
6 Hot Shots
102 Index of Advertisers
U3 Imprint
Information about the functional safety of
thermoprocessing equipment can be found here:
www.k-sil.de
Elster GmbH
Postfach 2809
49018 Osnabrück
T +49 541 1214-0
F +49 541 1214-370
info@kromschroeder.com
www.kromschroeder.com
1-2014 heat processing

HOT SHOTS
6 heat processing 1-2014

HOT SHOTS
Seven-stand four-high finishing line in a hot strip mill
The seven stands, each fitted with four rolls, convert the
55 m rough strip of steel into an up to 1.8 km long hot strip.
The modernized hot strip mill began operation in early 2013
with the aim of raising production to up to 1.3 million t/a.
(Source: ThyssenKrupp Steel Europe)
1-2014 heat processing
7

NEWS
Trade & Industry
SMS commissions steelmaking plant in Russia
SMS Siemag has successfully commissioned
an electric steelmaking plant at Taganrog
Metallurgical Works of TMK Group in Russia.
The first heat in the Arccess electric arc furnace
was successfully carried
out. The plant at the Taganrog
location is rated for an annual
production of one million tons
of steel.
The new electric steelmaking
plant of SMS Siemag
an replaces an existing
Siemens-Martin steelmaking
plant and meets the required
high environmental standards
by means of advanced
gas cleaning technology and the feeding
of filter dusts back into the melting process.
SMS Siemag has supplied an electric
arc furnace with a tapping weight of 135
tons, the scrap yard equipment, dust collection
and gas cleaning systems as well
as the additive supply system. Further, SMS
Siemag has equipped the installation with
a combined injection system which allows
injecting lime, filter dust and carbon.
The entire electrical and automation
systems have also been provided by SMS
Siemag. It comprises the process automation
(level 1) as well as the technological
process model for the furnace process
(level 2) and the commissioning according
to the tried and tested “Plug & Work”
concept. The main production sites of
TMK Group are Taganrog, Seversky, Volzhsky
and Sinarsky.
Alcoa signs longterm
agreement
with Airbus
Alcoa has signed a multi-year supply agreement
with Airbus valued at approximately
$110 million for value-added titanium and aluminium
aerospace forgings.
Alcoa will produce the parts using its recently
modernised 50,000-ton press in Cleveland,
Ohio. This press uses state-of-the-art controls to
meet stringent aerospace specifications and is
uniquely capable of producing the world’s largest
and most complex titanium, nickel, steel and
aluminium forgings. Alcoa will supply titanium
parts, including forgings used to connect the
wing structure to the engine, for the A320neo,
Airbus’s most fuel-efficient single-aisle jet. The
agreement also includes several large aluminium
forgings for the A330 and A380 - including the
A380 inner rear wing spar, which is the largest
aerospace forging in the world - that will
be made using Alcoa’s proprietary 7085 alloy
intended specifically for large structural aircraft
components. Most of these forgings support the
wing structure where strength-to-weight ratio is
critical to efficient flight performance.
Oerlikon Leybold signs agreements
with Russian company
Oerlikon Leybold Vacuum, one of
the leading global manufacturers
of vacuum pumps and systems,
signed a contract with a distributor
for the Commonwealth of Independent
States CIS region. This contract will
be the basis for a strategic partnership
with Vacuummash, the leading
vacuum pump and –systems suppliers
in Russia and will facilitate the access
to the CIS States. The Joint Stock Company,
JSC Vacuummash, is a leading
vacuum technology company in Russia
and the largest manufacturer of
vacuum systems in the region holding
a market share of around 30 per
cent. Vacuummash has a deep knowhow
on the application requirements
in vacuum technology, especially in
the areas of process industry, R&D
and the energy sector. The company,
which was founded in 1943 and has
been in the vacuum business for more
than 50 years, is deeply anchored with
more than 400 employees in Russia
and the neighboring CIS countries,
having an excellent understanding of
the application requirements of each
field of trade. There has already been
a joint development cooperation and
supply relationship between the two
companies in the field of diffusion and
booster pumps for the last twenty
years. The recently signed, long-term
agreement offers significant advantages
for Oerlikon Leybold Vacuum, so
that in the future, Russian clients in the
areas of metallurgy, chemical, energy,
and research and development will
benefit from this agreement. Accordingly,
Oerlikon Leybold Vacuum will
furnish fore vacuum and high vacuum
products as well as complete vacuum
systems into the Russian market.
8 heat processing 1-2014

Trade & Industry
NEWS
Tata Steel: Electrical steels improve efficiency
Tata Steel subsidiary Cogent Power has
unveiled a range of sophisticated new
electrical steel products which reduce electricity
losses by 20 to 30 % compared with
conventional grain-oriented grades.
The new products are being made at
Cogent Power’s Orb works in Newport,
South Wales. Orb produces cold rolled
grain-oriented electrical steel for the manufacture
of modern electricity transformers
that are used to build and renew the
world’s major power networks.
As global demand for electricity continues
to grow, so does the requirement
from the power industry for products that
enable electricity to be generated and
transmitted more reliably and efficiently.
Stuart Wilkie, Managing Director of Cogent
Power, said: “These new high-grade products
will make a significant contribution
to the preservation of natural resources by
reducing the energy lost in the generation
and transmission of electricity. They benefit
our customers and the whole of society.”
The launch of the new grades follows
the integration in 2011 of Tata Steel’s electrical
steels production route. The Orb
plant now receives hot rolled coil made
in a patented process at the company’s
steelworks at IJmuiden in the Netherlands.
The new grades – M080-23DR,
M085-23DR, M090-27DR and M095-27DR -
support this requirement by enabling the
production of highly efficient steel cores
housed within the transformers used in
energy transmission networks. In addition,
Cogent Power has invested in a new
one-metre wide transformer core cutting
line at its Canadian manufacturing facility
in Burlington, Ontario to meet the needs
of large power transformer manufacturers
in North America.
AFC-Holcroft:
Strength and Innovation since 1916.
Powerful Solutions for the Future.
As a privately owned company with thousands of installations worldwide,
AFC-Holcroft is a worldwide leader in the heat treat equipment industry.
One of the most diverse product lines in the heat treat equipment
industry: Pusher Furnaces, Continuous Belt Furnaces,
Rotary Hearth Furnaces, Universal Batch Quench (UBQ)
Furnaces and Endothermic Generators.
Robust construction and long service life,
designed for ease of maintenance.
Various global facilities in North America, Europe
and Asia for fastest local delivery, service and support.
UBQ: Universal Batch Quench Furnace.
Ultimate in flexibility and versatility.
Modularly constructed universal batch system
with state-of-the-art technology.
Delivers consistently high quality with predicable
and repeatable results.
Get in touch with us today to learn more about how
we can improve your production processes and
how we can give you the edge over the competition.
For further information please visit
www.afc-holcroft.com
AFC-Holcroft USA · Wixom, Michigan AFC-Holcroft Europe · Boncourt, Switzerland AFC-Holcroft Asia · Shanghai, China
1-2014 heat processing
Phone: +1-248-624-8191 Phone: +41 32 475 56 16 Phone: +86-21-58999100
9

NEWS
Trade & Industry
Siemens: Slab caster enters
service at JSW Steel
The new continuous slab caster No. 4
from Siemens Metals Technologies
entered service in August at the Toranagallu
steelworks operated by Indian steel
producer Jindal South West Steel Ltd. (JSW
Steel). The single-strand caster installed in
Steelworks No. 1 has an annual production
capacity of 1.4 million metric tons of
slabs, thereby increasing the total casting
capacity of Steelworks No. 1 to 4.2 million
metric tons. Like continuous slab caster
No. 3, also supplied by Siemens, the new
caster is equipped with the DynaGap Soft
Reduction system.
The resulting high internal quality
of the slabs is the basis for producing
high-quality steel tubes up to X65
in accordance with the API (American
Petroleum Institute) standard, as well as
other micro-alloyed steels. At Steelworks
No. 1 in Toranagallu in the Indian state of
Karnataka, JSW Steel now operates four
continuous slab casters. Casters No. 1
and No. 2 have been in operation since
1999 and were modernized by Siemens
a few years ago. Caster No. 3 has been
in operation since late 2006 and was the
first plant in India in 2009 to be equipped
by Siemens with DynaGap Soft Reduction
technology. The new caster No. 4 is
part of an ongoing expansion program at
JSW Steel. With a machine radius of eight
meters, it has a metallurgical length of
35 meters. Presently, slabs are cast with a
thickness of 220 mm and widths ranging
from 800 to 1,600 mm. The machine has
a design range for future slab thicknesses
of up to 260 mm. The maximum casting
speed is two meters per minute. Thanks
to DynaGap Soft Reduction, slabs can be
cast from high-grade steel tube grades
such as X65 according to the API (American
Petroleum Institute) standard, as well
as other micro-alloyed steels.
ThyssenKrupp
commissions
converter
A
fter a modernization by SMS Siemag,
the 400-ton converter at Thyssen-
Krupp Steel Europe AG, has successfully
produced the first heat at the Duisburg-
Bruckhausen Works in September 2013.
The new converter vessel is one of the
largest of its kind worldwide. The design
developed by SMS Siemag, Germany, has
enabled the construction of a much larger
converter vessel. With an unchanged
quantity of material charged, of up to 400
tons, the internal volume of the converter
has been increased by 24 %. The additional
volumetric capacity enables more
environmentally-friendly process control
and a more efficient energy recovery. SMS
Siemag supplied the vessel, the trunnion
ring, the patented lamella-type vessel suspension
system of the latest generation,
the vessel supporting bearings and the
bearing supports.
The dismantling of the existing converter
platform for the installation of the
plant components as well as the erection
of a new platform has also been
carried out by SMS Siemag. This solution
makes it possible to retain the existing
converter drive.
Preliminary results 2013 for Andritz Group
International technology Group Andritz
announces ad hoc that further financial
provisions in the middle doubledigit
million euro range are necessary
in connection with supplies for a pulp
mill in South America. These provisions
will have a significant negative impact
on the earnings of the Andritz Group in
the fourth quarter of 2013, and consequently
also on the full year results for
2013. The reasons for the provisions are
additional project cost overruns resulting
from strikes on the site and additional
expenses for construction and erection
work. From today’s perspective, there is
no evidence of a need for further financial
provisions – however, they cannot
be excluded. Start-up of the plant is
expected in the first quarter of 2014.
As a result of all the financial provisions
made for the pulp project in South America
in 2013, the EBITA in 2013 is expected to
reach approximately € 200 million and,
after deduction of the provisions already
announced in the third quarter of 2013 for
structural improvement measures planned
in the Schuler Group (acquired by Andritz
in 2013), approximately € 160 million. Sales
of the Andritz Group in 2013 are expected
to amount to between € 5.7 and € 5.8 bn.
Order intake of the Group in the fourth
quarter of 2013 amounted to approximately
1.5 bn. euros, thus order intake of the Group
in 2013 is expected to reach around 5.5
bn. euros. This is an increase of about 12 %
compared to the previous year.
10 heat processing 1-2014

Combined CompetenCe
Trade & Industry
for
NEWS
perfeCt Combustion
systems
Loesche ThermoProzess (LTP) Burner for low-calorific gases, such as
blast furnace gas or coking gas.
The Loesche multi-lance burner (MLB) convinces with its robust construction
its position in heavy industry. The calibration, control range
and service life combined with engineering, combustion equipment
racks and service round up the LTP package for the complete system.
Further information can be obtained on +49 209 361722-0 or at
www.loesche-tp.de
4-2013 1-2014 heat processing
11

NEWS
Trade & Industry
StrikoWestofen
gets new contract
Up to 2014, StrikoWestofen will be in
charge of the refractory lining and
modernization of a total of 14 Westomat
dosing furnaces operated by the AE-
Group. The refractory lining of a dosing
furnace makes a significant contribution
to its efficiency. All new Westomat dosing
furnaces supplied by the StrikoWestofen
Group now have a refractory lining
which is specifically designed in terms of
angles and processes occurring in the
furnace chamber and with regard to the
materials used.
This is necessary to achieve the system’s
excellent values for consumption
and precision. For this reason, it is a good
idea for operators of dosing systems
of this kind to combine the necessary
relining with updating the layout of the
furnace chamber. The AE group, which
has several locations in Germany and
Poland, has now decided to take this
step. The high-pressure die-casting
company has been operating Westomat
dosing furnaces for several years
now. In the framework of the upcoming
relining, StrikoWestofen will equip a
total of 14 systems with state-of-the-art
technology. In the context of the consulting
services, the technicians from
StrikoWestofen carried out a detailed
analysis of the existing situation. This
included measurements of the current
energy consumption as well as thermographic
images.
New orders for Electro-Total
Can-Eng supplies
quench and temper line
Can-Eng Furnaces International has
been contracted to supply a wide plate
quench and temper line for the Steel Authority
of India Limited (SAIL). The equipment will
be installed at the special plate plant facility
of the Rourkela Steel Plant (RSP), Orissa India.
The roller hearth furnace technology will
incorporate a custom designed restrained
roller spray quench that will accommodate
plates from 6 mm to 100 mm in thickness,
and widths from 1200 mm to 3300 mm wide
in a variety of HSLA and proprietary alloys.
The complete turn-key installation
includes Can-Eng’s level II automation
system, predictive modeling software
The Romanian furnace manufacturer Electro-Total
has received different orders.
On the one hand Electro-Total will deliver
to Macon Deva a terracotta firing furnace
with a capacity of 7 t, in order to increase
the production capacity and improve the
efficiency. The furnace will operate at a maximum
temperature of 1,150 °C and will assure
a temperature uniformity of +/- 10 °C for the
whole heating-cooling cycle. Electro-Total
will also upgrade the existing dryer and, for
an increased energy efficiency, the exhaust
gas from the furnace will be connected to
the dryer, in order to recover the waste heat
from the new furnace.
Furthermore the company will deliver
two forging furnaces of 15 m 2 /15 t for heating
of titanium and titanium and zirconium
alloys forging billets to Zirom, manufacturer
of titanium and titanium alloy ingots. The
furnaces will work at 1,300 °C with a temperature
uniformity of +/-10 °C and will be
fitted with flat-flame burners produced by
Elster Kromschröder and recuperators manufactured
by Helmut Peiler Montanwärme
in order to achieve high levels of combustion
efficiency. A sophisticated automation
system will be used for the control of
each furnace. One of the main functions of
these systems will be to provide an oxidizing
atmosphere inside the furnace, controlled by
a combustion flue gas analyzer. This project
will be a premiere in Romania for both the
customer and the supplier.
based on continuous cooling transformation
curves, and numerous other process
enhancements designed into the equipment.
The overall line layout covers a
footprint of 6 m wide by 147 m long, and
includes a roller hearth load table, indirect
fired roller hearth austenitize furnace,
restrained roller spray quench, transfer
tables, roller hearth temper furnace, and
unload tables c/w cooling system and
water filtration circuit. A fall 2014 start-up
is planned. The overall functionality and
product application is based on similar reference
technology Can-Eng installed in the
U.S.A. in the past 7 years.
Loesche wins first PCI mill order in India
With over 25 years experience in manufacturing
coal-grinding mills and
LOMA-Heaters for pulverised coal injection
(PCI) units at steel plants, Loesche has now
supplied more than 60 mills for this specialised
application world-wide. In September
2013, however, the company broke into a new
market when it received an order from the
private-sector Indian steelmaker, Bhushan
Power & Steel Ltd, for a PCI mill for its integrated
plant at Rengali in the state of Orissa. Loesche’s
order includes the design engineering,
supply and installation supervision for an LM
23.2 D coal mill, which will be installed in the
PCI coal grinding and drying section for the
No.2 blast furnace at Bhushan’s steel plant.
The order also includes a LOMA®-Heater that
will be used to dry the pulverised coal during
grinding process. The LM 23.2 D will grind
hard coal at a rate of 42 t/h to a product fineness
of 25 % R 88 μm and a product moisture
content of less than 1 %. With an input power
of typically 450 kW, the two-roller LM 23.2 D
has a grinding table diameter of 2.3 m.
12 heat processing 1-2014

Trade & Industry
NEWS
Trimet to acquire two aluminium plants in France
Trimet Aluminium SE, one of Germany’s
leading aluminum manufacturers, has
submitted a binding offer to acquire two
production plants from Rio Tinto Alcan
in France. With the acquisition of the aluminum
plants in Saint-Jean-de-Maurienne
and Castelsarrasin, Trimet contemplates to
continue its growth strategy and extend its
portfolio of specialized light metal products.
The transaction with Rio Tinto Alcan
is conditional upon the approval of the
regulatory authorities and the execution
of an energy supply agreement and a partnership
arrangement with EDF (Électricité
de France).
The production plants set up by the
French aluminum manufacturer Pechiney
had been taken over by Rio Tinto Alcan. The
internationally active company announced
its intention to dispose of the sites last year.
With a total workforce of over 500, the aluminum
plants produce aluminum wire rod
which is used to make electric cabling for
the energy industry and connecting elements
for the automobile industry, among
other things.
“The region in which the two plants are
located was the cradle of the aluminum
industry. We are both delighted and proud
that we can contemplate maintaining production
and saving jobs in Saint-Jean-de-
Maurienne and Castelsarrasin,” said Heinz-
Peter Schlüter, owner and Chairman of the
Supervisory Board of Trimet Aluminium SE.
“The sites fit in perfectly with Trimet’s strategic
orientation. This applies to the qualified
staff as much as to technical standards
and the superior products. The terms of
the transaction also allow us to envisage
reliable, long-term investment plans.”
The purchase agreement will secure,
among other things, the long-term
supply of aluminum oxide and electric
power, key requirements for the production
of aluminum. The energy supplier
EDF will take a minority stake in the production
plants. Trimet hopes to develop
its successful corporate policy of the past
few years with the new sites. “There is
enormous demand for aluminum wire
rod in the manufacturing industry in
Europe. As a provider of complex alloys
and customized solutions, this product
group will enable us to strengthen our
core competence as a supplier of special
products on a long-term basis,” said Dr.
Martin Iffert, CEO of Trimet.
Setting The Standards For Highest
Efficiency In Thermal Processing
EcoMelter©, 105t per day, cont. 35t
PulsReg® Medusa Regenerator
JASPER
Gesellschaft für Energiewirtschaft und Kybernetik mbH / Bönninghauser Str. 10 / D-59590 Geseke
Telefon: +49 2942 9747 0 / Fax: +49 2942 9747 47 / www.jasper-gmbh.com / info@jasper-gmbh.de
1-2014 heat processing
13

NEWS
Trade & Industry
Trumpf acquires Codatto International
Trumpf is continuing to grow. On
November 22 an Italian company –
Codatto International S.p.a., which specializes
in developing and manufacturing
panel bending machines, became
a member of the corporate group. The
purchase agreement had been signed
in July of 2013; the transaction has now
been completed and ownership has
passed to Trumpf.
This specialist in panel bending
machines is located in the small northern
Italian town of Lonigo, not far from Vicenza.
It employs a staff of 40 and in the 2012
business year reported sales of about five
million euros. Its panel bending machines
complement the Trumpf press brakes perfectly,
offer advantages when dealing with
larger panels, and leave virtually no blemishes
on the material. In this technology,
the panel is clamped down by the presser
foot and the edge hangs over by a bit. This
area is then raised to the desired angle with
a swinging motion.
Ruukki to invest
in steel construction research
Ruukki will conclude separate cooperation
agreements with actors
in the Hämeenlinna region and with
Tampere University of Technology to
strengthen steel construction research
and development. A similar agreement
currently under preparation in the Seinäjoki
region will be included and thus
also secure continued funding for the
Research Centre of Metal Structures in
Seinäjoki and the research professorship
in steel structures. The agreement
will strengthen 15 years of partnership
between Ruukki and HAMK University of
Applied Sciences in the product development
of coated steel sheets and in
the research and testing of steel structures.
New competence will be built at
HAMK’s Sheet Metal Centre, which will
expand activities to cover an increasingly
more significant share of R&D within
steel construction.
Energy efficiency is one of Ruukki’s
strategic focus areas and Ruukki is developing
energy-saving and energy-producing
building products and solutions.
New competences are called for as new
products are brought into use.
Seco/Warwick
completed
furnace
modernization
T
he Furnaces Retrofit and Modernization
Team of the Business Segment Atmosphere
of Seco/Warwick Europe finished the
upgrade of a tempering processing line for
NSK. The successful completion of the first
project led to NSK signing an agreement for
a second modernization and upgrade of a
tempering furnace and processing line at
its Kielce, Poland plant. The second project
should be done in the first half of 2014.
Low order intake at SMS in 2013
As in 2012, the order intake by the SMS
group will be below target for 2013. A
net result well short of the previous year
is anticipated. Dr. Joachim Schönbeck,
spokesman of SMS Holding GmbH, said:
“Low utilization of capacities and continuing
high raw materials prices are making
sales difficult for our customers. That’s
why they have been extremely reluctant
to invest again this year. Just like last year,
order intake has fallen behind our forecasts.
So once again, we have to be ready for
under-utilization of capacity in some areas
in 2014.” This year, the number of employees
including apprentices increased to
some 14,000 (2012: 11,822). The reasons
are the first consolidation of Paul Wurth as
well as takeovers of a few smaller companies,
but also new jobs in China and India.
To ensure high quality, SMS remains committed
to producing the most complex
components of its machinery and plants in
Germany. That’s why the company invested
heavily over recent years in upgrading its
facilities in Hilchenbach and Mönchengladbach.
Yet, parallel to these measures, it also
expanded its production capacity in China.
The focus here is on the provision of better
customer services locally and the construction
of machines specifically designed for
the Chinese market. It is a similar picture
on the Indian market, where another
workshop is currently under construction
and scheduled to start operations in 2014.
Overall, the company is working on cutting
manufacturing costs even more with
production-optimized design plus greater
efficiency in engineering, manufacturing,
and logistics.
14 heat processing 1-2014

Trade & Industry NEWS
Atmosphere furnaces for metal heat treatment
www.soloswiss.com
Conveyor belt furnace
Bell type furnace Profitherm
Continuous furnace
with quenching tank
1-2014 heat processing
SOLO Swiss since 1945
15

NEWS
Trade & Industry
Siemens offers solution for generating steam
from off-gases of electric arc furnaces
Siemens Metals Technologies has developed
a system for recovering heat from
the hot off-gases of electric arc furnaces.
The thermal energy that was previously
discharged unused to the environment is
now used to generate steam. The steam
can be put to good use in other processes
in the steel works or in the generation
of electricity. The system has a modular
structure and can be dimensioned for the
amount of heat to be recovered and integrated
into the existing exhaust gas cooling
system. To maximize the amount of
steam obtained, it can
substitute the complete
conventional off-gas
cooling system in the
electric steel plant. A
possible saving of 22.5
kilowatt hours per metric
ton of steel in the
specific use of energy
was proven in a Turkish
steel mill. If the generated
steam is used to preheat
the feed water in the plant’s in-house
power station, the annual savings potential
amounts to 45,000 metric tons of coal. In
order to cut running costs or to fulfill environmental
regulations, more and more
operators of electric steel mills are banking
on improving the energy efficiency of their
plants. Although the electric steel production
route based on scrap recycling has a
much lower specific energy requirement
than steel production from iron ore, it is
nevertheless an energy-intensive process.
Depending on the method of operation,
up to one-third of the energy used by an
electric arc furnace is lost through offgases.
The sensible heat of the exhaust gases is
usually discharged unused to the environment
through the water and air cooling
systems.
Temperatures of up to 1,800 °C prevail
in the exhaust gas stream. To make these
considerable amounts of energy suitable
for use, Siemens has developed a steam
generation system that can be integrated
into the existing off-gas cooling system of
the arc furnace or can replace it entirely.
The system consists of a boiler including
steam drum, piping, water tanks, pump
groups for feed and boiler water, and the
associated sensors. A group of feed water
pumps supplies the boiler with the necessary
water and ensures the required pressure.
To increase its recovery performance,
the system can be equipped with a feed
water preheating process called an “economizer”.
This economizer heats the water
almost to the boiling point before feeding
it into the steam drum on the boiler.
ThyssenKrupp strengthens market position in Eastern Europe
ThyssenKrupp Ferroglobus, a company
of the Materials Services business area,
has further strengthened its market position
in Eastern Europe. In the Hungarian
capital Budapest the materials experts have
expanded their service center for slitting,
cutting-to-length and plasma cutting, and
opened a new production shop. The new
shop is 4,398 square meters in size. In total
the facility offers 66,948 square meters of
production and storage space. State-ofthe-art
saws, cutting-to-length, slitting,
plasma and torch cutting equipment provide
excellent processing capabilities to
complement the company’s warehousing
services. In addition, a further 4,398 squaremeter
production shop is currently being
built for tube processing. It is due to go
into operation in spring 2014. “The opening
of the new service center continues
our growth and success story in Eastern
Europe,” comments Joachim Limberg, CEO
of the Materials Services business area. With
Poland, the Czech Republic, Russia, Bulgaria,
Slovakia and Hungary, ThyssenKrupp Materials
Services is represented on all the major
markets of Eastern Europe.
16 heat processing 1-2014

Trade & Industry
NEWS
Praxair reports record earnings for 2013
Praxair reported fourth-quarter net
income and diluted earnings per share
of $ 474 million and $ 1.59, respectively.
These results include an income tax benefit
and bond redemption charge. Excluding
these items, adjusted net income and diluted
earnings per share were $ 462 million
and $ 1.55, 12% above the prior-year quarter.
Sales in the fourth quarter were $ 3,010
million, 10% above the prior-year quarter
excluding currency translation effects.
Organic sales increased 7% with growth
across all geographic segments due primarily
to energy, metals, chemicals and
manufacturing markets. Acquisitions in
North America and Europe contributed 3%
growth in the quarter. Sales were steady
sequentially from the third quarter due primarily
to higher price offset by seasonally
lower volumes.
Operating profit in the fourth quarter
was $ 690 million, 12 % above the prioryear
quarter. The increase was driven by
volume growth, higher pricing and acquisitions,
partially offset by negative currency
translation effects. Operating profit as a
percentage of sales was a record 22.9%.
Fourth-quarter cash flow from operations
was a record $ 964 million. Cash flow funded
$ 516 million of capital expenditures,
largely for new production plants under
long-term contracts with customers, $177
million of dividends and $ 86 million of
stock repurchases, net of issuances.
For full year 2013, reported net income
was $ 1,755 million and reported diluted
earnings per share was $ 5.87. On an adjusted
basis, full-year net income was $ 1,772 million
and diluted earnings per share was $ 5.93,5 %
and 6 % above the prior year, respectively.
Full-year sales were $ 11,925, 8 % above
2012, excluding negative currency translation.
Growth was driven by stronger
volumes, higher pricing and acquisitions.
Reported operating profit was $2,625 million.
Adjusted operating profit of $ 2,657
million was 8 % above 2012, excluding
negative currency translation.
For the full year, cash flow from operations
was a record $ 2,917 million, about
25 % of sales. Capital expenditures were
$ 2,020 million. The company invested
$ 1,323 million in acquisitions, including
the NuCO 2 micro-bulk carbon dioxide
business in the United States, Dominion
Technology Gases and several U.S.
packaged gas distributors. The company
paid dividends of $ 708 million and
repurchased $ 436 million of stock, net
of issuances.
www.burkert.com
All inclusive!
What you see here is the essence of universality.
Perfect for whenever you require a direct-acting
2/2-way solenoid valve. It’s the one valve you can use
for each and every occasion. Built for both neutral
and slightly aggressive media – powerful enough to
work with dry gases or steam. Three design elements
ensure you get maximum performance: its highest
flow rates, its long service life and its top reliability.
All of which come standard. And it’s no problem at all
if your processing environment demands additional
features – from more pressure and a different supply
voltage, to an Ex version. Simply universal: our
solenoid valve 6027.
We make ideas flow.
1-2014 heat processing
Solenoid Valves | Process & Control Valves | Pneumatics & Process Interfaces | Sensors | Transmitters & Controllers | MicroFluidics | Mass Flow Controllers | Solenoid Control Valves
17

NEWS
Events
Great reception of Metal + Metallurgy China 2014
Metal + Metallurgy China will be held
from May 19 to 22, 2014 at China
International Exhibition Center (New Venue)
in Beijing, covering a exhibiting space of
106,000 m 2 . It is estimated that there will
be about 1,400 companies exhibiting and
90,000 industry professionals visiting the fair.
With a history of over 20 years Metal +
Metallurgy China is regarded as the largest
exhibition in the hot metal processing
industry in Asia and the second largest in
the world. Following China’s rapid industrialization
process, Metal + Metallurgy China
keep on enriching the content and refining
the category. Cast parts, refractory materials
and ceramics, which are widely used in auto,
machine tools, shipbuilding, engineering
machinery, rail transit and other manufacturing
areas, are introduced to the exhibition.
To cater to the increasing demand of
the exhibitors, Metal + Metallurgy 2014
embraces the update of the international
halls. The total exhibiting area of international
hall grows to 20,000 m 2 . This year,
Hall W1 and part of W2 will be at serving
all the overseas enterprises.
So far, 90 % of exhibiting area at international
halls is sold. Visitors can expect
American pavilion, German pavilion, Italian
pavilion, Spain pavilion and Taiwan pavilion
in Hall W1. As for Hall W2, international
brands including HA, Fuji Electric, ASK, MTS,
KAO have claimed their participation. Iranian
companies will have their first debut
as national pavilion. For further information
please visit: www.mm-china.com
Hardmetals Short
Course of the EPMA
Following the successful Sintering Courses in 2012
and 2013, the European Powder Metallurgy Association
(EPMA) has organised an intensive 2-day course
on Hardmetals for 2014 taking place in Vienna, Austria,
9-11 April 2014.
The 2014 Short Course will provide an excellent
learning opportunity for engineers and scientists
with an interest in hardmetals. Thanks to the unique
combination of high level industrial specialists and
academics from across Europe this course will provide
unrivalled insights into the practical capabilities and
applications of hardmetals as applied to the powder
metallurgy (PM) process.
The two-day course will start with an Overview
of Hard Materials (HSS to Diamond) and a History of
Hardmetals. Subsequent sessions will include:
■■
■■
■■
■■
■■
■■
■■
Raw Material Sources,
Manufacturing Routes for Raw Materials,
Shaping, Sintering, Finishing,
Cemented Carbides,
Calphad,
Dictra for Metallurgical Engineering,
Application FE Simulation amongst others.
The Hardmetals Short Course is organised by the
European Hard Materials Group (EHMG) of the EPMA
with support from its members. The technical course
content has been selected by Dr. Leo Prakash and Dr.
Steven Moseley. For further information please visit:
www.epma.com/shortcourse
Countdown to The Bright World
of Metals 2015 has started
Potential exhibitors at the metallurgical
trade fair highlight in
Düsseldorf in 2015 have been able
to register since January: the four
successful trade fairs GIFA, METEC,
Thermprocess and Newcast are
being held again in Düsseldorf
under the motto “The Bright World
of Metals” from 16. to 20. June 2015.
Like the other three
trade fairs Thermprocess
has a long tradition too:
the international trade
fair has been the place to
find innovative thermo
process technology since
1974. Presentation of the
latest trends for solutions
relating to the production and operation
of industrial furnaces and heat
treatment plants enables visitors to
obtain information that keeps them upto-date
with industry developments.
The range includes industrial furnaces,
industrial heat treatment plants and
thermal processes, equipment for special
uses, components, equipment and
other supplies, occupational safety and
ergonomics. Both exhibitors and visitors
gave Thermprocess 2011 top marks:
96 % of them said that their involvement
in the trade fair had been a complete
success, for example. All in all, 305
companies from 30 different countries
presented their products and services
to 7,900 visitors, 45 % of which came
from outside Germany.
The start of the countdown to
The Bright World of Metals with the
initiation of the registration
process marks
the beginning of the
intensive preparatory
phase for the trade fair
staff in the exhibitor
department, because
the registration process
officially ends as early as
30. April 2014. This means that companies
should decide in the very
near future whether they want to
exhibit at the leading trade fairs for
the metallurgical industries. Online
registration is possible via the trade
fair portals not only for companies
that have already participated in
the trade fairs in the past but also
for potential new participants.For
further information please visit:
www.thermprocess-online.com
18 heat processing 1-2014

Events
NEWS
Hannover Messe 2014: lead
theme Integrated Industry
Materials like steel, ceramics, plastic
and rubber define industry today.
When used with new manufacturing
methods, they are also opening up new
pathways for a successful future. These
pathways all point towards the very timely
business and environmental focus on
energy efficiency – in two ways: production
processes are becoming more energy
efficient, and they are opening up new
possibilities for generating and using energy
more efficiently. As the leading global
trade show for industrial supply solutions
and lightweight construction, Industrial
Supply provides an international platform
for these new material developments at
Hannover Messe 2014.
Good old steel is playing a central role in
the energy transition in Germany, according
to a study by Boston Consulting Group
together with steel business and research
organization Stahl Institut VDEh. Steel is
what makes the construction of high efficiency
power plants and renewable energy
generation possible. Using innovative
steel products saves six times more CO 2
than is generated by producing the steel
needed for them. This is because German
steel manufacturers are among the world’s
most efficient companies when it comes to
primary steel production.
The Bulk Forming
Industry Association
is again hosting
a major stand
with its member
companies at
Industrial Supply
in 2014. Additional
individual exhibitors
also present at
the theme park.
The Bulk Forming
theme park
focuses in particular
on trends and technical
innovations
in material and
resource efficiency.
Materials play a significant
role in this
field, which is why
extensive research
is being devoted to
materials for bulk
Cover
SMS Elotherm
Induction solutions.
Hard to beat!
Elotherm is a worldwide technology leader and your reliable partner
for high performance induction machines and technologies.
With pioneering designs tempered by many decades of industrial
experience, SMS Elotherm designs and builds both individual
machines and complete systems for seamless integration into your
production line.
Induction heating and heat treatment lines
■
Induction heating of metals
for forging and rolling
■
Induction hardening and
quench & temper
■
Induction welding, annealing
and special technology for tubes
www.sms-elotherm.com
■
Continuous induction
strip heating
■
Induction kinetics
■
Laser technology
■
Global service
forming. The next Hannover Messe will
run from 7 to 11 April 2014 and feature the
Netherlands as its official Partner Country.
The trade fair will comprise seven flagship
fairs: Industrial Automation, Energy,
MobiliTec, Digital Factory, Industrial Supply,
IndustrialGreenTec and Research & Technology.
The upcoming event will place a
strong emphasis on Industrial Automation
and IT, Energy and Environmental Technologies,
Industrial Subcontracting, Production
Engineering and Services and Research
& Development. For further information
please visit: www.hannovermesse.com
7 th Colloquium “Modelling for Electromagnetic Processing”
The MEP 2014 – the 7 th International
Scientific Colloquium on Modelling for
Electromagnetic Processing is taking place in
Hannover/Germany in September 16-19, 2014.
In tradition of the international scientific colloquiums
Modelling for Material Processing in
Riga in 1999, 2001, 2006, 2010 and Modelling
for Electromagnetic Processing in Hannover
in 2003 and 2008 the Institute of Electrotechnology
of the Leibniz University of Hannover
and the University of Latvia organize the next
colloquium Modelling for Electromagnetic
Processing in Hannover 2014.
Recent results of numerical and experimental
research activities in the field of industrial
processing technologies for creating new
and alternative materials, materials with highest
quality and purity and new innovative
products will be presented at the colloquium.
The organizers expect up to 100 international
participants from universities and
research centres as well as from industrial
suppliers and users of electromagnetic and
electrothermal processes who will hear lectures
on the following topics:
■■
Numerical and physical modelling for
■■
■■
■■
■■
electromagnetic processing of new and
high quality material,
Crystal growing of semi-conductive
material,
Dielectric heating of non-conductive
materials,
Production processes for new and innovative
products,
Energy efficiency and sustainability of
industrial processes.
For further information please visit:
www.mep2014.uni-hannover.de
1-2014 heat processing
19

NEWS
Events
Technology double-pack wire and Tube 2014
The two globally leading trade fairs wire
and Tube will be staged - for the 14 th
time already – at the Düsseldorf Exhibition
Centre from 7 to 11 April 2014. On a total
net floor space of more than 100,000 m 2 ,
they will showcase the accumulated technology
prowess of the wire, cable and tube
manufacturing and processing sectors.
More than 2,000 exhibitors are presenting
their latest technologies and products at
Düsseldorf fairgrounds.
The range of offerings at wire 2014 will
cover a wide spectrum, from wire manufacturing
and finishing equipment, mesh welding
machinery, process engineering tools and
auxiliary components all the way through to
input materials and speciality wires. Innovative
solutions from the cable, measurement,
control and test engineering sectors round
off the portfolio, and specialised sectors such
as logistics, conveying systems and packaging
will also be represented. In total more
than 1,200 exhibitors will present their latest
products and technologies on an exhibitions
area of 58,000 m 2 .
The wire event will be spread out across
Halls 9 to 12 and 15 to 17. The areas wire,
cable and fibre optic machinery, and wire
and cable production and trade will be
located in Halls 9 to 12, 16 and 17. Fastener
technology can be found in Hall 15; spring
making and mesh welding machinery will
be located in Hall 16. For the first time, the
mesh welding machinery sector will have
its own compact presentation forum – a
Special Show in just one hall.
The Tube event will present its 2014
ranges in Halls 1 to 7.0 and Hall 7a. The sector’s
entire range will be on display, from
tube manufacturing to tube processing
and finishing. More than 1,100 exhibitors
have applied on a total of 50,000 m 2 .
Additional exhibits will range from tube
materials, tubes and accessories, tube
manufacturing machinery and secondhand
equipment to process engineering
tools and auxiliary components all the way
through to measurement and control technology.
Test technology and specialised
areas such as stock automation and control
systems will supplement the extensive
ranges.
Tube accessories will be found in Halls 1
and 2, whereas Tube trading and manufacturing
will be located in Halls 2 to 4 and Hall
7.0./7.1. Also in Hall 2 - the China Pavilion!
Look for forming technology in Hall 5 and
for pipe and tube processing machinery
in Halls 6 and 7a. The plant and machinery
area will be in Hall 7a and sections will be
found throughout Halls 1 to 7.0.
For further information please visit:
www.wire.de or www.tube.de
Trade fair trio Metallurgy Litmash, Tube Russia,
Aluminium/ Non-Ferrous 2014
The 14 th Metallurgy Litmash, Tube Russia,
Aluminium/ Non-Ferrous 2014 follows
on from the successful event held in June
2013. 3 to 6 June 2014 will see the trade
fair being staged again at the Moscow fair
grounds Expocentre. The trade fair trio
confirms once more its leading function
as the most important trade and contact
platform for the metallurgical and tube sectors
in Russia and its neighbouring states.
The quality metal and tube processing
and finishing range offered at this year’s
event attracted a total of 330 exhibitors
and 10,850 visitors from 51 countries to
Moscow; of the visitors 95 % were trade
visitors and 68 % came from top and middle
management. The amount of foundry
technology visitors increased considerably
over the previous year.
The trade fair makes it perfectly clear
that Russia and its neighbouring states are
among the fastest growing regions worldwide.
The Russian market for machinery and
equipment is lucrative and forecasts say
that demand for metal working machines
in Russia will triple by 2016 reaching an
annual volume of € 2.5 billion. The investment
made by Russian and foreign enterprises
in the modernisation or construction
of new production lines in the country is
rising constantly. German manufacturers
are both sought-after suppliers and investors.
For Metallurgy Litmash, Tube Russia,
Aluminium/ Non-Ferrous this means: the
demand for high-calibre ranges from international
manufacturers is also rising.
Metallurgy Litmash, Tube Russia and
Aluminium/ Non-Ferrous 2014 receives
valuable support from VDMA e.V. (German
Engineering Federation), from EUnited
Metallurgy (European Metallurgical Equipment
Association), from CECOF (The European
Committee of Industrial Furnace and
Heating Equipment Associations) and from
CEMAFON (The European Foundry Equipment
Suppliers Association).
For further information please visit:
www.metallurgy-tube-russia.com
20 heat processing 1-2014

Events
NEWS
1-2014 heat processing
21

NEWS Events
join the best
7 – 11 April 2014
Düsseldorf, Germany
International Wire and Cable Trade Fair
International Tube and Pipe Trade Fair
Meeting point: wire 2014 and Tube 2014
in Düsseldorf!
join the best – welcome to the world’s leading trade fair for the tube, wire and
cable industry! Those who wish to find comprehensive information about the latest innovations
both in wire and tube manufacturing and processing need look no further. It can all be found here
at the world’s most important exhibitions. A focal point of wire 2014: The growing importance
of copper wires in automotive engineering, in telecommunication or electronics. Special focal
point at Tube 2014: Plastic tubes. A special area is reserved for them, because the question of
materials is becoming more and more important.
An important fixed date in your calendar – your visit to wire 2014 and to Tube 2014 in Düsseldorf!
www.wire.de
www.tube.de
Messe Düsseldorf GmbH
P.O. Box 10 10 06 _ 40001 Düsseldorf _ Germany
22
Tel. +49 (0)2 11/45 60-01 _ Fax +49 (0)2 11/45 60-6 68
heat processing 1-2014
www.messe-duesseldorf.de

Events
NEWS
Tecnargilla 2014: majority of exhibition spaces already taken
The 24 th Tecnargilla event, important
ceramic technologies fair, scheduled
for 22 to 26 September 2014 at the Rimini-
Fiera exhibition area, promises to be yet
another success. 80 % of the exhibition
spaces occupied at the last event, held in
2012, have in fact already been confirmed
by exhibitor companies. This once again
evidences Tecnargilla’s worldwide leadership
of fairs in this sector, and the indispensable
nature of the event for operators.
There is also a rise in the number of exhibitors
who will take part in the trade fair for the
first time or return to Rimini after missing a
few events. The leading Italian and foreign
companies operating in technology and
design supplies for the ceramic and brick
industry will therefore be present in force in
Rimini. They are already at work to present a
preview of their latest innovations to international
customers at the fair.
Tecnargilla will in fact welcome foreign
operators from all five continents,
representing both major ceramic groups
Euroguss 2014 closed with a triple record
Euroguss in Nuremberg closed on 16 January
with a triple record: over 11,000 trade
visitors (2012: 8,415), a good 30 % of them
international, came to the 470 exhibitors
(2012: 383). In short, the 10 th anniversary of
the International Trade Fair for Die Casting
– Technology, Processes and Products was
a complete success.
This was also reflected by the broad and
attractive range of products and services for
the die casting value chain. Die casting foundries,
component suppliers and scientific institutions
presented die castings, materials, furnaces,
die casting machines, moulds, processes
for finishing treatment, quality control and the
latest findings from research & development.
The die casting foundries and their
component suppliers, equipment suppliers
and service providers came to Nürnberg
from altogether 26 countries. The
strongest exhibiting nations after Germany
were Italy, Sweden, the Czech Republic,
Austria and Switzerland. The international
share of visitors also increased appreciably:
over 30 % were international visitors, mainly
from Italy, Austria, the Czech Republic,
Turkey and Switzerland.
Tradition, innovation and a look into the
future were ideally combined at the tenth
Euroguss, so the special anniversary also took
a look back. The special show entitled “Origins
of the Future”, organized in cooperation
2 nd edition of Aluminium Brazil in April 2014
Just a few weeks before
the kick-off of the
World Cup in São Paulo
in summer of 2014, the
international aluminium
industry will gather there for Aluminium
Brazil 2014 from 1 to 3 April. Like the debut
event two years ago, the second edition of
the trade fair will take place once again as
part of ExpoAlumínio, the most important
industry meeting of the aluminium sector
in South America. A total of 170 exhibitors
are expected for ExpoAlumínio, from CBA,
the largest aluminium producer in Brazil,
to key global players such as Aloca, Hydro,
Novelis, Pyrotech and Wagstaff. Most of the
international exhibitors will be consolidated
under the umbrella of Aluminium Brazil,
which accompanies ExpoAlumínio: Some
50 exhibitors from Europe, the Middle East
and Asia will be represented there. The largest
exhibitor nation this year – behind Brazil
– will be China. ExpoAlumínio is organised
every other year by Reed Exhibitions Alcantara
Machado and the Brazilian aluminium
association ABAL. The trade fair supporting
worldwide and new production innovations.
They share the common need to
seek new technologies able to improve and
optimise the production process – making
it more environmentally friendly, as well as
new design solutions that will increase the
added value of their products.
The last event brought together in
Rimini 450 exhibitors from 29 countries and
30,458 visitors, including 14,822 foreign visitors
from 110 countries. For further information
please visit: www.tecnargilla.it
with exhibitors and associations, attracted
great interest. Historical castings and tools
showing the innovativeness of the sector and
individual companies and institutions offered
a welcome look back to bygone times.
The next Euroguss takes place in the Exhibition
Centre Nuremberg from 12 to 14 January
2016. For further information please visit:
www.euroguss.com
programme will include the 6 th International
Aluminium Conference and the International
Seminar for Aluminium Recycling.
More than 12,000 visitors attended the previous
ExpoAlumínio event two years ago.
With the inclusion of Aluminium Brazil in
its portfolio, Reed Exhibitions Deutschland
has expanded the global activities of the
Aluminium World Trade Fair and now
provides globally operating enterprises
a targeted point of entry into the Latin-
American market. For further information
please visit: www.aluminium-brazil.com
1-2014 heat processing
23

NEWS
Personal
DIARY
11-15 March
1-3 April
7-11 April
7-11 April
6-8 May
19-22 May
3-6 June
3-6 June
9-11 July
4-7 Sep.
9-11 Sep.
16-18 Sep.
16-19 Sep.
21-24 Sep.
7-9 Oct.
Metav 2014
in Düsseldorf, Germany
www.metav.com
Aluminium Brazil 2014
in São Paulo, Brazil
www.aluminium-brazil.com
wire + Tube 2014
in Düsseldorf, Germany
www.wire.de
www.tube.de
Hannover Messe
in Hannover, Germany
www.hannovermesse.com
Fabtech
in Mexico City, Mexico
www.fabtechmexico.com
Metal & Metallurgy China
in Beijing, China
www.mm-china.com
Metallurgy Litmash
in Moscow, Russia
www.metallurgy-tube-russia.com
Metalforum
in Poznań, Poland
www.metalforum.mtp.pl
Aluminium China 2014
in Shanghai, China
www.aluminiumchina.com
Minerals, Metals, Metallurgy & Materials
in New Delhi, India
www.mmmm-expo.com
Heat Treatment 2014
in Moscow, Russia
www.htexporus.com
Metal 2014
in Kielce, Poland
www.metal.targikielce.pl
MEP 2014 Modelling for Electromagnetic Processing
in Hannover, Germany
www.mep2014.uni-hannover.de
EuroPM 2014
in Salzburg, Austria
www.epma.com/pm2014
Aluminium 2014
in Düsseldorf, Germany
www.aluminium-messe.com
Thomas Dopler is
new CEO of Aichelin
D
r. Thomas Dopler (photo) took on his
new role as CEO of Aichelin Ges.m.b.H.
in Mödling, Austria, on 1 January 2014. The
previous CEO, Dipl.-Ing. Manfred Hiller, will
enter his well-earned retirement on 31
March 2014.
Dopler started his career as a research
associate at the École Centrale in Paris. He
then became head of the development
department of Pechiney Aviatube in Montreuil-Juigné,
a supplier of aluminium parts
for the aviation industry. His next sojourn
was at voestalpine, where he managed several
projects in the automotive sector and
was director for business development in
the segment automotive France. Later, he
also accompanied the introduction of the
phs-ultraform technology in the automotive
industry.
Since 2008, Dr. Dopler has been gaining
experience in the heat treatment sector as
head of the sales department at Aichelin
Ges.m.b.H., and since 2012 also as head of
the Safed conveyor belt furnace product
line in Mödling.
24 heat processing 1-2014

Personal
NEWS
Michael Jungnitsch named new CEO of the VDE Institute
Dipl.-Ing. Michael Jungnitsch (photo)
has been designated as the new
CEO of VDE Testing and Certification
Institute in Offenbach, Germany. Effective
March 1, 2014, Jungnitsch (51) – former
Chief Regional Officer of TÜV Rheinland
in Asia-Pacific – will succeed Dipl.-Ing.
Dipl.-Kfm. Wilfried Jäger, who is retiring
after serving as head of the VDE Institute
for 18 years.
The designated CEO Michael Jungnitsch
has extensive expertise and
experience as an electrical engineer,
Asia expert, and manager in the area
of product testing and certification. He
studied electrical engineering in Bochum
and engineering management in Vienna.
In the TÜV Rheinland Group, he held a
variety of positions, including Managing
Director in Korea and Japan and head of
product safety in Germany. Jungnitsch is
actively engaged in many international
organizations and representations of
interests.
As CEO of VDE Testing and Certification
Institute, Jungnitsch will head a
world-renowned institution in the field
of testing and certification of electrical
and electronic devices, components and
systems.
57 th INTERNATIONAL COLLOQUIUM ON REFRACTORIES 2014
September 24 th and 25 th , 2014 . EUROGRESS, Aachen, Germany
} Pig iron
} Steel
} Cast iron
} Corrosion
Conference Topic
Refractories for Metallurgy
} Light metals
} Non ferrous metals
} Metallurgy
} Continuous casting
The deadline for submission of abstracts is 10 th March 2014
For further information please contact:
} Foundry technic
} Shaped and unshaped
refractories
} Installation and
full-line service
} Wear
} Isolating material
} Recycling
} Functional products
1-2014 heat processing
ECREF European Centre for Refractories gemeinnützige GmbH
– Feuerfest-Kolloquium –
Rheinstraße 58 · 56203 Höhr-Grenzhausen · GERMANY
Tel.: +49 2624 9433 125 · Fax: +49 2624 9433 135
E-Mail: events@ecref.eu · Internet: http://www.ecref.eu 25
www.feuerfest-kolloquium.de

NEWS
Personal
Richard G. Kyle new member of Timken’s board of directors
Richard G. Kyle
(photo), who
was appointed chief
operating officer in
September 2013,
currently oversees
all aspects of the
Timken bearings
and power transm
i s s i o n
business
including
the aerospace,
process
and mobile industries segments. At
the time of that appointment, the Timken
board of directors indicated it expects
Kyle to succeed current Timken President
and CEO James W. Griffith when he retires
from the company and the board in 2014.
Kyle began his career at Timken in
2006 as vice president of manufacturing
and was named president of the
aerospace and mobile industries segments
in 2008. In 2012, Kyle was named
group president of Timken, responsible
for the aerospace and steel segments as
well as the engineering and technology
organization. Prior to Timken, Kyle held
management positions with Cooper
Industries and later was named vice
president of operations for a division of
Hubbell, Inc.
A native of Mishawaka, Ind., Kyle
received a bachelor’s degree in mechanical
engineering from Purdue University and
earned a master of business administration
degree in management from Northwestern
University’s Kellogg Graduate School of
Management. He also serves on the board
of directors of the United Way of Greater
Stark County.
Eclipse: new vice president of engineering
and vice president of finance
Eclipse, Inc., a worldwide manufacturer
of industrial burners and combustion
systems in December 2013 announced the
promotion of Kim Droessler to Vice President
of Engineering. The Vice President
Kim Droessler
of Engineering role includes responsibility
for the entire product life cycle from
inception through obsolescence including
new product development. His role is also
responsible for driving and managing our
Rick Steder
engineering standards and best practices
as they apply to designing products and
configured systems.
Furthermore the company announced
the promotion of Rick Steder to
Vice President of Finance. This position
includes responsibility for consolidating
financials for all of the Eclipse worldwide
facilities. Steder will also retain his role
as Chief Compliance Officer. Eclipse, Inc.
has been at the forefront of the combustion
industry for over 100 years.
Founded in 1908, and in its third generation
of family ownership, Eclipse is
recognized as a worldwide leader in
providing innovative thermal solutions
that are safe, reliable, efficient, and clean.
Eclipse, Inc. designs and manufactures a
wide variety of gas and oil burners, recuperators
and heat exchangers, complete
combustion systems, and accessories for
combustion systems.
26 heat processing 1-2014

Events
NEWS
4
ALUMINIUM 2014
7–9 Oct 2014 | Messe Düsseldorf
10th World Trade Fair & Conference
www.aluminium-messe.com
Organised by
1-2014 heat processing
Partners
27

NEWS
Events
28 heat processing 1-2014

Media
NEWS
Handbook of Aluminium Recycling
The Handbook has proven to be helpful to
plant designers and operators for engineering
and production of aluminium recycling
plants. The book deals with aluminium
as material and its recovery from bauxite,
the various process steps and procedures,
melting and casting plants, metal treatment
facilities, provisions and equipment
for environmental control and workforce
safety, cold and hot recycling of aluminium
including scrap preparation and remelting,
operation and plant management. Due to
more and more stringent regulations for
environmental control and fuel efficiency as
well as quality requirements sections about
salt slag recycling, oxy-fuel heating and heat
treatment processes are now incorporated in
the new edition. The reader is thus provided
with a detailed overview of the technology
of aluminium recycling.
The Gas Engineer’s Dictionary
he Gas Engineer’s Dictionary” is a
“Tnew designed reference book for
both engineers with professional experience
and students of supply engineering.
The opus contains the world of supply
infrastructure in a series of detailed
professional articles dealing with main
points like the following:
■■
■■
■■
■■
■■
biogas,
compressor stations,
conditioning,
corrosion protection,
dispatching,
■■
■■
■■
■■
■■
■■
■■
■■
gas properties,
grid layout,
LNG,
odorization,
metering,
pressure regulation,
safety devices,
storages.
This dictionary will be a standard work for
all aspects of construction, operation and
maintenance of gas grids.
Innovation in Electric Arc Furnaces
This book equips a reader with knowledge
necessary for critical analysis of innovations
in electric arc furnaces and helps to
select the most effective ones and for their
successful implementation. The book also
covers general issues related to history of
development, current state and prospects
of steelmaking in Electric Arc Furnaces.
Therefore, it can be useful for everybody
who studies metallurgy, including students
of colleges and universities.
The modern concepts of mechanisms of
Arc Furnace processes are discussed in the
book at the level sufficient to solve practical
problems: To help readers lacking knowledge
required in the field of heat transfer
as well as hydro-gas dynamics, it contains
several chapters which provide the required
minimum of information in these fields of
science. In order to better assess different
innovations, the book describes experience
of the application of similar innovations
in open-hearth furnaces and oxygen
converters. Some promising ideas on key
issues regarding intensification of the heat,
which are of interest for developers of new
processes and equipment for Electric Arc
Furnaces, are also the concern of the book
It should be noted, that carrying out the
simplified calculations as distinct from using
"off the shelf" programs greatly promotes
comprehensive understanding of physical
basics of processes and effects produced
by various factors.
INFO
by Christoph Schmitz
2 nd edition 2014
approx. 500 pages,
hardcover
€ 130.00
ISBN:
978-3-8027-2970-6
www.vulkan-verlag.de
INFO
by Klaus Homann,
Rainer Reimert,
Bernhard Klocke
1 st edition 2013
452 pages, hardcover
€ 160.00
ISBN:
978-3-8356-3214-1
www.vulkan-verlag.de
INFO
by Yuri N. Toulouevski,
Ilyaz Y. Zinurov
2 nd edition 2013
282 pages, hardcover
€ 106.99
ISBN:
978-3-642-36272-9
www.springer.com
1-2014 heat processing
29

NEWS
Media
INFO
by Erwin Dötsch
2 nd edition 2013
322 pages, hardcover
€ 75.00
ISBN:
978-3-8027-2386-5
www.vulkan-verlag.de
Inductive Melting and Holding
The second, revised edition of this standard
work for engineers, technicians and
other practitioners working in melting shops
and foundries appeared in mid-2013. This
new version of the title on inductive melting
and temperature maintenance originally
published in 2009 is the result of the
great demand generated at that time, and
includes coverage of the plant- and processengineering
advances achieved during the
intervening four years. These relate, in particular,
to the use of the induction furnace in
electric-steel production, a field in which this
environmentally and mains-friendly melting
system has evolved into a genuine and
advantageous alternative to the electric arc
furnace. Characteristic of this is the recent
increase in inverter supply power from its
maximum of 18 MW at the time of publication
of the first edition of the book to its
present 42 MW to permit supply of 65 t crucible
furnaces.
INFO
by Arthur J. McEvily,
Jirapong Kasivitamnuay
2 nd edition 2013
504 pages, hardcover
€ 120.00
ISBN: 978-1-118-16396-2
www.wiley.com
Metal Failures
Failure analysis is of critical importance
in the world today. This is due in part to
the high cost in lives and money of catastrophic
failures that may have been prevented.
Failures effect structures in a broad
range of industries from machinery to aircraft,
building structures, and as we've seen
recently nuclear power facilities. To analyze
failure, engineers and designers need to
understand not only what happened but
also how, from a structural point-of-view,
the failure occurred. An outcome of a successful
investigation may lead to improvements
in design and manufacture which
preclude a particular type of accident from
happening again. An investigation may also
lead to a proper assignment of responsibility
either to the operator, the manufacturer,
or the maintenance and inspection organization
involved.
McEvily's book is one of the only available
that covers not only how failure occurs
but also the examination methods developed
to expose the reasons for failure.
The new edition will contain updates of
all chapters plus new coverage of; elastic
behaviour and plastic deformation, localized
necking, the phenomenological
aspects of fatigue, fatigue crack propagation,
alloys and coatings, tensors and tensor
notations, and much more.
The book is a revision of a well-known
classic that is considered to have the most
comprehensive coverage of both the
"how" and "why" of metal failure. It features
separate chapters on key failure mechanisms
and includes excellent case studies
and examples. Furthermore, it covers statistical
data, report writing, legal testimony,
and more.
HOTLINE Meet the team
Managing Editor: Dipl.-Ing. Stephan Schalm +49(0)201/82002-12 s.schalm@vulkan-verlag.de
Editorial Office: Annamaria Frömgen +49(0)201/82002-91 a.froemgen@vulkan-verlag.de
Editor: Thomas Schneidewind +49(0)201/82002-36 t.schneidewind@vulkan-verlag.de
Editor (Trainee): Sabrina Finke +49(0)201/82002-15 s.finke@vulkan-verlag.de
Advertising Sales: Bettina Schwarzer-Hahn +49(0)201/82002-24 b.schwarzer-hahn@vulkan-verlag.de
Subscription: Martina Grimm +49(0)931/41704-13 mgrimm@datam-services.de
30 heat processing 1-2014

Media
MPI14014_HeatPro_GB_METAV_89x255_METAV 2014 28.11.13 18:06 Seite 1
NEWS
Roland Berger Study:
Evolution of service
INFO
by Roland Berger
Strategy Consultants
December 2013
www.think-act.com
11 –15 March
Düsseldorf
Aftersales services have always played an important role
at German, Austrian and Swiss engineering companies.
Up to 65 % of profits now result from selling various aftersales
services. But sales and profits from traditional offerings such
as spare parts and machine maintenance are declining ever
faster. To counteract this trend, engineered product and
plant manufacturers should rethink their business models
and develop new services. That is the conclusion of the new
study, “Evolution of service”, for which Roland Berger Strategy
Consultants surveyed 30 companies in Germany, Austria and
Switzerland about their aftersales services business.
Companies whose aftersales business makes up at least a
third of their total sales can chalk up EBIT margins of over 10 %
in this area.
Spare parts and maintenance still make up, on average,
42 % of the sales generated by aftersales services. But margins
in these traditional services are falling due to the high level of
standardization. Spare parts, for example, can often be bought
more cheaply from third parties.
For example, upgrades and updates to existing plant software
plus assessment and analysis tools offer major business potential
for the industry. Advice is becoming ever more important to
help customers pinpoint suitable machines with the right technological
features and the required size. But despite the growth
potential in aftersales services, providers still have a lot of catching
up to do. Just 55 % of the engineering companies surveyed
are capable of selling services for installed plant and equipment.
One key growth driver in engineering is remote monitoring,
the wireless transmission of data from the installed equipment
to the manufacturer. This technology enables remote diagnosis
of faults and ensures problems are resolved rapidly. Beyond
that intelligent analysis of customer data helps engineering
companies to optimize their equipment – according to the
customers’ precise needs.
Currently, 80 % of plant manufacturers already receive important
information about the usage of the machinery installed.
But few of them can actually analyze this data to offer their
customers true value added.
Special Shows
Verein Deutscher Werkzeugmaschinenfabriken e.V.
Corneliusstraße 4 · 60325 Frankfurt am Main
Tel. +49 69 756081-0 · Fax +49 69 756081-74
metav@vdw.de · www.metav.de
www.metav.de
International fair for manufacturing
technology and automation
Rapid.Tech goes METAV
1-2014 heat processing
31

Handbook
NEWS Media
of
Aluminium recycling
www.vulkan-verlag.de
Mechanical Preparation | Metallurgical Processing | Heat
treatment
the Handbook has proven to be helpful to plant designers and operators
for engineering and production of aluminium recycling plants. the
book deals with aluminium as material and its recovery from bauxite,
the various process steps and procedures, melting and casting plants,
metal treatment facilities, provisions and equipment for environmental
control and workforce safety, cold and hot recycling of aluminium including
scrap preparation and remelting, operation and plant management.
Due to more and more stringent regulations for environmental control
and fuel efficiency as well as quality requirements sections about salt
slag recycling, oxy-fuel heating and heat treatment processes are now incorporated
in the new edition. the reader is thus provided with a detailed
overview of the technology of aluminium recycling.
editor: C. Schmitz
2 nd edition 2013, approx. 500 pages, hardcover
Vulkan-Verlag GmbH, Huyssenallee 52-56, 45128 Essen
knowledge for tHe
future
order now by fax: +49 201 / 82002-34 or send in a letter
Deutscher Industrieverlag GmbH | Arnulfstr. 124 | 80636 München
Yes, I place a firm order for the technical book. Please send
— copies of Handbook of Aluminium Recycling 2nd edition 2013
(ISBN: 978-3-8027-2970-6 ) at the price of € 130,- (plus postage and packing)
Company/institution
first name and surname of recipient
Street/P.o. Box, No.
Country, Postcode, town
reply / Antwort
Vulkan Verlag GmbH
Versandbuchhandlung
Postfach 10 39 62
45039 Essen
GERMANY
Phone
e-mail
Line of business
fax
Please note: According to German law this request may be withdrawn within 14 days after order date in writing
to Vulkan Verlag GmbH, Versandbuchhandlung, Postfach 10 39 62, 45039 essen, Germany.
Date, signature
PAHBAr2013
In order to accomplish your request and for communication purposes your personal data are being recorded and stored.
It is
32
approved that this data may also be used in commercial ways by mail, by phone, by fax, by email, none.
heat processing 1-2014
this approval may be withdrawn at any time.
✘

Heat Treatment
REPORTS
Carbon control in PM sintering
by Eduard Hryha, Gerd Waning, Lars Nyborg, Akin Malas, Soren Wiberg, Sigurd Berg
Challenges in controlling carbon potential during sintering of steel powder have been discussed in many experimental and
theoretical studies. The main issues lie within the complex thermodynamics and kinetics of processing atmosphere chemistry
in continuous sintering furnaces. Although many models have tried to address the problem, many of these have rarely come
to reality and become an industrial practice. The purpose of this article is to summarize these discussions and investigate the
interaction of the atmosphere constituents with the sintered compact within a sintering furnace. Considering an industrial
practice perspective, the paper ensures the PM Industry with a fresh new look into the understanding of the furnace operations
and provides recommendations to improve the control of the furnace conditions. As an example, existing furnace installation
utilizing Linde Sinterflex ® technology allows monitoring and/or controlling the furnace atmosphere. This article describes the
reduction of oxides and carbon potentials to enable optimisation of the production parameters.
Sintering of high-performance PM parts inevitably implies
both high-quality starting powder and robust processes.
If the first one is well-ensured by both manufacturers
and component producers, the process itself and its control
are the vital factors determining the final performance of the
sintered component produced. When it comes to controlling
the sintering process, there are a number of inter-linked
parameters that have to be adjusted at the same time, such as
the temperature profile, the furnace load, the belt speed, the
sintering atmosphere composition, the flow etc. But while the
furnace parameters connected to its productivity are rather
easy to determine and control, the sintering atmosphere is
the most complex parameter to understand and monitor in
spite of the large amount of studies already performed on
the subject.
SINTERING ATMOSPHERES
The sintering atmosphere is the single gas or mixture of the
gases with the composition that ensures a protective environment
and/or supports useful interactions with the compact.
The choice of the gas components must take into account
possible reactions between the gases, the sintered material,
the furnace lining and carriers, heating elements etc. Interactions
in the furnace depend on the temperature and pressure
and are numerous due to the high activity of the gases used in
commercial production, such as H 2 , H 2 O, CO, CO 2 , O 2 , N 2 , etc.
Therefore, the sintering atmosphere of a defined composition
can be neutral, reducing or oxidizing, carburizing or decarburizing,
depending on the material used and temperature [1]. In
continuous belt sintering furnaces, a sintering atmosphere of
almost constant composition flows through whole furnace,
starting from the cooling zone to the heating/delubrication
zone (Fig.1). Hence, different functions are expected from the
same processing atmosphere depending on the temperature
zone, e.g. slightly carburizing in the cooling zone, neutral in
the sintering zone and reducing in the heating zone, making
sintering furnace atmospheres really challenging in terms
of composition optimization and control. The main functions
of the sintering atmospheres in different temperature
zones and their interaction with sintering material are shortly
described below.
Preheating or delubrication zone
During heating of the compacts, the first critical step is delubrication
during which admixed lubricant is removed and
compacts are preheated. At the beginning of this phase
the lubricant inside the compact is heated up to its melting
temperature. Molten lubricant can rinse out of the compact.
Further increasing of temperature leads to evaporation and
decomposition of the lubricant. Especially in continuous operated
furnaces like belt furnaces a gas is added to the atmosphere
to prevent the furnace from sooting. Here for example
an understoichiometrically burnt propane-air mixture with
a certain content of carbon dioxide and steam as oxidising
components may be used. Using a dry astmosphere helps
purging out gaseous residuals. Burning off the lubricant leads
to a significant oxidation of the base powder which is not a
problem during sintering of iron-carbon PM steels, as iron
oxides are easily reduced at elevated temperatures. However,
this technique should be used quite carefully during sintering
of alloyed PM grades due to the risk of formation of a high
amount of stable oxides, which are difficult to reduce in under
1-2014 heat processing
33

REPORTS
Heat Treatment
temperature [3, 4]. Almost all the lubricant is removed during
heating to about 450 °C [3, 4].
Fig. 1: The atmosphere functions in a sintering furnace
Fig. 2: SE images of particles of powder Fe-1.8Cr showing morphology and
distribution of particulate features on the powder surface, from [5]
commonly used industrial sintering conditions. In the case of
high-performance PM steels, decomposed lubricant is mainly
purged out during heating with a dry atmosphere. The most
commonly used lubricants are complex organic compounds,
based on ethylene bis stearamide (EBS), the decomposition
of which, depending on availability of oxidizing atmosphere
components, leads to the production of water vapour, hydrogen,
hydrocarbons and carbon oxides. The outcoming atmosphere
composition may lead to the oxidation of the material.
Therefore, a fast removal of the products of lubricant
decomposition and prevention of their penetration into the
high-temperature zone has to be provided. A combination of
the a zirconia oxygen probe and a CO 2 sensor allows careful
monitoring of different stages of the process [2]. The oxygen
sensor indicates the beginning of lubricant evaporation and
decomposition into hydrocarbons, and the CO 2 sensor allows
monitoring the further lubricant decomposition process. The
largest part of the lubricant is removed by evaporation and/
or decomposition into heavy hydrocarbons, starting after
~270 °C with a maximum at 410 °C, independent of the processing
atmosphere’s composition/purity and the processing
Heating zone
During the further heating, the second and probably the most
important stage during the sintering process is the reduction
of the surface oxides. These oxides comprise diffusion barriers
that hamper formation of sinter necks between the metal
particles. As the surface oxide is heterogeneous (see Fig. 2
and 3) its reduction is taking place in a number of stages [5]
that have to be taken into account during process adjustment
and control. Surface analysis of pre-alloyed powder [6] indicates
that the surface oxide is composed of a homogeneous
iron oxide (Fe 2 O 3 ) layer with a thickness of around 6 nm, with
the presence of spherical particulates with an average size of
around 200 nm, formed by Cr-Mn-Si-Fe oxides (see Fig. 3). The
total coverage of the powder surface by particulate oxides is
only around 5 %. Hence, the iron oxide layer, which is easy to
reduce, contains around 45 % of the total oxygen content in
the powder. The residual 55 % of the oxygen is in the complex
internal oxides and particulate oxides on the surface, where
the portion of internal oxides is dominant. The sintering of
such a powder does not have to face difficulties, as around
95 % of the surface is covered by easily-reducible iron oxide
(see Fig. 3). Therefore, when facing difficulties with the sintering
of such a pre-alloyed steel powder, the problem is basically
never the powder itself but changes in the surface oxide’s
characteristics during sintering due to improper conditions
applied, especially during the heating stage.
Surface oxides can be reduced by a number of reactions
between the metal powder and components of the sintering
atmosphere as well as carbon, admixed to the compact.
The first reaction that has to be considered is the dissociation
of oxides:
Dissociation of even iron oxide requires very low oxygen
partial pressures (around 10-15 bar at 1,000 °C [1]). For this
reason, additional reducing agents are used. These can be
part of the sintering atmosphere, e.g. hydrogen and carbon
monoxide, or admixed in the compact as carbon (graphite).
The reduction by hydrogen:
is of huge importance as an iron oxide layer, which contains
about 50 % of the total oxygen content in the powder, can
be removed at low temperature – in the range of 400-550 °C
in dependence on the base powder and heating rate [6].
After the Boudouard equilibrium (~720 °C, see Fig. 4) the
carbothermal reduction becomes the dominant reduction
34 heat processing 1-2014

Heat Treatment
REPORTS
Fig. 3: Model of the oxides distribution
in water atomised lowalloyed
Cr-Mn-steel powder,
from [6]
Fig. 4: Standard free energy changes for the reactions between the active
gases in the sintering atmosphere, HSC Chemistry 7.0
mechanism. There are two plausible mechanisms, the first of
which is the reaction of the surface oxides with the graphite,
which is present on the powder surface and in direct contact
with oxide:
stage of reduction by carbon starts after 720 °C – this is an
indirect carbothermal reduction, where the carbon monoxide
is the reducing agent. The model reaction in this case is:
The problem with this mechanism is that the number
of direct contacts between graphite and base powder is
rather limited. The second mechanism is connected with the
improvement of atmosphere purity by reaction of graphite
with oxygen and water vapour inside the pore by reactions:
The sintering of steel compact in the hydrogen-containing
atmosphere leads to complex interactions between active
gases. A very important interaction takes place in this mixture
between CO, CO 2 , H 2 and H 2 O at high temperatures according
to the so called water reaction:
(thermodynamically favourable after ~680 °C) as well as
and
(thermodynamically favourable after ~720 °C), see Fig. 4. This
means that the local conditions inside the pore – the microclimate
– are significantly improved, creating favourable conditions
for oxide reduction inside the pore. In CO-containing
atmospheres or even inert atmospheres after generation
of carbon monoxide by direct carbothermal reduction, the
second and more intensive (due to the presence of gas phase)
Hence, at given temperature in an atmosphere containing
both reducing gases CO and H 2 , the equilibrium partial
pressures for the constituents in the high-temperature zone
of the sintering furnace cannot be changed independently
from one another. This reaction strongly depends on the temperature
and results in more favourable conditions for stable
oxides reduction after ~820 °C (Fig. 4). It also emphasizes the
importance of the hydrogen content, increasing of which
shifts equilibrium to more reducing conditions. The water
reaction also indicates that, from a thermodynamic point of
view, there is no difference which atmosphere component
is being measured – oxygen partial pressure, dew-point (H 2 /
H 2 O ratio) or CO/CO 2 ratio – for proper atmosphere control [1].
1-2014 heat processing
35

REPORTS
Heat Treatment
Fig. 5: Fracture surface of Fe-1.8Cr-0.5C compacts after delubrication at 450 °C (left) and
heating up to 1,000 °C (right), indicating graphite presence until sintering temperature
atmosphere and therefore of the accelerated
removal of products of the oxide reduction.
This leads to the better “microclimate” conditions
inside the pores that are more reducing
than in the core. A fully ferritic microstructure
in the centre of the same compact clearly indicates
that the iron oxide layer is still present,
covering the powder particles. The effect of
atmosphere replenishment inside the compact
is very important for obtaining a homogeneous
degree of sintering throughout the compact,
as the reduction of the iron oxide layer
and consequently the onset of inter-particle
neck development starts at different temperatures
through the compact cross-section. It
is also important to emphasize again that –
even if the carbothermal reduction by admixed
graphite is thermodynamically possible after
the Boudouard equilibrium at ~720 °C (see
Fig. 4) – experiments show that kinetically this
reduction is effective only after ~900 °C. When
the sintering temperature is reached, almost
all the graphite is dissolved in the steel matrix.
Fig. 6: Microstructure of Fe-1.8Cr-0.5C compacts, heated in N 2 /10 % H 2 atmosphere to
900 °C (left) and 1,000 °C (right), showing extent of carbon dissolution, from [5]
When it comes to processing atmospheres interactions in
sintered steels, there is an important difference in comparison
with solid steels when it comes to the carbon distribution and
thus its activity during the process. During the whole heating
stage and up to the sintering temperature, carbon is present
in the pores as graphite particles (see Fig. 5). Therefore, the
carbon activity the during the entire heating cycle is equal to
1, meaning that carbon potential during the heating stage is
not as important as the reducing potential. The time during
which graphite particles will stay in the pores depends on
the graphite particles’ size, the heating rate and the reducing
potential of the atmosphere. Graphite can dissolve in
the steel matrix only after α → γ transformation and only
after the surface iron oxide layer is reduced. Consequently,
by following the microstructure development with the temperature,
the efficiency of the iron oxide layer reduction in
different parts of the components can be traced (see Fig. 6).
In reducing atmospheres, the iron oxide layer will be reduced
at low temperatures (350-500 °C) and so carbon will start to
dissolve after ferrite → austenite transformation. A fully pearlitic
microstructure close to the component surface (Fig. 6) is
a consequence of the improved interaction with the furnace
Sintering zone
Due to the intensive mass-transfer at high
temperatures, dwell at sintering temperature
is aimed at growing significant inter-particle
necks to enhance their strength and rounding
of pores in order to improve static and
dynamic properties of the component. The
composition and purity of the sintering atmosphere then have
to be designed to provide sufficient reducing potential, to
remove residual oxides (or as minimum to prevent formation
of thermodynamically stable oxides). The reducing potential
of the atmosphere can be easily calculated knowing compact
composition and sintering atmosphere composition [6]. At
the same time, all of the graphite is already dissolved in the
steel matrix, meaning that now carbon content in the material
will be solely determined by the carbon potential of the
sintering atmosphere. Taking into account high surface area
available for reaction that is about 10,000 times larger than
the surface area of dense material of the same weight, and the
high temperature, meaning significant carbon diffusion rate,
the carbon potential of the sintering atmosphere solely determines
extent of carbon loss or gain, both being detrimental
for the mechanical properties of the material. Consequently,
the most important parameter of the processing atmosphere
at sintering temperature is the carbon potential that has to be
neutral to keep designed chemical composition and therefore
final structure of the component. In an ideal case, sintering
atmospheres are designed to be neutral at sintering temperature,
but slightly carburising at lower temperatures.
36 heat processing 1-2014

Heat Treatment
REPORTS
The main decarburizing reactions occur due to the interaction
of dissolved carbon on the pore surface with the oxygen
or water vapour in the pores according to the reactions: C +
1/2O 2 CO and C+H 2 O → CO+H 2 , the second one being more
intensive. As decarburizing by water vapour is the most intensive,
carbon activity of the sintering atmosphere is strongly
dependent on its dew point. In badly controlled hydrogencontaining
sintering atmospheres, considerable decarburization
can occur (Fig. 7). At the same time, controlled dry N 2 /
H 2 mixes with up to 10 % of hydrogen have shown to be
neutral and reliable due to low dew point values, i.e. high and
favourable H 2 /H 2 O ratios.
Carbon restoration zone
This is the old, traditional name of the first cooling zone, following
the high-temperature sintering zone, aimed at partly
restoring carbon losses that components can possess after
the sintering zone. Nowadays, a controlled sintering process
means no carbon losses in the sintering zone and therefore
the aim of the zone is to provide further surface carburisation
in order to produce compressive stresses in the component
surface, whereby improved dynamic mechanical properties
can be obtained. Hence, a more accurate definition of the
zone is the “surface carburization zone”. The idea behind
this is that carbon potential in the same sintering atmosphere
increases as temperature decreases (Fig. 7). Besides
carbon monoxide addition (from methanol decomposition,
for example) propane addition is effective to increase both
carbon and reducing potentials of the processing atmosphere,
owing to the reaction: C 3 H 8 + 3H 2 O → 3CO + 7H 2 .
The carbon potential of the atmosphere in this zone could
be calculated by using the dew-point and the oxygen or carbon
dioxide partial pressure measured at furnace (sampling)
temperature. The carbon potential must be further adjusted
to the required level by logical controllers adding enrichment
gases and/or regulating flow, respectively. Sinterflex® is one
of the carbon-potential control technologies designed for
robust sintering processes [7, 8].
Fig. 7: Carbon activity in AstCrM+0.4C N 2 /10 % H 2 sintering
Cooling zone
The main aim of the high-cooling zone is to provide cooling
rates required to form the designed microstructures after sintering.
A variety of microstructures can be obtained for alloyed
PM steels by applying different cooling rates (Fig. 8). Hence,
a wide range of mechanical properties can be obtained for
the same material. Therefore, in order to reach the required
mechanical performance of the PM component, the cooling
rate is the most important parameter to control in the cooling
zone. As soon as the desired microstructure is formed, no further
oxidation is allowed. Thus, the reducing potential of the
atmosphere has to be controlled in this zone, by monitoring
the dew-point or the oxygen partial pressure.
Sinterflex ® control system
As described above, there are a number of methods to
control the carbon potential in the sintering zone of a furnace
after adding the minimum amount of CO to the N 2 /
H 2 furnace atmosphere. The options and restrictions of
those methods are mentioned below:
Fig. 8: Phase composition for AstCrM+0.4C (Fe-3Cr-0.5Mo-0.4C) after cooling with 1 K/min (left) and 3 K/min (right), JMatPro6.2
1-2014 heat processing
37

REPORTS
Heat Treatment
Fig. 9: Calculated values from an O-probe at 1,120 °C
with different CO additions to the N 2 /10H 2 , at
two C-levels of the steel
Fig. 10: Megamet test setup and furnace schematic
■■
■■
■■
measure the dew point and the CO and calculate the reaction
CO+H 2 → C+H 2 O. The restriction is the accuracy and
reliability of a dew point meter in continuous operation in
a carbon rich atmosphere;
measure the CO 2 and CO content in the furnace atmosphere,
using the IR principle, and calculate the reaction
2CO → C+CO 2 . The restriction to this method would be
that the very low CO 2 values in equilibrium are on the
lower border of the sensitivity that the measuring device
can bring;
measure the concentration of the oxygen-partial-pressure
in the furnace atmosphere, using a zirconia oxygen probe
heated to the equal temperature as the furnace, and calculate
the reaction CO → C+½O 2 . Since the restrictions to
this method are small in terms of measuring sensitivity and
reliability (c.f. Fig. 9), it has been chosen for further industrial
exploration under the name Sinterflex ® . This method
is also common practice in the hardening industry as well
as the use of enrichment gases such as propane added
to the carrier gas and the flow rate of it is controlled by a
logical controller (PLC).
Case study: Carbon control in an MIM high-temperature
pusher sintering furnace [9]
Megamet Solid Metals (Earth City, Missouri, USA) applied the
Sinterflex ® carbon control system for sintering of non-stainlesssteel
MIM parts, utilising a high-temperature pusher-type
furnace. Due to the high temperature sintering process, difficulties
in carbon control in sintering furnace atmospheres
are amplified in MIM. Megamet had been experiencing decarburization
of parts with final part specification of 0.4-0.6 %
carbon. Each ceramic boat was loaded with at least 12 parts
and they had been experiencing variation in part carbon
content among parts on a given boat from 0.1 % to 0.4 % C.
Over 200 sintered parts were tested for carbon content in
Megamet’s analytical lab. These results were correlated to the
set points and realised carbon potential recorded by Linde’s
carbon potential control system. The furnace and the setup
of the Linde carbon control system are shown in Fig. 10.
The baseline data had indicated that the sintered parts were
typically decarburised to varying degrees in virtually every
batch (boat) for the subject parts sintered without the use
of a carbon control system (Fig.11).
The microstructure of the parts sintered under the baseline
atmosphere [8, 9] indicated considerable decarburization on
the surface and in the core. Thus tests were then run with
the furnace atmosphere controlled and modified with the
Sinterflex® carbon control system. The carbon potential of
the furnace atmosphere was calculated knowing the amount
of oxygen and CO in the furnace as well as temperature. The
result was that uniform carbon content of around 0.5 % C
(±0.05 % C) in the parts was achieved (see Fig.11, right).The
microstructures of products sintered with the carbon control
system indicated that the decarburization has been significantly
reduced at the surface and almost eliminated in the
core of the parts [8, 9].
CONCLUSION
Careful control of both oxygen and carbon potentials in the
sintering atmosphere during the whole sintering process is of
vital importance for obtaining high-performance parts with
low scattering in the final properties. The reducing potential
of the sintering atmosphere is the decisive parameter during
the heating stage, as it determines surface oxide reduction
and therefore inter-particle neck development and strength.
During sintering, the carbon potential has to be controlled in
order to provide sufficient reducing conditions for reduction
of residues of thermodynamically stable oxides and, the most
38 heat processing 1-2014

Heat Treatment
REPORTS
Fig. 11: Carbon content in parts without C-potential control (left) and using the Sinterflex ® carbon control system (right)
important, to prevent decarburisation of steel. If surface carburisation
is aimed to be achieved in the final parts, carbon
control is of vital importance for providing the required carbon
potential of the sintering atmosphere in the carburisation/
cooling zone. The Linde carbon control system Sinterflex ® has
been demonstrated to successfully control the carbon potential
of the sintering atmosphere in the sampled area. With the
use of the Linde carbon control system, it was possible to
establish and sustain the furnace atmosphere conditions for
three different sintered MIM parts so that the parts’ carbon
contents could be maintained in the 0.4-0.6 % C specification
window. This control was not repeatable without the use
of the Linde carbon control system. The carbon potential
measured in the highest temperature zone can be used to
direct the introduction of trim gases in order to optimise the
process and improve part quality and consistency.
LITERATURE
AUTHORS
Eduard Hryha
Chalmers University of Technology
Gothenburg, Sweden
Tel.: +46 (0) 317 / 7227-41
hryha@chalmers.se
Gerd Waning
Linde AG
Bielefeld, Germany
Tel.: +49 (0) 521 / 3034-127
gerd.waning@de.linde-gas.com
Lars Nyborg
Chalmers University of Technology
Gothenburg, Sweden
Tel.: +46 (0) 317 / 7212-57
lars.nyborg@chalmers.se
[1] Hryha, E.; Dudrova, E.; Nyborg, L.: J. Mater. Proc. Technology,
2012, Vol. 212, pp. 977-987
[2] Hryha, E.; Nyborg, L.: Acta Metallurgica Slovaca, 2012, Vol. 18, No. 2
[3] Hryha, E.; Karamchedu, S.; Nyborg, L.: Proc. of EURO PM2011,
Barcelona, Vol. 3, pp .105-110
[4] Karamchedu, S.; Hryha, E.; Nyborg, L.: Powder Metallurgy Progress,
2011, Vol. 11, pp. 90-96
[5] Hryha, E.; Nyborg, L.: Proc. of World PM2010, Florence, Italy, Vol.
2, pp. 268-275
[6] Hryha, E. et al.: Applied Surf. Sci., 2010, Vol. 256, pp. 3946-3961
[7] “Furnace atmospheres No. 8. Sintering of steels”, Linde Gas, 2011
[8] Malas, A.: Proc. of EURO PM2011, Barcelona, Spain, Vol. 3 , pp. 117-122
[9] Palermo, T.; Malas, A.: Presented in PowderMet 2012, Nashville,
Tennessee, USA
Akin Malas
Linde AG
Unterschleißheim, Germany
Tel.: +49 (0) 89 / 31001-5549
akin.malas@linde.com
Soren Wiberg
AGA Gas AB
Lidingö, Sweden
Tel.: +46 (0) 87069587
soren.wiberg@se.aga.com
Sigurd Berg
Höganäs AB
Höganäs, Sweden
Tel.: +46 (0) 423 / 380-00
sigurd.berg@höganäs.com
First published by Maney Publishing on behalf of the Institute of Materials, Minerals and Mining in the journal Powder Metallurgy No. 1, Vol. 56, 2013,
page 5, see also www.maneyonline.com/pom
1-2014 heat processing
39

REPORTS
Heat Treatment
Gas- and plasmanitriding –
practical aspects in heat
treatment shops
by Gero Walkowiak
Because of its many interesting properties nitriding has taken a high priority in the heat treatment business. When
planning new or additional capacities often the question arises in which nitriding technology to invest. For customers
it is very important to know which technology is most appropriate for their products. Among other facts quality and
economic efficiency influence the choice of the method. In the following chapters gasnitriding and plasmanitriding are
introduced, special features are described and the advantages of each technology are highlighted. The technologies
of gasnitriding and plasmanitriding are presented especially with regard to the practical application in a commercial
heat treatment shop.
schematic
layer
constitution
Gasnitriding is usually carried out in a temperature
range between 480°C to 540°C in most cases in retort
furnaces. The heating of the batch takes place in a
nitrogen atmosphere. To improve the activation of the surface
often a pre-oxidation is performed (temperature range 300°C
to 450°C). After heating up to treatment temperature a gas
mixture that contains ammonia is passed into the furnace.
By decomposition of ammonia on the workpieces active
nitrogen is generated which can diffuse into the surface. A
flow of a fresh gas mixture constantly replaces the dissociated
• oxide layer: Fe 3 O 4 , in case of post oxidation
• compound layer: (Fe 2 N), ´(Fe 4 N)
• diffusion layer: dissolved nitrogen + nitride precipiations
Fig. 1: Schematic structure of a nitride layer
oxide layer 0.5 - 3 µm
compound layer
(5 - 30 µm)
diffusion layer
(0.05 – 0.5 mm)
substrate
ammonia. An even supply of the whole batch with the fresh
gas mixture is ensured by a suitable constructed gas leading
cylinder and a powerful gas circulator.
The generic term gasnitriding also includes the method
gasnitrocarburising (optional with post oxidation). In case of
nitrocarburising besides the ammonia a carbon supplying
gas/additive is added to the process gas. With 520°C - 590°C
the temperature of nitrocarburising is higher than in the
case of gasnitriding. The post-oxidation (often with steam
as process gas) produces an iron oxide (magnetite) which
generates a passivation of the compound layer and significantly
improves the corrosion resistance. Due to the intake
of nitrogen different zones are formed in the surface area of
the workpiece (Fig. 1).
Nearest to the surface a compound layer is formed which
can consist of ɛ- and/or ɣ´-nitrides, depending on the nitrogen
content of the compound layer. Both are intermetallic
compounds. The formation of the ɛ-layer is favored by
the additional intake of carbon in case of nitrocarburising.
The thickness of the compound layer can be varied usually
between 0 and 30 µm, depending on the requirements and
the applied technology. The thickness is measured in a nital
etched cross section where the compound layer appears
as a white layer. Alternatively the examination with GDOES
(Glow Discharge Optical Emission Spectroscopy) is possible.
In case of a post-oxidation a magnetite layer (Fe 3 O 4 - 0.5 to
3 µm) is formed on top of the compound layer.
40 heat processing 1-2014

Heat Treatment
REPORTS
Below the compound
layer the “diffusion
layer“ is formed.
It consists of dissolved
nitrogen and nitride
precipitates. Hardness
and hardness profile
in the diffusion layer
are mainly determined
by the content of the
alloying elements which
form hard nitrides (for
example Cr, Al). The
depth of the diffusion
layer is usually in the
range between 0.05 and
0.8 mm.
a) b)
+
- ion
+ +
workpiece
N
N
N
N
FeN
Fe 2 N
Fe 3 N
Fe 4 N
Fe
Fe
FeN
reaction and nitriding take place
on the surface of the workpiece
N
atom
Fig. 2: Mechanism of covering in plasmanitriding
furnace wall
- ion
+ +
workpiece
N
N
N
N
X
X
X
X
FeN
Fe 2 N
Fe 3 N
Fe 4 N
Fe
solid masking
Fe
FeN
Reaction takes place on the
surface of the solid masking.
Nitriding of the workpiece is
prevented!
N
atom
+
furnace wall
HOW TO INFLUENCE THE LAYER
STRUCTURE
The key parameter that controls the layer structure during
nitriding is the nitriding potential Kn. It is calculated from
the partial pressures of NH 3 , N 2 and H 2 . The higher Kn the
more intense is the nitriding process and the nitrogen
intake. State of the art is to determine the Kn value by
measuring the hydrogen content of the process gas with
a hydrogen sensor and adjusting the Kn by variation of
the fresh gas flows. A further refinement is the additional
measurement and control of the carbon potential [1, 2].
In practice the ratios of the process gas flows NH 3 , N 2 and
C-gas are adjusted. In addition, based on existing experience,
an upper and lower limit of the ammonia flow are
adjusted so that the batch is not put at risk in case of incorrect
measurements. Especially if a high nitriding depth
is desired dissotiated ammonia or hydrogen is added to
reduce the Kn and to reduce or to completely suppress
the growth of the compound layer.
Taking into account the measured Kn the gas flows are
changed by the process-control via mass flow controllers
to achieve the set point Kn value. The process gas amounts
can vary between below 1 m 3 /h NH 3 during controlled
gasnitriding and up to more than 10 m 3 /h NH 3 at nitrocarburising
of batches with a high surface area.
PLASMA
Plasmanitriding is performed in a gas mixture of mainly nitrogen
and hydrogen. If additionally a carbon-supplying gas is
used (CH 4 , CO 2 ) the method is called plasmanitrocarburising.
The process is carried out in an evacuated oven at a pressure
in the range of 0.5 to 5 mbar. The pressure is controlled
by varying the process gas flows and/or the speed of the
vacuum pump. Conventional gas flows are in the range up
to several hundred liters per hour. The gas composition is
adjusted according to the desired results. A high N 2 content
and the addition of a C-supplying gas promotes the formation
of the epsilon compound layer. With decreasing N 2 content in
the gas and increasing H 2 content the formation of a ɣ’- compound
layer is favored and the layer thickness is reduced. Even
a nitriding without compound layer is possible.
In the process a voltage is applied between the furnace
wall and the components (usually in the range between 400
and 600 V). The furnace wall works as anode (positive pole)
and the batch as cathode (negative pole). In this electrical field
a glow discharge with a high degree of ionization (plasma) is
generated around the parts. By the applied voltage the nitrogen
ions are accelerated towards the surface of the workpieces
where they react to nitrogen-rich Iron-nitrides. The decomposition
of these nitrides generates active nitrogen which can
diffuse into the surface (Fig. 2). In addition to the generation
of active nitrogen the glow discharge also contributes to the
Fig. 3: Layout of a pulse-plasmanitriding furnace [3]
1-2014 heat processing
41

REPORTS
Heat Treatment
PLASMANITRIDING IN HOT WALL
FURNACES
To achieve an improvement of the often insufficient temperature
uniformity and a decoupling of the plasma parameters
from the batch temperature, so-called pulse-plasma systems
with a hot wall technique have been developed. The system
consists of a vacuum vessel with external heating and cooling.
In modern furnaces heating and cooling are separated
into three or more zones dependent of the furnace size. The
number of batch thermocouples should be at least as high
as the number of zones. The layout of a pulse plasmanitriding
system is shown in Fig. 3. An advantage of the hot wall
technique is that the plasma parameters can be set according
to the requirements without strongly influencing the
part temperature. The regulation of the batch temperature
is usually done by an adjustment of the wall temperature. A
further advantage is the improved temperature uniformity
in hot wall furnaces caused by a much lower temperature
gradient between batch and wall compared to cold wall
furnaces. Additionally the applied plasma power can be
reduced to a minimum as in many cases the main contribution
to the batch heating is done by the hot wall. The
influence of part geometry and jigging on the component
temperature is distinctly reduced.
Fig. 4: Jigging of small bolts as loose material;
top: side view schematically, bottom: top view
heating of the batch. Since this mechanism takes place only
in areas that are directly exposed to the glow discharge a
nitriding can be prevented by a metallic shielding of areas in
which the nitriding is not desired (Fig. 2). This smart and easy
way of covering is often used in plasmanitriding processes.
PLASMANITRIDING IN COLD WALL
FURNACES
The first plasmanitriding equipment were the so-called
“cold-wall furnaces”. Cold-wall furnaces consist of a vacuum
chamber with a water-cooled wall. A DC voltage or a pulsed
voltage is applied between the furnace wall and the batch.
The plasma power is the only heating source. The component
temperature is controlled by a voltage change and/or
by changing the pulse on/off ratio in systems with pulsed
plasma. This results in a disadvantage of the cold-wall technique:
temperature control and plasma parameters are not
independent. A further disadvantage is a high temperature
gradient in the batch due to distinct temperature differences
between the components and the water cooled wall.
The temperature uniformity in the batch can be improved
by appropriate jigging. However this often requires a lot of
effort and extensive experience of the employees.
GASNITRIDING IN PRACTICE
The following points should be considered when batch
building:
■■
positioning of the components,
■■
even flow through the batch,
■■
maximum surface of the batch.
A big advantage of gasnitriding is that parts may have
contact during nitriding. In the case of point- and linecontacts
usually no differences in the nitriding results can
be observed. A multitude of smaller parts in high quantity
can be nitrided as loose material without loss of quality. If
the parts have larger contact areas the treatment as loose
material is not recommended because in such cases the
layer thickness decreases from the edge to the center of
the contact area. The severity of this effect is very dependent
on roughness and flatness of the components. The
smoother and more even the contact area the higher is the
obstruction of the gas exchange between the components
and the less intense is the nitriding. Thus parts with larger
flat surfaces (covers, washers) are rather jigged separated
in grids or hanging with spacing between the parts.
Each batch should be jigged in a way that guarantees
a uniform gas flow to minimize differences in the gas distribution
in the furnace. In the case of bulk goods or loos
material there should be space between each layer (Fig. 4).
The depth of filling of each layer may not be increased
arbitrarily. The higher the bulk density the lower the depth
42 heat processing 1-2014

Heat Treatment
REPORTS
of each layer should be chosen. Discs, covers and similar
parts should be jigged as separated goods ideally parallel
to the gas flow direction (Fig. 5).
The necessary fresh gas flows depend on the desired
nitriding potential and have to be increased with rising
surface of the components in the furnace. Highest gas
flows – up to over 1 m 3 /h per 10 m 3 batch surface – are
required in case of nitrocarburising with high compound
layer thickness.
PLASMANITRIDING IN PRACTICE
For plasmanitriding the following points have to be considered
in practice:
■■
cold wall or hot wall furnace,
■■
adaptation of plasma parameters to geometry and
specification of the parts,
■■
maximum batch surface taking into account the geometry
and plasma parameters,
■■
adaptation of jigging and plasma parameters,
■■
adaptation of jigging with regard to the best temperature
uniformity,
■■
avoid batch and part areas with not or insufficient glow
discharge,
■■
prevention of uncontrolled hollow cathode formation.
In case of jigging for cold wall furnaces the high temperature
gradient between components and cooled furnace
wall must be compensated by an appropriate positioning
of the parts in the batch. In the outer circles the spacing
between the parts should be smaller than in the centre
of the batch. Heat shields at the edges of each jigging
plate and blind layers at
top and bottom which are
heated up by the plasma
power can be applied to
improve the temperature
uniformity. Fig. 6 shows
a suitable jigging for serial
parts. Parts of very different
geometry should not
be treated in one batch,
especially when the surface
/ volume ratio is significantly
different. If this
is necessary for economic
reasons appropriate jigging
can still lead to satisfying
results (Fig. 7).
The characteristics of the
glow discharge in plasmanitriding
is affected by various
parameters. Most influence
have voltage, pressure, gas
Fig. 5: Jigging of covers (approx. 115 mm diameter x 3 mm
thick) separated in grids
composition and temperature. In both cold and hot wall furnaces
these parameters have to be adapted to the geometry
of the component. It is mandatory to avoid an uncontrolled
hollow cathode formation with subsequent overheating of
the components. This effect is shown in Fig. 8: with increasing
pressure the glow seam (region of high charge density) reaches
into smaller and smaller holes. The range of overlapping glow
seams should be avoided.
In case of plasmanitriding of narrow holes or grooves
a high pressure is necessary to maintain a nitriding inside
Fig. 6: Appropriate jigging for cold-wall plasmanitriding with lower load density in the center;
right: heat shields and blind levels for temperature compensation
1-2014 heat processing
43

REPORTS
Heat Treatment
increasing pressure
cfd >> d
cfd d
cfd 4 mbar
furnace wall (anode)
distance to furnace wall (anode)
Fig. 9: Effect of pressure on voltage profile and glow seam formation
in plasmanitriding
Fig. 10: Plasmanitriding of narrow holes with high treatment
pressure (3.75 mbar)
44 heat processing 1-2014

Heat Treatment
REPORTS
LITERATURE
[1] H.-J. Spies: Controlled Gasnitriding and Nitrocarburising of
Iron Materials, The Heat Treatment Market, 4 (2003), 5-14
[2] Karl-M. Winter, S. Hoja, H. Klümper-Westkamp: Controlled
Nitriding and Nitrocarburizing – State of the Art – European
Conf. on Heat Treatment 2010, Nitriding and Nitrocarburising,
29.-30. April 2010, Aachen, Germany
[3] R. Grün, D. Voigtländer: Kosten- und ressourceneffiziente
Randschicht-wärmebehandlung in der Getriebe- und
Werkzeugindustrie mittels Plasma-Nitrieren – Elektrowärme
International, Heft 2/2009, Juni
[4] G. Walkowiak, M. Magnacca: Nitriding and Related Processes
for Tools and Dies – Applications and Quality Aspects, Proceedings
of the 3 rd int. IFHTSE Conf. on Heat Treatment and
Surface Engineering of Tolls and Dies, 23.-25.3.2011, Wels,
Austria
AUTHOR
Dr. Gero Walkowiak
Bodycote Wärmebehandlung GmbH
Hürth, Germany
Tel.: +49 (0)2233 / 94697-0
gero.walkowiak@bodycote.com
A Company of the PVA
TePla Group
PulsPlasma ® Nitriding for Wear
and Corrosion Protection
• Cost and Resource-effective
• Flexible Plant Concepts
• Variable Nitriding Processes
• Low Temperature Treatments
• Process Combination
More information:
PlaTeG GmbH
Im Westpark 10-12
35435 Wettenberg
Phone:
+ 49 (641) - 6 86 90 490
Mail:
service@plateg.de

International
Trade Fair for
Metallurgy, Machinery,
Plant Technology
and Products
The International
Tube and Pipe
Trade Fair in Russia
International
Trade Fair for
Aluminium and
Non-Ferrous Metals,
Materials, Technologies
and Products
3 – 6 June 2014
Krasnaya Presnya
Moscow, Russia
www.metallurgy-tube-russia.com
In co-operation with
Messe Düsseldorf GmbH
P.O. Box 10 10 06 _ 40001 Düsseldorf _ Germany
Phone +49 (0) 2 11/45 60-77 93 _ Fax +49 (0) 2 11/45 60-77 40
RyfischD@messe-duesseldorf.de
www.messe-duesseldorf.de

Energy Management
REPORTS
Resource savings and energy
efficiency in heat treatment
shops
by Olaf Irretier
During the last years the topic of energy efficiency has taken place in nearly all areas of industrial production. The general
resource and environment protection, the rising energy prices and the aim of process cost reduction release currently
a row of discussions and measures. In the future also the legal national and international regulations have to be taken
into account and lead into further increasing activities concerning energy-efficient arrangements and procedures. The
present contribution treats the different arguments and possibilities of the energy efficiency in heat treatment and
industrial furnace technology and shows practical aspects and measures to its increase.
Energy efficiency improvement, reduction of energy
costs and gas emissions and thereby relieving the
environment: These are the aims of the first European
norm introduced in August, 2009 EN 16001 as well as the
worldwide valid norm ISO 50001 for operational energy
management. Both intend the introduction of an operational
energy management system and define in addition obliging
criteria for producing enterprises.
Thus the worldwide consumption of raw materials has
increased during the last 30 years to the primary power production
about 70 %. Up to 2030 an increase of the worldwide
primary energy consumption compared to 2006 of about
over 45 % is expected (World Energy Outlook in 2008). On
the other hand Germany aims at the decline of the greenhouse
gases for 2012 of about 21 % compared to 1990. Till
2020 even a reduction of about 40 % of the greenhouse
gases should be achieved. The other long term aims were
fixed in 2008 at the G8 summit in Japan with halving the
emissions till 2050 which requires an increase of the energy
efficiency of about 3 % yearly – currently the annual increase
of the energy efficiency is less than 2 %!
It is obvious that the European Union acts and will further
act to increase the efficiency of the energy-intensive processes
in particular. Other demands for the environmentally
compatible design of energy-pursued products (ecological
design directive) were fixed by the directive in 2006 / 23 / of
the EU. For the future the EU has fixed other aims, among
other things the increase of the energy efficiency of about
20 %, the reduction of greenhouse gas emissions of about
20 % and the general support of renewable energy. With the
“New Approach beginning” of the EU (the EU harmonisation,
CE marking, conformance assessment, etc.) only the products
may be brought in trade which correspond to this directive.
Topically the EU commission has provided a suitable study
of the industrial furnaces which contains among other things
also the definition of energy efficiency.
ENERGY BALANCE IN INDUSTRIAL
FURNACE TECHNOLOGY
During every kind of combustion process, a large amount
of CO 2 is produced. 40 % of the industrially used energy is
used for industrial furnaces, corresponding to a cost volume
of about € 30 billion. In spite of energy saving in the last
decades the consumption amounted in 2005 in thermo
process technology of about 270 TWh – an energy potential
to supply Bavaria with energy for one year. Modern
industrial furnaces compared with older ones save about
20 % in the wall insulation, 75 % in exhaust gases and about
60 % in protective gases. The use of other future potentials
allows energy savings of about 10 %.
MEASURES TO INCREASE THE ENERGY
EFFICIENCY IN INDUSTRIAL FURNACES
Concerning the measures to increase energy efficiency
there are many different possibilities which are shown in
Fig. 1 in an overview diagram and in Table 1 in detail.
1-2014 heat processing
47

REPORTS
Energy Management
doors and locks
insulation
burners
energy saving drives
and pumps
Heat recovery
(oilbath, waste gas,
protective gas)
energymanagement
Fig. 1: Measures to increase the energy efficiency
Fig. 2: Picture made with a thermographic camera
The assessment of a more efficient energy use in heat
treatment shops is connected in general also to the question,
how the available warmth, i.e. the energy content
of a component, of an atmosphere or a material can be
transferred by a temperature gradient to another medium
or the surrounding. The problem which is to be solved
is that the available warmth or heat amount arises discontinuously
and is dependent on the time of day or
the season. That’s why a suitable energy management
system helps basically.
Insulation – Thickness and material
High temperature processes have very special requirements
to furnace insulation which have been complied
by optimised application of insulating materials (fibre,
wool, refractories and stones). In the last decades the
reduction of energy consumptions in high temperature
processes was up to 30 %. The quality of the industrial
furnace is substantially influenced by the choice or
combination of the insulants concerning energy consumption,
heating and cooling speed, energy losses,
Table 1: Measures to increase energy efficiency
Primary measures
saving of
gas use of burner waste gases preheating of parts
heating of washing mashines
use of reactive process gases
heating
recuperative heating of burner air
increase of efficiency
current effectiveness of fans increase of efficiency
effectiveness of pumps
increase of efficiency
effectiveness of electric heating
substitution
effectiveness of drives
increase of efficiency
current or/and gas use of energy/heat of quenching bathes heating washing and drying devices
weekend operation
minimizing energy consumption
process optimization
minimizing energy consumption
Secondary measures
external energy use of quenching bathes heating of rooms and water
use of burner gases
heating of rooms and water
48 heat processing 1-2014

Energy Management
REPORTS
Ar1 max. temperature 320 °C
Ar2 max. temperature 220 °C
Ar3 max. temperature 110 °C
Ar1 max. temperature 250 °C
Ar2 max. temperature 260 °C
Ar3 max. temperature 110 °C
Fig. 3: Picture made with a thermographic camera in a chamber
furnace door
Fig. 4: Picture made with a thermographic camera at the internal
door of a chamber furnace
memory warmth and therefore energy efficiency. It is
worth noting that light insulants show a low mechanical
firmness, however, a high insulating property and a
low heat accumulator capacity. The maximum operating
temperatures are relatively low (except in the case of the
ceramic fibre). Heavy insulants are mechanically highly
loadable and have a big heat accumulator capacity and
a lower insulating effect. Pure fibre-insulated furnaces
have, with the same insulating strength, a lower memory
warmth, but a higher radiation loss. Therefore, it depends
on the operating method whether a fibre insulation is
economic or not.
A statement due to insulating design and density of
refractory arrangements can be reached with the help
of pictures of a thermographic camera (Fig. 2 and 3).
The sealing of furnace doors with suitable fibre tape
or regrinding of the furnace door stones is especially
important for a reduction of heat losses. A thermally
critical place are basically the burner flanges. In this area
temperatures from 100 to 200 °C are measured generally.
Also near the insulation of the internal door of chamber
furnaces suitable temperature measurements should be
carried out (Fig. 4).
At high temperature processes the furnace insulation
plays an important role which has been fulfilled during
the last years by the optimised application of insulating
materials (fibre, wool, stones). Thus can be reduced,
for example, by application of microporous insulating
boards (0,025 W/mK) as rare side insulation, the furnace
wall losses about 20 % which corresponds to a decrease
of external furnace wall temperature of about 10 °C. The
pay back times are appr. 3-5 years.
Burner Technology
The cost effectiveness and efficiency of a heat treatment
process depends in particular on the energy consumption
per components or weight of the components. Modern
industrial furnaces are equipped with recuperative
or regenerative gas burners. Currently used gas burners
have integrated recuperators which reach efficiencies from
about 70 % under optimum circumstances. Regenerative
burners achieve theoretically 85 % efficiency and more
(Fig. 5). More aspects of burner technology in energy saving
concepts are explained in several other reports.
Fig. 5: Recuperative gas burner (source: Noxmat)
1-2014 heat processing
49

REPORTS
Energy Management
8
3,0
Verbesserung improvement Wirkungsgrad
of efficiency
[abs. %]
6
4
2
Amortisationszeit
pay back time
Verbesserung
improvement
Wirkungsgrad
of efficieny
2,5
2,0
1,5
statische static Amortisationszeit
payback time
[Jahre] [years]
0
1,0
0 5 10 15 20 25
Motornennleistung motor power [kW]
Fig. 6: Efficiency improvement EFF of electric drives (source: source: Aichelin) Aichelin
Fig. 7: Top current management
Drives and Power Management
In addition the use of drives and engines of higher energy
efficiency class which are moved in connection with future
maintenance and servicing makes sense. The pay back
times for this parts are at appr. 1-3 years (Fig. 6).
For many years the energy-saving by using energy management
systems is discussed very intensively. For short time
running thermal processes of a quantity production a suitable
load or top current management (Fig. 7) energetically may
be absolutely sensible and be connected with a high cost
effect. Long term carburizing processes e.g. in heat treatment
shops gives only low possibility of the chronologically
adaptable creation.
In addition the weekend circuit (with loads in the furnace),
i.e. a reduction of the furnace temperature, for example,
500 °C instead of temperatures above 900 °C lead
to a reduction of wall losses of about 20 % (protective
gased furnace) or 50 % (non-protective gased furnace). To
carry out an evaluation, a suitable capture of the energy
consumption is necessary which is to be compared to
increased servicing and wear costs.
exhaust gas and
air 300 C
exhaust air
exhaust gas /
air heat exchanger
fresh air
150 C
washing machine
heating, drying
Fig. 8: Waste heat recovery (example: furnace exhaust gases) for heating and drying of a
washing arrangement
Heat Recovery
Heating of Washing Machines
For heating of washing machines basically
burner exhaust gases as well as the use of
the heat potential of quenching baths can
be used. The energetic use of burner exhaust
gases (exhaust gas temperature before heat
exchanger higher than 300 °C / after heat
exchanger lower than 150 °C) which can be
used about bypass and water heat exchanger
for the heating of cleaning facilities usually
amortise after 4-6 years. For heating of washing
water in washing machines a temperature
difference is required by at least 15 K.
e.g., oil bath temperature 80 °C, i.e. heat of
the water on max. 65 °C is possible.
The heating of a washing machine
(60-80 °C) or of a complementary component
drying after the cleaning process can
occur, e.g., through waste heat utilisation
50 heat processing 1-2014

Energy Management
REPORTS
from quenching baths, the rejected heat processes or
the burner exhaust gases over heat exchanger (Fig. 8).
With waste heat utilisation from the quenching bath
temperature differences should be given between oil
bath and cleaning bath from higher than 20 °C. The
measure entails respected pay back times of 3-5 years.
When using waste of oil baths for the drying (with or
without vapour condenser) in cleaning arrangements,
pay back times of also 3-5 years are to be expected
for these measures (Fig. 9).
The following example shows that the economic
efficiency of these measures can be at about 3-5 years:
Burner exhaust gas with temperatures from up to
450 °C are supplied about exhaust gas-collective
channel of the high temperature furnace over heat
exchanger of the washing machine (Fig. 10). The saving
of the burner gas can be in such a case at about
€ 5,000 per year.
Drying
In case of using waste heat of oil baths for the drying
(with or without swath condenser, see Fig. 11) in
pusher type furnaces which have an annual coolant
need of about 10,000 to 20,000 m³ an energy
conservation of about 10-20 kW is possible. This
corresponds to a pay back period of 3 years.
Due to an example of a screw factory is the
usage of distiller’s exhaust gases and waste gases
for drying in the washing machine an economically
efficient measure: The energy conservation is up to
50 kW, which corresponds to a cost saving of about
€ 20,000 (pay back of approx. 2-3 years).
oil
80 °C
room heating
heat exchanger
60 °C
washing
machine
heating, drying
Fig. 9: Waste heat recovery (example: oil bath cooling) for heating of rooms or
washing machines
Fig.10: Waste heat recovery of
burner gas for heating
of the washing machine
(source: Aichelin)
Building Tempering
To heat a building a lot of possible heat energy suppliers
described in this article can be used. It has to
be noted that in special periods the warm potential
cannot be used (summer). Moreover, a cooperation
with the TGA is necessary.
GUIDELINE ENERGY EFFICIENCY
To be able to value the situation concerning energy
efficiency in the production process, all available
operational energy data should be determined first.
The determination should be composed of the present
consumption data of all furnace arrangements
as well as of the data to peripheral arrangements
in the heat treatment shop (gas, power and water
consumption).
In addition the responsible staff are included at the
beginning of the project, they are familiarized with figures
and values and informed about the intention of an energetic
optimisation.
hardening
oil
chiller
add. chiller oil/air
Fig. 11: Waste heat recovery of oil bath for drying
After collecting the different energy data the possible
weak points of the process are examined. These are
depending on the kind of the location and on the available
furnace arrangements. Weak points can appear where
energy is used or can escape uncontrollably, e.g. in „heat
drying zone
exhaust air
1-2014 heat processing
51

REPORTS
Energy Management
bridges“ of the furnaces like doors and lids, flanges, corners
and connecting parts. On the basis of the numerical values
which are determined in the analysis realizable measures
are suggested to increase the energy efficiency.
The expiry of the energy efficiency analysis:
1. Problem description, objective, demarcation,
2. Overview with information of the furnace programme
and heat treatment processes,
3. Collecting of ground plans of the company,
4. Listing of the heat-treated amounts and loads, estimated
due to days, weeks and months,
5. Arrangement of technical data of the furnaces,
6. Sighting of maintenance and installation plans for
electricity, gas, cooling, water,
7. Listing of the relevant consumers in energy type or
energy source (for example electricity and water),
8. Arrangement of available data of single consumption
and performance measurements,
9. Listing of received energy sources with calculations
and amounts of the last years,
10. Sighting of the technical documents about waste
disposal plants (waste water, exhaust air, rubbish).
Afterwards a possible measure plan is suggested and
conclusions for the improvement of the operational
energy situation can be drawn. Basically there should
be made a distinction between the structural, organizational
and technical measures. Initial rough cost overviews
for the suggested optimisation should be compiled
and be discussed.
CONCLUSION
The importance of energy efficiency has won increasingly
in industrial processes in the past. The possibilities of the
efficiency increases arise on one hand from the optimisation
of single processes, on the other hand from the comprehensive
consideration and improvement of chained
process and manufacturing procedures.
Hence, the target consists in grasping cross-process
material and energy flows, in balancing and in using the
technical and economic possibilities of the energy conservation
by e.g. shortening of process times, energy storage,
waste heat utilisation or energy recovery. Besides, it is worth
not only to understand the heat treatment processes but
also the cooling processes and to realize suitable strategies
taking into account the technical feasibility and the
observance of the sets of rules and demands relevant for
the environment. Comprehensive approaches of the thermal
processes taking into account all dimensions of influence
are essential and allow finally technically feasible and
commercially interesting solutions on the subject “energy
efficiency”. Here it is a matter to recognise the potentials
from heat treatment, furnace construction, heating technology
and cooling technology across the systems. There
are possibilities enough!
The examination and realization of energy-efficient
measures in hardening shops compellingly requires a cooperation
of the departments of machine and investment
technology and the hardening shop itself. The essential
steps of a suitable analysis to the energy efficiency are:
■■
■■
■■
■■
Stock-taking,
Weak point analysis,
Technical assessment,
Plan of measures and economic efficiency.
Due to the analysis some measures are recommended
which should be realized subsequently:
■■
Elimination of the weak points and energy losses,
■■
Implementing of an energy efficiency concept and an
enterprise-internal energy policy.
With the implementation of future measures it is important
to consider qualitative and organizational aspects, i.e. the
workflow in the company must be performed reliably and
undisturbed.
In cooperation with measures relevant for environment
and for energy also the positive effects on employees
due to security, health and comfort have to be considered
which increase the motivation of the employees to
energy-conscious thinking and acting and which support
the conveyance of the energy-consciousness to suppliers
and customers.
LITERATURE
[1] Beneke et al.: VDMA/TPT: Seminar Energieeffizienz für
Thermprozessanlagen, 2009
AUTHOR
Dr.-Ing. Olaf Irretier
Industrieberatung für Wärmebehandlungstechnik
IBW Dr. Irretier
Kleve, Germany
Tel.: + 49 (0) 2821 / 7153-948
olaf.irretier@ibw-irretier.de
52 heat processing 1-2014

Induction Technology
REPORTS
Inductive hardening of ring
gears and pinions
by Marcus Nuding, Christian Krause
Because of the expanding demand for energy, time and cost savings, and in terms of environmentally conscious manufacturing
processes, SDF® (Simultaneous Dual Frequency) induction heating process for close contour hardening of ring
gears and pinions is presented. With this low-distortion hardening process, subsequent hard machining steps such as
straightening, grinding or lapping can be reduced or completely eliminated. This results in large savings of energy and
especially time and costs.
Ring gears and pinions (Fig. 1) are components of
bevel gears. Their task is transmission of torques
between the gearbox and the drive wheels. There
are three different basic profiles: straight toothed, helical
toothed and spiral bevel gears (Fig. 2) [1]. The spiral
toothed bevel gears are described here because they
require special attention as regards the inductor geometry
and in particular the field concentrator elements.
ANALYSIS OF THE CURRENT
HARDENING PROCESS
All geometric changes of a workpiece are referred to as
distortion. Since any distortion results in costly follow-up
processing, the goal is to keep distortion as small as possible.
One of the inevitable distortion types is volume growth
of the section to be hardened during martensitic hardening.
The distortion types that can be avoided are caused by
thermic tensions, internal tensions and machining stresses.
The longer the hardening temperature is maintained, the
higher are these tensions [1, 2]. An existing hardening process
for bevel gears is carburization which can take several
hours (8 - 20 hours) [3].
Quenching can contribute significantly to distortion.
Due to geometric conditions of the bevel gear different
conditions for the flow dynamics of the quenching medium
are available at the tooth tip and at the tooth root.
Severe impact of the Leidenfrost effect must be avoided
for the vaporizing quenching media like polymer solutions
or oils. There must be no distinct vapor layer phase.
If, however, the vapor layer still appears, the boiling phase
is formed parallel to the sinking temperature and further
cooling down induces the convection phase (Fig. 3). Since
these three successive phases have different cooling rates,
they create inhomogeneous stress state in the component.
Even flow dynamics is not given there due to teeth
resp. teeth spaces and it may cause clinging steam bubbles
which lead to lower local cooling rate, thus, inducing
an incomplete martensitic transformation. Complex bath
movements can be used as a solution in order to ensure
sufficiently high rinsing in the quenching medium. During
induction hardening an aqueous polymer solution is usually
used. To keep the Leidenfrost effect as low as possible
in such solutions, corresponding suitable quenches with
appropriate hole pattern are used for the workpiece.
When using the quenching media which do not evaporate
directly from the heated component surface, such as
molten salt or metal, the Leidenfrost effect does not occur.
However, the use of such quenching media is questionable
due to its environmental exposures. Gases are quenching
media with heat transfer coefficients which are virtually unaffected
by the temperature. Their quenching rate is, however,
Fig. 1: Pinion (left) and ring gear
1-2014 heat processing
53

REPORTS
Induction Technology
Fig. 2: Profiles of bevel gears [1] Fig. 3: Leidenfrost-effect [4]
significantly lower. Due to this low quenching intensity their
use is highly limited by the mass of the workpiece. [1]
The distortions of ring gears are mainly noticeable in an
axial run-out and non-circular bore. If the ring gears are not
ground or hard-peeled after the thermal treatment, sufficiently
accurate radial and axial run-out must be ensured
for the subsequent lapping process. This can be realized
only by means of the press quench (fixture hardening).
During fixture hardening the ring gear which has been
heated up to the hardening temperature is transferred to a
hardening unit (Fig. 4). During this process it is placed onto
the base plate (2) over the expanding mandrel (3). Then the
unit is closed by opening the expanding mandrel using
the mandrel (4) with a defined force, after that the planar
rings (5, 6) will hold the ring gear down with a defined
force as well. The quenching medium starts rinsing the
ring gear once the expanding mandrel has been opened.
The open expanding mandrel ensures the alignment of the
ring gear and fixation of the ring gear bore. The planar rings
guarantee that the flange as well as the tooth tip sections
is held in-plane [1].
THE SDF® PROCESS
SDF® is characterized, as the name (Simultaneous Dual
Frequency) suggests, by the fact that two frequencies are
used simultaneously to work with one inductor. There are
three main parameters for configuration of the hardening
process: power value Medium Frequency (MF), power value
High Frequency (HF) and heating time. These parameters
must be adjusted for each workpiece. Besides, the SDF®
process has the following characteristics: short heating
time (between 100 and 500 ms) and high power density.
Due to short heating times the inductor must be adjusted
very accurately to the workpiece. Basically, the MF value
primarily affects the tooth root and the HF value – primarily
the tooth tip. Since these two powers can be set
independently from each other, using the SDF® induction
process and selection of the corresponding parameters it
is possible to generate a hardness profile with an accurate
contour or a close-to-contour hardness profile for a gear.
Since the heating time is short and a smaller volume of
the workpiece is hardened, there is less distortion. Another
advantage of the short heating time is the thin scale layer
which is formed during the heating process. Since it is
very thin, the follow-up processing is reduced or omitted
completely [3].
RING GEAR HARDENED USING THE SDF®
INDUCTION PROCESS
A close-to-contour hardness profile is currently possible
only for gear with modules between 1.8 and 5. It always
depends on the teeth geometry and must be configured
and tested for each component.
Since this analysis only deals with spiral-toothed
gears, the so-called “fingernail” effect can be seen clearly.
Obtaining a close-to-contour hardness is still always
complicated if the workpiece has a helical or spiral gear
because a typical asymmetrical hardness profile can be
observed in every tooth of such gears during induction
hardening. A soft section, also referred to as “fingernail”,
appears on one side of each tooth. This section is present
because the induced currents run along the shortest path
without any influence on this section. This effect depends
on the angle of this gear: the larger the angle, the larger
is the soft section. A typical hardness pattern is shown in
Fig. 5. Numerical simulations have shown that the solution
54 heat processing 1-2014

Induction Technology
REPORTS
of this problem can be reached by guiding the current in
the direction of the teeth. The aim is to develop an inductor
which would make the current flow as described above and
be capable of carrying enough energy (in the range from
10 kW/cm 2 ).
Carrying this amount of energy during the time periods
of approx. up to 300 ms implies that the inductor cooling
must be designed very carefully and the total length of
the inductor must be kept as short as possible in order to
reduce the voltage at the connection point of the inductor.
These designing problems have not been solved completely
until now.
Another approach includes modification of the workpiece
resistance by installing field concentrators on the
upper and lower side of the gear wheel (see Fig. 6). As a
consequence, the magnetic field lines are guided homogenously
into the tooth and, as a result, the heating asymmetry
is reduced [5].
A method which would eliminate the hardening asymmetry
in the helical gears completely is not known yet
and represents an important development objective for
the next years.
To obtain the pattern from Fig. 6, i.e. to reach the reduction
of the “fingernail”, a corresponding receptacle has
been designed. The inductor has been adjusted to the
slant of the gear and the quench is connected to it. The
hole pattern of the quench has also been adjusted to the
workpiece. To ensure the steadiness of the inductor and to
prevent it from being moved by the high electromagnetic
forces during the heating process, this inductor-quench
combination has been reinforced mechanically. The inductor
itself has also been equipped with field concentrators
in order to increase its efficiency.
The heating process is made up of the following steps:
pre-heating, holding time and heating up to the hardening
temperature. For this workpiece the pre-heating time is less
than one second and the SDF® power of approx. 300 kW
is used. Sufficient time is given for the introduced heat to
spread evenly over the area close to the surface. Then the
heating process reaches the austenitizing temperature
within the time of less than 300 ms and SDF® power of
approx. 2,000 kW. In order to avoid cracks during the hardening
process itself, i.e. during quenching, the quenchant,
a high-percentage aqueous polymer solution, should have
increased temperature. Two exemplary hardening contours
are shown in Fig. 7.
PINION HARDENED USING THE SDF®
INDUCTION PROCESS
Since the pinion has a spiral gear like the ring gear, the
“fingernail” effect also plays a role here. Unlike in the ring
gear the gear of the pinion is not positioned planar, it has
a conical shape; therefore, the field concentrators can be
attached as shown in Fig. 6. The workpiece is placed into
a receptacle appropriate for the form. The inductor is a
single- or multi-winding ring inductor with the electric
field adapted specifically to the pinion. The test setup is
shown in Fig. 8. The heating process is made up of the
same three steps like for the ring gear: The heating up to
the austenitizing temperature happens within the same
Fig. 4: Device for the fixture hardening [1]
Fig. 5: Hardness pattern along the teeth length of an
induction-hardened helical gear
1-2014 heat processing
55

REPORTS
Induction Technology
the short heating time allow minimization of distortions.
This results in reduction or elimination of the following
hard machining steps. As a result of this a lot of energy,
time and costs can be saved.
Past experience has proved that the “fingernail” effect
in the examined gear types does not impair their fatigue
strength. Prerequisite for this is that this effect is relatively
small and does not reach into the area of the load.
Furthermore, the process can be integrated in the production
line through a conversion from carburization to inductive
hardening. This simplifies the internal production processes.
Fig. 6: Schematic for reduction of the “fingernail” effect [5]
time period as for the ring gear and requires SDF® power
of approx. 700 kW. Since in this case it is an inner-field
induction process, the thermal efficiency of the inductor
is significantly higher than that of the inductor used in the
ring-gear process [6]. The winding(s) of the inductor are also
reinforced mechanically during this hardening process. A
ring quench located below the inductor is used for quenching.
One exemplary hardness profile is shown in Fig. 9.
CONCLUSION
The SDF® process allows generating close-to-contour hardness
profiles for ring gears and pinions of different sizes.
Setting of the MF and HF powers allows variable form of
the hardening area and, thus, implementation of different
hardening depths. The small size of the heated area and
LITERATURE
[1] Klingelnberg, J.: Kegelräder: Grundlagen, Anwendungen,
Springer Verlag, Berlin, 2008
[2] Benkowsky, G.: Induktionserwärmung, 5. Auflage Verlag
Technik GmbH, Berlin
[3] Krause, C.; Biasutti, F.; Davis, M.: Induction hardening of gears
with superior quality and flexibility using Simultaneous Dual
Frequency (SDF®). American Gear Manufacturers Association,
Fall Technical Meeting 2011
[4] Läpple, V.: Wärmebehandlung des Stahls – Grundlagen, Verfahren
und Werkstoffe, 9. Auflage, Verlag Europa-Lehrmittel
[5] Schwenk, W.; Nacke, B.; Ulferts, A.; Häußler, A.; Biasutti, F.:
Härteeinrichtung, Patent DE102008021306A, (2009)
[6] Schubotz, S.; Stiele, J.: Energieeffizienz von Anlagen zum
induktiven Randschichthärten, Elektrowärme International
Heft 03/2012
Fig. 7: Macroscopic hardening pattern of two ring gears with a module between 4 - 5
56 heat processing 1-2014

Induction Technology
REPORTS
Fig. 8: Trial setting of pinion
Fig. 9: Macroscopic hardening pattern of pinion with module 4 - 5
AUTHORS
Dipl.-Ing. (FH) Marcus Nuding
eldec Schwenk Induction GmbH
Dornstetten, Germany
Tel.: +49 (0) 7443/9649 – 85
marcus.nuding@eldec.de
Dr.-Ing. Christian Krause
eldec Schwenk Induction GmbH
Dornstetten, Germany
Tel.: +49 (0) 7443/9649 – 73
christian.krause@eldec.de
© appeal 097 401
Hardness which pays off
The technology of ALD´s ModulTherm ® heat treatment system for hardening and case hardening of
serial parts has been successfully used for many years, worldwide. The new model ALD ModulTherm ® 2.0
offers optimum process flexibility, reduced manufacturing costs as well as environmental compatibility.
First class service allows for smooth continuous operation.
For more 1-2014 information heat processing please contact us!
ALD Vacuum Technologies GmbH
Wilhelm-Rohn-Strasse 35
63450 Hanau, GERMANY
Phone +49 (0) 6181 307-0
Email info@ald-vt.com
Internet www.ald-vt.com 57

Inductive Melting
and Holding
www.vulkan-verlag.de
fundamentals | Plants and furnaces | Process engineering
the second, revised edition of this standard work for engineers, technicians
and other practitioners working in melting shops and foundries is to
appear in mid-2013. this new version of the title on inductive melting and
temperature maintenance originally published in 2009 is the result of the
great demand generated at that time, and includes coverage of the plantand
process-engineering advances achieved during the intervening four
years. these relate, in particular, to the use of the induction furnace in
electric-steel production, a field in which this environmentally and mainsfriendly
melting system has evolved into a genuine and advantageous
alternative to the electric arc furnace. Characteristic of this is the recent
increase in inverter supply power from its maximum of 18 MW at the
time of publication of the first edition of the book to its present 42 MW
to permit supply of 65 t crucible furnaces.
editor: e. Dötsch
2nd edition 2013, approx. 300 pages, hardcover
Vulkan-Verlag GmbH, Huyssenallee 52-56, 45128 Essen
knowledge for tHe
future
order now by fax: +49 201 / 82002-34 or send in a letter
Deutscher Industrieverlag GmbH | Arnulfstr. 124 | 80636 München
Yes, I place a firm order for the technical book. Please send
— copies of Inductive Melting and Holding 2nd edition 2013
(ISBN: 978-3-8027-2386-5 ) at the price of € 75,- (plus postage and packing)
Company/institution
first name and surname of recipient
Street/P.o. Box, No.
Country, Postcode, town
reply / Antwort
Vulkan Verlag GmbH
Versandbuchhandlung
Postfach 10 39 62
45039 Essen
GERMANY
Phone
e-mail
Line of business
fax
Please note: According to German law this request may be withdrawn within 14 days after order date in writing
to Vulkan-Verlag GmbH, Versandbuchhandlung, Postfach 10 39 62, 45039 essen, Germany.
In order to accomplish your request and for communication purposes your personal data are being recorded and stored.
It is approved that this data may also be used in commercial ways by mail, by phone, by fax, by email, none.
this approval may be withdrawn at any time.
✘
Date, signature
PAIMAH2013

Induction Technology
REPORTS
Induction hardening of
steering racks for electric
power steering systems
by Dirk M. Schibisch, Martin Bröcking
“Power-on-Demand”, maximum mileage, and more functionality – modern automotive steering systems need to offer all
this, while being maintenance-free and low-weight at the same time. Most vehicles already use electric power steering
to assist the steering movement, allowing for easy manoeuvring for parking or at low speeds. The core component of
these complex steering systems is the steering rack, which is heavily loaded during use. Induction hardening increases
steering rack wear resistance and service life. This article describes design features of electromechanical steering systems
and the resulting demands on the steering racks. Various induction hardening methods and hardening machine types
will be presented.
Power or servo steering (Latin: servus = servant) is used
to reduce the human effort required for activating a
vehicle’s steering wheel, primarily at lower speeds or
when stationary. The driver’s steering effort is augmented
by a hydraulic system or an electric motor. Although both
system types have their advantages, electric power steering
has become prevalent in recent times.
Electro-mechanical power steering features a speed-sensitive,
electrical power-assisted steering system that is only
active when needed to assist the driver. It operates entirely
without hydraulic components. Compared to hydraulic power
steering, it offers reduced fuel consumption and new comfort
and safety functions: Active return of the steering to its centre
point improves the steering feel around the mid-point, while
cross-wind compensation comes to the driver’s aid when driving
on a sloping road surface or in a constant crosswind [1].
With electro-mechanical power steering, a microprocessor-controlled
electric servo motor on the steering mechanical
system (steering column or steering gear) assists and boosts
the driver’s steering movements. Hydraulic components, such
as the servo pump and the hoses to and from the servo pump
and steering gear, as well as the hydraulic fluid, are done
away with. In the event of any mechanical damage, e.g., in an
accident, there is no hydraulic fluid to escape, as only grease is
used to lubricate electrically powered steering gears. Instead
of hydraulics, an electric motor provides power to assist the
driver’s steering movement.
A distinction should be made here between the various
designs of electro-mechanical steering systems. The
positioning of the servo unit (motor, control mechanism)
and the design of the reduction gear determine the various
types which are sub-divided as follows [2]:
■■
■■
■■
C-EPS = Column type Electric Power Steering; positioning
of the servo unit in the steering column, gear type
(worm wheel/shaft), e.g., in the BMW Z4.
P-EPS = Pinion type Electric Power Steering; positioning
of the servo unit on the steering gear pinion, as well as
Dual-Pinion drive via a second, separate pinion shaft,
gear type (worm wheel/shaft), e.g., in the Mercedes-
Benz CLA class.
R-EPS = Rack type Electric Power Steering; positioning of
the servo unit in parallel or concentric around the rack,
gear type (belt and ball screw assembly with a parallelaxis
arrangement), e.g., in the VW Tiguan.
Depending on the vehicle type, electro-mechanical steering
systems use over 90 % less power than hydraulic
systems. For passenger cars that comply with the New
European Driving Cycle (NEDC), this equates to fuel savings
of up to 0.4 l/100 km (0.17 gal/100 miles) and up
to 0.8 l/100 km (0.34 gal/100 miles) in city traffic, as the
steering only uses power when the vehicle is actually
being steered. There is no need to maintain constant
hydraulic pressure [3].
1-2014 heat processing
59

REPORTS
Induction Technology
Fig. 1: Typical values for rack force and mechanical performance for
all vehicle classes; based on [3]
Fig. 2: Section of induction-hardened teeth on a steering rack
(source: SMS Elotherm)
With light commercial vehicles the fuel savings are even
greater. Compared to hydraulic power-assist steering, an
electric power steering system in compliance with the
NEDC saves 0.6 l for every 100 km (0.26 gal/100 miles). At
25,000 km per year this produces a saving of 150 l (40 gal)
of fuel thanks to the steering system alone. This amounts
to around € 210 at a price of € 1.40 for a litre of diesel.
Table 1: Advantages of electro-mechanical steering systems in passenger cars [3]
Feature
Safety
Comfort
Steering
Advantage
Stabilizing function
Lane departure warning
Collision-avoidance system
Steering correction system
Park assist
Lane keeping system
Steering feel
Steering performance
Acoustics
Emissions Savings CO 2 10 g/km*
20 g/km**
Consumption Fuel saving 0.4 l/100 km*
* NEDC (New European Driving Cycle)
with a 2 liter Otto engine,
** city traffic only
0.8 l/100 km**
In terms of CO 2 emissions, too, there are considerable
potential savings to be made. Compared to a hydraulic
power steering system, electro-mechanical steering produces
16.1 g/km less CO 2 . At 25,000 km per year this equates
to a saving of around 0.4 t of CO 2 . Furthermore, lawmakers
have approved the introduction of an EU-wide CO 2 penalty
for commercial vehicles that emit more than 147 g/km CO 2 .
With a limit of 175 g/km, it will come into force as early as
2014 and ensure that the limit of 147 g/km is reached in
increments by 2020 [4]. Table 1 shows a summary of the
benefits of electro-mechanical steering systems compared
to their hydraulic counterparts.
Having highlighted the benefits of electro-mechanical
steering systems, a closer look should be taken at the loads
to which the steering racks are subjected. Fig. 1 shows the
various applications of the three major designs of electromechanical
steering systems, namely the C-EPS, P-EPS and
R-EPS. Higher vehicle classes place higher loads on the
rack. While for small to medium-sized cars, rack forces of
3 to 10 kN (675-2,250 lbs.-force) are to be expected, forces
of between 9 and 13 kN (2,020-2,920 lbs.-force) for upper
medium class cars and 13 to 16 kN (2,920-3,600 lbs.-force)
for luxury cars, SUVs or light commercial vehicles should
be anticipated. In cases where the load level is low, the
servo unit is often fixed to the steering column (C-EPS), for
mid-load levels it is secured to a second pinion (P-EPS),
and where demands in terms of the rack force are high, it
is fitted axially parallel to the rack (R-EPS).
As the load level increases, the force transmitted through
the rack rises, resulting in the need for the rack to meet
60 heat processing 1-2014

Induction Technology
REPORTS
correspondingly greater wear resistance and service life
requirements. Two induction-related aspects come into play
here: the use of a base material that has been quenched and
tempered and the induction hardening of the rack based
on the mechanical processing method.
INDUCTION HARDENING METHOD FOR
STEERING RACKS
This paper deals primarily with the second aspect, i.e.,
the induction surface hardening of the mechanically
processed rack. An explanation of the upstream quench
and temper process for heat-treating bars can be found
in the literature [5].
Induction hardening of steering racks
Induction hardening is done to improve material properties.
As a result of the structural transformation that occurs
during hardening, the wear resistance, fatigue strength and
– linked to this – the static strength can be improved [6].
With racks, too, induction hardening is limited here
to the particularly heavily loaded areas of the workpiece
(Fig. 2). These areas comprise the teeth and, depending on
the type of rack, the shaft area, onto which a recirculating
ball screw is incorporated after hardening. The areas to be
hardened are subjected to an alternating electromagnetic
field, which in turn induces an electrical current in the target
area of the rack. The current flow heats the metal to
approximately 900 °C (1,650 F), after which it is quenched
(i.e., rapidly cooled) directly using a special polymer emulsion
and thereby hardened. The penetration depth of the
induced current in the workpiece depends on the alternating
current frequency and the material. For steering racks a
hardening depth of just a few millimeters is usually required,
which can be attained with an operating frequency within
the 3-20 kHz range.
In terms of the induction hardening process, two different
methods have been developed. These are known
as “scan hardening” and “single shot hardening”. With scan
hardening, as shown in Fig. 3 (also called progressive hardening
or progressive radial hardening), the heating and
quenching take place at the same time, whereby a continuous
relative movement between the fixed inductor spray
head unit and the workpiece is required. With racks, the
inductor spray head unit is usually guided along the stationary
clamped rack. With single shot hardening on the other
hand, heating and quenching take place successively in one
or more stations. Single shot hardening is used for greater
penetration depths and/or higher throughputs (Fig. 4).
There are pros and cons to both methods, which need
to be weighed up depending on the hardening task and
throughput requirements, insofar as both methods are even
technically interchangeable in the first place. With single
shot hardening, in general, the higher power requirements
Fig. 3: Scan hardening of a vertically clamped rack
(source: SMS Elotherm)
Fig. 4: Heating using the single shot hardening
method (source: SMS Elotherm)
are offset by much shorter process times, whereas with progressive
hardening lower throughput rates can be achieved
with less power. There are even applications where both
methods can be used at different points of the workpiece.
1-2014 heat processing
61

REPORTS
Induction Technology
required hardness in the finished part. Tempering is done by
reheating the rack to a temperature between 150 and 200 °C
(300 and 390 F). As an alternative to induction tempering,
the rack can also be heated in an electrically heated tempering
furnace. The tempering temperature and duration
influence the hardness reduction, e.g., high temperatures
and short durations may have the same tempering effect
as low temperatures and longer holding times.
HARDENING MACHINE TYPES
The individual machining systems used for rack hardening
are presented and explained in the sections below.
Fig. 5: EloShaft : Integrated manufacturing cell (source: SMS
Elotherm)
Fig. 6: Inductor spray head arrangement in a horizontal twin
station (source: SMS Elotherm)
The induction hardening of steering racks is often performed
in a protective atmosphere. Scale forms at temperatures
within the austenitization range as a result of the
oxygen in the environment. This scale would then have to
be removed again from the racks at great cost and labour.
Flooding the induction chamber with inert gas prevents
scale formation, producing surfaces with virtually no scale
residues.
With steering racks, the hardening process must be followed
by a tempering process, to reduce the hardeninginduced
stresses within the rack. Tempering also reduces
hardness somewhat, which is acceptable because the untempered
surface hardness is usually higher than the final
Scan hardening of racks with vertical workpiece
positioning
Hardening machines with a feed axis are typically used for
producing small batches. Machines with multiple vertical
axes have been developed to increase productivity. The
entire area to be hardened is ‘scanned’ progressively in
the hardening station(s). Circumferential clamping of the
workpieces, for example if the shaft and teeth need to be
hardened, is not necessary.
The workpieces are clamped in position by means of a
clamping device with a workpiece drive and a back stop. A
rotation control device is fitted to the back stop, such that
the rotation of the workpieces can be monitored to ensure
a safe and reliable process. The back stop is designed such
that the steering rack can deflect freely, i.e., without any
significant back pressure during the heating process, in
order to minimize distortion.
Since the tooth area is generally hardened without
rotation, the rack needs to be clamped in the hardening
machine with the correct orientation, or the machine has to
be equipped with a manual alignment aid or, alternatively,
a fully automatic aligning unit. As an alternative to this, the
workpiece may be aligned in an external station and guided
into the hardening machine by means of an automated
system, e.g., a robot. External alignment has the advantage
that it takes place parallel to the process without increasing
the hardening process cycle time.
Rack hardening can be performed using round or formadapted
inductors, which can be designed with one or
several turns. The design of the inductor is finally determined
by the hardening task specifications and the required
throughput. As a rule, multiple-turn inductors can be used
to attain greater feed rates, as the area in which power is
induced in the workpiece is longer than with a single-turn
inductor.
Increasing the wear resistance and fatigue strength in
the tooth area is essentially only required for the teeth.
Hardening only the teeth and tooth base area, however,
causes severe hardening distortion, increasing the time and
labour involved in straightening the rack. In addition, there
62 heat processing 1-2014

Induction Technology
REPORTS
is an increased risk of cracks appearing in the hardening
zone as a result of straightening. The back of the rack in
the area of the teeth is therefore also hardened in order to
reduce distortion. To attain a consistent hardening pattern
in this area, the rack must be able to be positioned in the
inductor. For this it must be traversed horizontally. Therefore
each hardening station is equipped with an additional NC
axis for horizontally adjusting the inductor. In this way, the
hardening depth in the area of the teeth and in the back
of the teeth can be adjusted precisely.
Hardening in the shaft area is done by rotating the
workpieces. Roller burnishing for the ball screw assembly
is applied in this area at a later point in time. For this the
workpiece must be centred in the inductor. For shaft hardening
it is not normally necessary to guide the inductors
over the sensors, as the hardening distortion is minimal.
If the hardening machine is equipped with several hardening
stations, the stations can be operated sequentially.
The workpiece is changed on one station while hardening is
performed on the other. The power supply to the stations is
provided using a common converter (power supply), which
is switched alternately between the stations. If the processing
times are considerably longer than the workpiece
changing times, which is the case when hardening the shaft
and teeth, a second converter can be used. This then allows
simultaneous hardening in parallel in the stations, whereby
the process parameters can be individually adjusted for
each station. Since the stations operate independently,
productivity is correspondingly high.
To ensure the racks can be hardened with minimal scale
formation, as described above, the inductor is installed in
a casing that is closed off as close as possible to the workpiece.
This casing is flooded with nitrogen gas to displace
oxygen. Heating/hardening is therefore performed in an
oxygen-reduced environment to minimize scale formation.
Interlinking of the vertical hardening machines is often
done using a robot, facilitating sophisticated hardening
cells, in which several manufacturing operations can be
carried out (Fig. 5).
Progressive hardening of racks with horizontal
workpiece positioning
The assemblies described above for a vertical hardening
machine can, in principle, also be integrated into a horizontal
hardening machine. A key difference with the horizontal
machine design is that these machines feature an internal
workpiece transport system and can be integrated into a
production line. With this machine concept, too, various
manufacturing steps can be implemented in one cell. For
example, the workpieces can be hardened in one station,
tempered in the next station and straightened in a further
station. Transportation of the workpieces between the individual
units is performed using a walking beam transport
system. Loading and unloading of the walking beam is
performed using a gantry crane.
One difference between the horizontal and the abovedescribed
vertical plant concept is the quenchant guidance
system (Fig. 6). Whereas with the vertical hardening process
the lower part of the rack is cooled throughout the entire
process cycle and the cooling time decreases relatively as
the feed rate increases, the exposure time of the coolant
across the whole hardening zone remains constant with a
horizontal inductor spray head arrangement. As a result,
a more consistent microstructure can be formed. On the
other hand there is a risk that defectively or incorrectly
arranged spray heads could allow quenchant to enter the
inductor, causing inconsistent heating and soft spots.
The hardening process may also be performed in a
nitrogen atmosphere on these machines to minimize scale
formation.
Single-shot hardening of toothed racks with
indexing table transportation
In order to reduce production costs there are machine concepts
available where the shaft area is hardened using the
single-shot hardening method. Roller burnishing is applied
in this area at a later point in time. To reduce handling times
and ensure optimum capacity utilization, an indexing table for
internal workpiece handing is used with this machine concept.
Loading and unloading takes place in one station,
while the shaft is single-shot hardened in the next station.
The tooth section is scan hardened in another station, as
described above. There is also the option of setting up two
additional stations for induction tempering on the indexing
table (Fig. 7).
Fig. 7: Indexing table hardening machine with two hardening
stations; one for single-shot hardening and one for
scan hardening (source: SMS Elotherm)
1-2014 heat processing
63

REPORTS
Induction Technology
Single-shot hardening is well-suited for hardening the
shaft area, as the geometry here is cylindrical and the hardening
distortion is correspondingly minimal. When clamping
the steering rack, any imbalance that may occur when
incorporating the teeth must be offset.
With this modular machine design, internal workpiece
handing and clamping in the hardening stations is performed
separately. For operators this has the advantage that
only one workpiece needs to be examined and evaluated
for quality approval purposes. With conventional indexing
table concepts, one workpiece per clamping unit needs
to be examined and evaluated on the indexing table, as
the position of the workpiece is different in terms of the
range of manufacturing tolerances in each clamping unit.
The corresponding labour and costs associated with the
approval are many times higher.
The single-shot hardening process can also be performed
in a protective atmosphere. For this a split chamber
is built around the inductor. The inductor is horizontally
positioned with the chamber open. Then the chamber is
closed and flooded with nitrogen during the hardening
operation.
CONCLUSION
The current trend of downsizing automotive components
also affects the steering rack. The technical improvements
being made in electric power steering are essentially aimed
at optimizing the efficiency and power density to extend its
use to light commercial vehicles [7]. While the demands in
terms of the service life and wear behaviour are constantly
increasing, the components themselves cannot be any
larger or heavier for weight reasons.
The induction hardening of particularly heavily loaded
points of such racks, as well as the use of correspondingly
high-quality, induction heat-treated starting material, represent
solutions for overcoming this dilemma. The industry
has developed sophisticated manufacturing solutions to
achieve reproducible induction hardening results that meet
relevant demands accordingly.
All the machine concepts presented in this paper use
assemblies that have already been proven and standardized.
These same assemblies can be flexibly reconfigured
to create other custom solutions.
With modular induction machines of a horizontal or
vertical design for the induction hardening of steering racks,
manufacturers are well-equipped for current and future
demands. From hand-loaded machines for smaller quantities
through automated hardening machines in production
lines to complex manufacturing cells, which integrate other
processes as well as the actual induction itself, modern
induction solutions offer perfect, tailor-made solutions for
all requirements every time.
LITERATURE
[1] www.volkswagen.de/de/Volkswagen/InnovationTechnik/
techniklexikon/elektromechanische_servolenkung.html
[2] wikipedia: servolenkung
[3] Presseinformation ZF Lenksysteme iaa 2011 10 Elektrolenkung
d, September 2011
[4] Presseinformation ZF Lenksysteme PT IAA 12 01 d, June 2012
[5] Vorteile der induktiven Vergütung von Rohr- und Stabmaterial,
ewi – elektrowärme international 01/12, Vulkan-Verlag
[6] Pfeifer, H.; Nacke, B.; Beneke, F. (Hrsg.): Praxishandbuch
Thermoprozesstechnik, Vulkan-Verlag GmbH, 2011, p. 386ff
[7] Servolenksysteme für PKW und Nutzfahrzeuge, Verlag Moderne
Industrie 2012, p. 79
AUTHORS
Dipl.-Wirt.-Ing. Dirk M. Schibisch
SMS Elotherm GmbH
Remscheid, Germany
Tel.: +49 (0) 2191 / 891-300
d.schibisch@sms-elotherm.com
Dipl.-Ing. Martin Bröcking
SMS Elotherm GmbH
Remscheid, Germany
Tel.: +49 (0)2191 / 891-412
m.broecking@sms-elotherm.com
64 heat processing 1-2014

Burner & Combustion
REPORTS
Burner control and burner
management systems in industrial
automation systems
by Ulrich Hofmann, Peter Sänger
Today, the communication ability of burner controls and burner management systems is absolutely vital. Due to increasing
networking and the integration of single components into a complete system, it will also be necessary to include
the burner control and/or burner management system in an existing automation system for data acquisition and
visualization of this sub-process. There is an increasing expectation among plant operators for data from all connected
devices and systems in a plant to be accessible from a central location. This paves the way for more efficient operation
and energy-saving measures, as well as making it possible to visualize plant states and detect faults. As a result, it makes
the integration of burner controls and burner management systems a priority. Siemens Simatic ET200S or S7-1200 PLC
systems offer the opportunity to establish a communicative network between these devices and other systems with
ease via Profibus and Profinet. Various burner controls and burner management systems communicate with the Simatic
ET200S or S7-1200 using integration interfaces and relevant software libraries. The following article illustrates the diverse
range of technical options available, demonstrating how flexible it is to integrate Siemens burner controls and burner
management systems into new or existing automation systems.
The connection between LME7x and LME/LMO39x
burner controls and the Simatic PLC systems is based
on a proprietary coupling (BCI), while the coupling used
to integrate LMV2x, LMV3x, and LMV5x burner management
systems is based on a Modbus (Fig. 1). In addition to acquiring
actual, setpoint, and status values for all burner controls and
burner management systems that are capable of communication,
it is even possible to make changes to settings on
LMV2x, LMV3x, and LMV5x systems via the communication
interface in some cases. To ensure maximum safety levels are
maintained, it is only possible to adjust parameters that are
NOT safety-relevant. The safety-relevant parameters for burner
controls and burner management systems are adjusted or
changed locally using either the AZL display and operating
unit or the ACS410/ACS450 PC tool.
The LME7x and LME/LMO39x burner controls are integrated
into Simatic PLC systems by means of a Burner Communication
Interface (BCI), while the LMV2x/LMV3x burner
management systems are connected via a separate Modbus
interface. As both interfaces operate using TTL-compatible signal
levels, the OCI412.10 signal and level converter is required.
This module uses galvanic separation to convert the level
of TTL signals to RS485. The LMV5x burner management
system features a serial communication interface (RS-232)
with Modbus RTU protocol via the AZL5 display and operating
unit. In addition to controlling the Modbus-compatible
LMV2x, LMV3x, and LMV5x burner management systems
directly, it is also possible to control them via SIMATIC PLC
systems using hardware contacts with direct cabling of all
burner controls. Table 1 shows the connections for the communication
modules.
Table 1: Connections for the communication modules
CM1241
CB1241/RS485
CM1241/RS232
Modbus interface
module
Serial interface
module
SIMATIC S7-
S1200
RS-485 Mode
RS-485 Mode
RS-232 Mode
ET200S with
LMV2x/LMV3x/LMV5x
RS-485 Mode (LMV2x/3x)
RS-232 Mode (LMV5x)
ET200S with LME7x/
LME39x/LMO39x
RS-485 Mode
1-2014 heat processing
65

REPORTS
Burner & Combustion
As a Profinet IO controller, the Simatic S7-1200 supports
communication with Profinet IO devices.
Through the TCP/IP standard, the Simatic S7-1200’s
integrated Profinet interface is available with the following
functions:
■■Programming the CPU,
■■Communicating with the Simatic HMI basic panels
for visualization purposes,
■■Communicating with other control units,
■■Communicating with IO devices such as actuators.
Fig. 1: Options for integrating burner controls and burner management systems
into the Simatic S7-1200
Fig. 2: Options for integrating burner controls and burner management systems
into the Simatic ET200S
The available data is read cyclically by the Simatic PLC
systems and buffered in a data module. The data can be
handled further or archived. Setpoint changes are made
directly in the data module for the LMV2x, LMV3x and
LMV5x.
With the Simatic S7-1200, it is possible to activate an
integrated web server to run diagnostics for the PLC and
plant state using a web browser (Internet Explorer, Mozilla
Firefox, etc.). In this context, standard S7-1200 websites can
be used to display current PLC diagnostics information.
User-defined HTML websites are created (with Frontpage,
Notepad++ or Composer, for instance) in order to retrieve
a plant state or further data using the web server.
Of course, data can also be archived from user program
while it is running. The integrated Profinet interface
consists of a fault-resistant RJ45 connection and autocrossover
functionality of the Ethernet connections
supported by a data transfer rate of up to 10/100 MBit/s.
DRIVER MODULES FOR THE SIMATIC
S7-1200/ET200S CONNECTION
The Modbus RTU communication [1] is based on
the master-slave principle, whereby communication
is exclusively controlled by the master. Slaves only
respond to requests made by the master and send
a response package. In this connection, the Siemens
burner management systems are always slaves, while
the Simatic PLC systems are masters. There are two
possible connection types between the burner management
systems’ Modbus interfaces and the Simatic
PLC systems. The systems can either be connected
individually via a point-to-point (P2P) connection, or in
a group via a multi-point connection (MP). This requires
the use of various driver modules along with a different
wiring topology. For a P2P or MP connection, calling
up the appropriate driver module from the respective
Siemens software library (S7-1200 or ET200S library)
establishes the connection to the burner management
systems and cyclically updates the process values. The
following driver modules are available in the library for
connecting the burner management systems:
■■LMV2x/LMV3x:
For connecting an LMV2 or LMV3 that is used to read
the parameters at a quick refreshment rate (< 1 s),
average refreshment rate (< 8 s), and slow refreshment
rate (< 25 s).
■■
LMV5x_fast:
For connecting an LMV5 that is used to read the
most important parameters at a quick refreshment
rate (~ 1 s), average refreshment rate (~ 8 s), and slow
refreshment rate (~ 25 s).
■■
LMV5x_all:
For connecting an LMV5 that is used to read all parameters
at a quick refreshment rate (~ 1 s), average refreshment
rate (~ 8 s), and slow refreshment rate (~ 25 s).
66 heat processing 1-2014

Burner & Combustion
REPORTS
The BCI communication [1], [2] is based on a proprietary
serial communication protocol (pointto-point)
with a fixed rate of transmission and is
also subject to the master-slave principle. Communication
is also controlled here by the Simatic
PLC system as a master, and slaves only respond
to requests. Read access is provided to relevant
process values within the burner controls.
The following driver modules are available:
■■
LME7x, LME/LMO39:
For connecting an LME7x, LME/LMO39x that
is used to read the parameters at a quick
refreshment rate (< 1 s), average refreshment
rate (< 8 s), and slow refreshment rate (< 25 s).
Fig. 3: Burner with operating panel and RWF50 controller (left); detailed view of builtin
KTP600 operating panel (right) [3]
EXTENDED FAULT MANAGEMENT
WITH THE SIMATIC S7-1200
Hermen Enterprises [3] uses a Siemens Simatic S7-1200 for
extended fault management. The LME73’s status and alarm
messages are visualized directly on the burner and, in the
event of a fault, assistance is generated and displayed to
the installer or plant operator. To control the temperature
of the gas-fired heating plants for producing hot water,
the boiler uses the Siemens RWF50.2 boiler controller. The
LME73 burner control provides the entire safety control
for the burner (Fig. 3, left). Here, the boiler controller and
burner control are hard-wired to one another. Communication
between the controller and burner controller is
made via hardware contacts. The RWF50.2 is a compact,
self-adjusting PID 3-position controller with no angular
positioning feedback to the boiler temperature control.
The built-in thermostat function switches the burner on
and off depending on the power consumption. For this,
the RWF50.2 issues the burner release (burner ON/OFF)
via a digital output. Two further digital outputs (3-position
output, OPEN/OFF/CLOSED) are used to issue the required
burner capacity setting to the LME73; this takes place by
means of an air damper controller, for example (Fig. 4).
The gas flow rate is tracked according to the air volume
setting, by a pneumatic ratio control system on the burner.
As alluded to previously, the LME73 burner control is
connected to the Simatic S7-1200 via the OCI412.10 interface
module. Communication between the S7-1200 and LME73
takes place via the proprietary protocol (BCI), and to the
operating panel via Profinet. The connection between the
S7 and the LME73 is established with the appropriate driver
module from the software library provided by Siemens. This
provides the S7-1200 with cyclical access to the LME73’s
data points. Status information and error messages are
displayed graphically on the KTP600 operating panel (see
Fig. 3, right), for example the mains voltage (bottom left),
the flame signal amplifier (above the flame), and the air
damper position in the form of a bar (above the fan). The air
damper position is acquired via a feedback potentiometer
in the LME73. Other pages display status information such
as the program phase, error code, burner startup counter,
and error counter. In the event of an error, the error code is
displayed in plain text with supplementary help texts in the
Fig. 4: LME73 bus connection to Simatic S7-1200
1-2014 heat processing
67

REPORTS
Burner & Combustion
Fig. 5: Configuration and distribution of the firing zones and burning
systems [4]
PLC’s operating panel. This provides the plant operator or
installer with information on potential causes and how to
rectify the error. Additional application information, such
as the temperature, pressure switch, and other measured
values (burner, boiler, or DHW storage tank, etc.) is acquired
via the PLC and used for detecting and rectifying errors.
This is an easy way of providing extended fault management,
whereby plant operators or installers are shown
the solutions to problems. Of course, it is also possible
to forward the information to other areas (control room,
installer) via Profibus/Profinet.
Example error display:
Error code: Loc 2
Error: No Flame at End of Safety Time
Possible causes:
■■
■■
■■
■■
■■
Faulty or soiled fuel valves.
Faulty or soiled flame detector.
Poor adjustment of burner.
No fuel.
Faulty ignition equipment.
CHAMBER KILNS FOR HOUSEHOLD AND
GARDEN CERAMICS
To fire ceramics, chamber kilns are set to a temperature
of between 1,080 and 1,240 °C depending on the product.
This application example describes how a complete
chamber kiln plant was brought up to date by BFT-Industrie
Feuerungstechnik [4]. In the existing plant, the power consumption
of natural gas and electrical energy was too high
and the temperature in the combustion chamber was
not distributed evenly. The uneconomical operation was
essentially due to energy losses in the flue gas exhaust
system and too much excess air in the combustion process.
The objectives of this modernization process were as
follows:
■■
■■
■■
■■
■■
■■
■■
Achieving a homogenous temperature distribution
throughout the entire combustion chamber.
Improving the water absorption tolerances.
Reducing the energy consumption (natural gas and
electrical energy).
Reducing the CO 2 emissions in the flue gas.
Reducing noise emissions from central combustion air
fans in the production building.
Changing the measuring and control plant to Siemens
LME39 and Simatic S7 with Profibus communication
and decentralized signal acquisition.
Generally improving the ceramic’s firing and glazing
quality.
The chamber kiln system (or kiln) consists of two firing
zones that are operated independently of one another with
respect to the way in which they are controlled (Fig. 5).
The associated burners are installed at different heights on
the front and rear side of the kiln. Each of the two highspeed
burners has a capacity of between 20 and 250 kW
and is operated on a modular basis. The cooling process
is performed by the on-site burner. For each burner, the
temperature of the cooling air output is controlled electronically
on a continuous basis via the burner fans.
The entire chamber kiln control was completely
removed and reinstalled along with all of its peripheral
components (combustion air fans, gas/air media distribution
system, I&C control cabinet, electrical cabling).
The burner control and monitoring processes are now
governed by the Siemens burner control LME39. The fan
cabinet is installed next to the burner on the side of the
kiln and comprises the burner controls, the combustion air
supply fan, and the associated pressure monitoring of the
combustion air. This fan cabinet also includes the central
terminal interface for connecting other burner peripherals
and interconnecting the PLC signals.
The gas control loop for each burner was reinstalled
and includes the base load gas piping as well as the bypass
piping with the pulse-controlled gas valve. The pulse gas
valve varies the burner capacity between the base load
and maximum capacity. A gas safety valve is positioned
upstream of the gas piping and controlled via the LME39.
The LME39 starts and monitors the burner. A Siemens PLC
(S7) controls the burner output modulation via the gas
valve control in the bypass piping. To do so, the PLC triggers
a switch-on signal for the burner via a digital output
on the burner controls. Burner control data such as flame
signal strength, burner phase, error code, current operating
voltage, and burner start counter, along with the current
status of the burner controls, is read out by the PLC via
68 heat processing 1-2014

Burner & Combustion
REPORTS
the Burner Communication Interface (BCI). For this, the
OCI412.10 interface module between the PLC and burner
control must be connected (Fig. 6).
To achieve complete combustion over the entire pulse
power range of 0 to 800 pulses/min. during pulse-operated
burner modulation, it is necessary to have the ratio of
combustion air to fuel automatically adjusted in order to
suit the constantly changing pulse frequency. By including
the necessary primary physical parameters such as the gas
inlet pressure at the pulse valve and the kV value of the
pulse valve, a fuel pulse (gas flow rate) that can be defined
in terms of its energy usage is produced in relation to the
valve opening time. When it comes to the temperature in
the kiln, i.e., in the firing zone, the temperature controller
in the S7 control calculates the required pulse frequency
in the range 0 to 800 pulses/min, which corresponds to
an output modulation of between 20 and 250 kW. The
set pulse frequency (gas flow rate) determines the associated
air volume to be set and adjusts the fan between
0 and 100 %. This automated adjustment of the process
air supply ensures complete combustion in every burner
capacity range with minimal excess air.
As a result, savings of 25 to 35 % can be made on fuelrelated
energy and approximately 85 % on electrical energy,
which contributes to a long-term reduction in CO 2 .
The chamber kiln plant is controlled via a Siemens control
station visualization with fully-graphic dynamic representation
(WinCC Version 6.0). The system includes all necessary
controllers, firing curves, and (plant-specific) plant status
displays required for the operating and observation processes.
Here, the visualization PC is integrated into the control
cabinet for the control station. The chamber kiln plant
is controlled by a Simatic S7, which detects all necessary
parameters during the start phase and completes the entire
control problem independently. This means that even if the
PC system fails, the complete ceramic firing process selected
can be completed fully automatically. The system archives
any incidental operating data, such as temperatures or system
states. This data can be retrieved at any time for the
purposes of tracking the firing process by entering the time
and date. The integrated remote maintenance software via
Internet connection allows the entire plant to be operated
from decentralized locations with a fully graphical display
and, in the event of a malfunction, allows countermeasures
to be implemented immediately. The option is also available
to monitor and operate the plant via remote maintenance
software on a smartphone or tablet.
Fig. 6: Diagram of the chamber kiln plant with its components [4]
DRYING GYPSUM WITH A GSI BURNER
AND LMV37
In the German gypsum industry, various burning systems
are used for the calcining process, by which raw gypsum
is heated until dehydrated. Rotary kilns, boilers, and grinding
and incineration facilities are frequently used to produce
plaster of Paris (stucco). Plaster of Paris or multiphase
gypsum can be fired alternately in carrier gas combustion
systems. The grate conveyor kiln (Fig. 7, left) is a tried
and tested system for producing high-fired gypsum. This
involves adding raw gypsum on top of the constantly moving
grate conveyor in various particle size groups (5-60 mm)
of increasing size. During this process, the gypsum layer in
the top area is heated to approximately 700 °C, while the
bottom section reaches a temperature in the region of
300 °C. An ABIC GSI 350 burner with an output range of
between 7 and 350 kW is used to heat and dehydrate the
raw gypsum. The forced draft gas burner features modulating
operation with a control range of 1:50. The Siemens
LMV37.400A2 system with gas/air ratio control is used for
burner management purposes, and is directly installed on
the burner (Fig. 7, right). The burner management system
controls the gas valves and monitors the entire combustion
process. The output modulation takes place electronically
via two SQM33 actuators and corresponds to the defined
ratio control curve that was created during the commissioning
process. The actuators have a positive, frictional
connection with the VKP gas proportional valve/air damper.
During operation, the system operates along the defines
ratio control curve depending on the load. Here, the Simatic
S7-400 assumes full control of the temperature and grate
conveyor kiln. As a component of the overall control unit,
the decentralized Simatic ET200S is connected via Profibus.
On a local level, the LMV37 is connected to the OCI412.10
via the ET200S Modbus interface module. This connection
facilitates data exchange and control via the Simatic S7-400,
and the ET200S link to the burner management system. This
1-2014 heat processing
69

REPORTS
Burner & Combustion
Fig. 7: Diagram of a grate conveyor kiln (left) [5]; GSI burner with installed LMV37.400A2 burner management system
and SQM33 actuator (right) [6]
allows, for example, actual values, status values, and fault
status messages from the burner management system to
be read, the burner capacity to be preset, and the burner to
be switched on or off. Additional hardware cabling between
the PLC and burner management system is not required.
The burner management system data is available in the
control room, where it can be visualized and stored as a
result of the connection with the overriding automation
and control system (Simatic S7-400). Malfunctions and fault
messages are displayed instantly. In the event of a fault,
measures can be taken quickly, downtime is reduced, and
the availability of the grate conveyor kiln is increased.
INDUSTRIAL BURNERS WITH LMV52 FOR
THERMAL OXIDATION
Industrial burners are at the heart of every thermal process-based
production line, and the quality of the final
product depends primarily on the burner’s reliability and
performance. Low maintenance effort and maximum
availability, high levels of energy efficiency and seamless
integration into existing automation systems are the key
requirements placed on these industrial burner systems.
Among its other applications, Crone’s Tricom burner [7] is
used in the automotive industry as part of modern bodywork
drying systems for treating exhaust air in paintshops.
This is due to its versatile method of operation on the one
hand, and the Tricom burner’s extended control range on
the other. Crone updated five thermal oxidation plants
in the paintshop of a car manufacturer and went on to
complete further improvement measures. Fig. 8 illustrates
the thermal oxidation plant with the Tricom burner along
with the associated control cabinets and corresponding
control technology.
Controlling the combustion process in this thermal oxidation
plant requires a very high level of repeatability for
the controlling elements in order to set the affected gas
flow rates in the respective phases. For the Tricom burners,
the LMV52 burner management system is used in conjunction
with the QRI flame detector and SQM45 actuator.
Not only do the gas control loop components have to be
selected carefully (on the basis of gas dampers), but a sufficiently
accurate level of control is required in relation to
the actuators. For this purpose, the preset operating points
must be approached in the form of ramps so that stable
flame images can even be generated where conditions are
variable (e.g., in a combustion chamber). The appropriate
ramp points are adjusted by the AZL display and operating
unit during the on-site installation process.
The LMV52 can either be installed directly in or on the
burner, or even in a control cabinet by means of a powerful
data bus (cable length of up to 100 m). The LMV5 burner
management system offers variable program sequences for
controlling the burner control and is fitted with an electronic
safety limit thermostat. Load control is in the form of a PID
temperature/pressure controller featuring an algorithm for
low-wear cold start of thermal processing plants. Together
with the universal infrared flame detector, UV flame detector,
or ionization electrode, the LMV5 ensures continuous
trouble-free operation. A very high level of repeatability and
a broad control range are ensured through the addition
70 heat processing 1-2014

Burner & Combustion
REPORTS
of other system components such as the SQM45/SQM48
actuator with a control accuracy of 0.1° (900 increments
above 90°) The robustness of the electronic ratio control
system is on a par with that of more traditional solutions,
while its ability to set independent gas/air ratio curves and
ignition positions is, in fact, superior.
A key consideration is the connection between the
LMV5 burner management system and an existing PLC process
automation system. After replacing the old plant, the
LMV5 system takes over the direct control of the existing
PLC process automation. The diverse range of configuration
options (3-point, 4-20 mA, 0-10 V, or digitally via bus) means
that the LMV5’s load control can even be adapted to suit
existing plants with ease. The easiest way of connecting
to an existing Simatic S7 is via an ET200S with a Modbus
interface module and the verified software library modules
(see Fig. 2). Even in the event of a process control or communication
failure, it is still possible to automatically revert
back to the internal load control if required.
As a result of taking structural measures and using the
LMV52 burner management system, the gas consumption
in the paintshop’s thermal oxidation plants has reduced by
approximately 25 %, while the NO X emissions are down
to 30 mg/m 3 , the CO emissions to 10 mg/m 3 , and C ges to
below 2 mg/m 3 . This significant reduction in the amount
of fuel consumed means that the costs involved in the
updating process are covered in no time at all.
CONCLUSION
The diverse range of applications discussed in this article
demonstrate the ease with which Siemens burner
controls and burner management systems can be integrated
into an existing automation and control system.
The communicative connection enables the plant operator
to access various parameters of the burner control or
burner management systems and thereby visualize key
status information such as setpoint/actual values and
fault status signals. In the case of the Modbus-compatible
burner management systems, there is also the option of
controlling the burner via the bus connection and making
changes to parameters that are NOT safety-relevant.
As the various example applications illustrate the communicative
connection between the burner control or
burner management system and an overriding automation
and control system not only simplifies operations
management, but also offers increased monitoring and
fault diagnostics capabilities.
LITERATURE
[1] Communication software for connecting LMV2, LMV3, and
LMV5 burner management systems via Modbus. CC1J7556en,
Siemens Building Technologies, 2013
Fig. 8: Thermal oxidation, Tricom burner, and a thermal oxidation
control cabinet [7]
[2] Connecting LME burner controls with SIMATC S7. Industry
Automation and Drive Technologies Service & Support Portal;
Article ID no. 56651824: http://support.automation.siemens.
com/WW/view/en/56651824
[3] Hermen Enterprises Ltd., Hong Kong
[4] BFT-Industrie Feuerungstechnik, Ehingen, Germany
[5] Gips-Datenbuch (Gypsum data book), Bundesverband der
Gipsindustrie e.V. (Federal German Association of the Gypsum
Industry), Darmstadt, Germany, 2006
[6] ABIC Brennertechnik GmbH, Salem, Germany
[7] CRONE Wärmetechnik GmbH, Rhauderfehn, Germany
AUTHORS
Ulrich Hofmann
Siemens AG
Rastatt, Germany
Tel.: +49 (0) 7222 / 598-441
ulrich.hofmann@siemens.com
Peter Sänger
Siemens AG
Frankfurt am Main, Germany
Tel.: +49 (0) 69 / 797-2111
peter.saenger@siemens.com
1-2014 heat processing
71

fabtechcanada.com
MARCH 18-20, 2014 | TORONTO CONgReSS CeNTRe
ONLY
CANADA’S
exclusive fabricating, welding, metal forming and finishing event
Where You Need To Be!
If your company provides services for manufacturing
then FABTeCH Canada is for you!
3 Days Only
> Discover new products in the marketplace
> See live machinery demonstrations
> Network with industry peers
Register Today at
fabtechcanada.com
CO-SpONSORS
STRATegIC pARTNeRS
FABTECHCANADA_8857_7X10_Ad .indd 1
12/5/13 2:51 PM

Burner & Combustion
REPORTS
Application of regenerative
burners in forging furnaces
by Ales Molinek, Günther Reusch, Josef Srajer, Josef Domagala
A demand for lower energy consumption and low emissions resulted in the application of regenerative burner technology
also in forging furnaces. Regenerative burners installed in side walls and burning above the charge have already
been often used, especially in large furnaces. Meanwhile, regenerative burners with flat flame are increasingly used in
forging furnaces. They are installed similar as conventional burners in the side walls and enable substantial energy savings
compared with systems involving a central recuperator. This article describes the application of regenerative flat
flame radiation burners in a forging furnace.
Nowadays, the application of flat flame burners in
forging furnaces is state of the technology. In these
burners, the combustion air is fed to the combustion
process with a strong spin. The burner blocks have a
special shape opening outwards. These features result in a
flat flame spreading along the wall surface. Simultaneously,
the furnace gases are sucked up along the burner axis
into the burner centre and intermix with the combustion
gases. This generates a strong recirculation of the furnace
atmosphere, which multiply exceeds the amount of fed
air and it is comparable with the recirculation achieved be
means of high velocity burners.
The flat flame burners (Fig. 1) are installed in the furnace
side walls, staggered in one or two rows lying upon
another (Fig. 2). The main advantage of the application of
flat flame burners is a reduction in the risk of the material
surface overheatingt. The support beams for the charge
can be smaller and positioned in any order compared to
applications with high velocity burners. The hazard of the
furnace hearth by the scale and the casting powder is
lower. Another type of burner with flat flame involves flat
flame radiation burners. While flat flame burners form the
flame primarily on the wall surface, the combustion in flat
flame radiation burners mainly takes place in the area of the
burner block (Fig. 3). An extreme swirl of combustion air
and a special cup-shaped form of the burner block result in
the combustion of the fuel within the burner block, which
is heated up to a high temperature. The heat transfer by
solid body radiation is more intensive than in typical flat
flame burners (Fig. 1), this resulting in a much more efficient
use of the fuel energy. The combination of strong radiation
(at 500 - 600 mm from the wall surface the radiation
field is constant enough) and very intensive recirculation
of the furnace gases guarantees a faster and more uniform
heating of the charge.
REGENERATIVE FLAT FLAME RADIATION
BURNERS
Over the past few years, regenerative flat flame burners
have become increasingly widespread in forging furnaces.
A regenerative burner consists of a burner and regenerator
filled with ceramic material. As burners flat flame or flat
flame radiation burners are used. However, these burners
have special nozzle systems to keep the NO x emission low
at higher air preheating. The burners have a refractory
inner insulation.
The gas nozzle is made from special heat-resisting steel.
It is refractory insulated and air-cooled. In some burners,
non-cooled special gas nozzles of silicum carbide are used.
Fig. 1: Flat flame burner (Source: Elster-Kromschroeder)
1-2014 heat processing
73

REPORTS
Burner & Combustion
Fig. 2: Flat flame radiation burners in a forging furnace
(Source: Vitkovice Schreier)
Fig. 3: Flat flame radiation burner (Source: Bloom Engineering)
Fig. 4: Regenerative flat flame radiation burner
(Source: Bloom Engineering)
The design of a regenerative flat flame radiation burner is
shown in Fig. 4. Ceramic balls (diameter approx. 20 mm)
or honeycomb-shaped ceramic modules are used as a
regenerator medium. Although the honeycomb modules
require fans with less air pressure and lower suction at the
exhaust gas side, they are nevertheless less robust for the
difficult operating conditions in forging furnaces.
Because of the high bulk density of the ceramic balls
compared to the honeycomb modules, the regenerators
with balls can be constructed smaller at the same switchover
times. The ceramic balls store more heat than the
honeycomb modules (only an approx. 2 mm thick layer of
the ceramic material takes part in the active heat exchange).
This property makes it easier to maintain the thermal equilibrium
between the individual regenerators during ON/
OFF operation of the burners. The handling of the ceramic
bed consisting of balls is much easier during cleaning than
that with honeycomb modules. The flat flame radiation
burners with regenerators using ceramic balls are considered
in this article. The regenerative burners are normally
installed in pairs, whereby the connection between two
burners is realized using pipes or logically via the electronic
controls. Each burner is equipped with a gas solenoid
valve, an air switch valve and a switch exhaust gas valve
(Fig. 5). While one burner burns, the exhaust gases are
sucked through the other burner and its regenerator.
Hot exhaust gas transfers the heat to the ceramic bed,
which stores the heat until switching over the system. The
switch-over occurs after a definite time. The cold combustion
air flows through the hot regenerator, heats up and
flows into the burners now operating, while the exhaust
gas flows through the regenerator of the deactivated
burner.
The hot air temperature in the regenerative burner
system is only 150 °C lower on average than the temperature
of the furnace gases led to the regenerator. This temperature
difference of 150 °C remains almost unchanged
through the turn down range of the burner, contrary to
burners with honeycomb regenerators.
The high level of air preheating makes the system
extremely efficient. In order to maintain the balance
between the heat transferred to the exhaust gas and the
heat given off from the air, approx. 10 % of the furnace
gases are not led through the regenerator, but instead
directly “hot” out of the furnace. The furnace pressure control
is realized by regulating this hot exhaust gas volume.
The exhaust gas volume routed to the flue, comprising
“hot exhaust gas” (temperature up to 1,300 °C) and “cold
exhaust gas” (approx. 200 °C), has a mixing temperature of
approx. 300 °C. A switch-over cycle lasts 40 to 90 seconds,
the switch-over itself 2 to 3 seconds. The burners can be
controlled continuously as well as in ON/OFF or HIGH/
LOW/OFF mode.
74 heat processing 1-2014

Burner & Combustion
REPORTS
Fig. 5: Principle of the regenerative burner system
Fig. 6: Energy savings potential of a regenerative burner system in
comparison to a central recuperator system (air temperature
450 °C)
The energy saving potential resulting from the high air
preheating, compared with a central recuperator system (air
temperature 450 °C), is shown in Fig. 6. The diagram reveals
that the energy saving potential significantly depends on
the furnace temperature. The saving at a furnace temperature
of 1,000 °C is only approx. 17 %, this rising to 30 % at
a furnace temperature of 1,250 °C.
The calculation of the total energy saving potential with
the regenerative burners in a forging furnace must consider
the progression of the furnace temperature and the changing
fuel flow used during the individual time intervals of
the heating cycle.
REGENERATIVE FLAT FLAME RADIATION
BURNERS IN A FORGING FURNACE
Regenerative flat flame radiation burners were installed
in a forging furnace at Vitkovice Heavy Machinery (CZ),
this commencing operation at the beginning of 2013. The
forging furnace car bottom (Fig. 7) serves for heating and
intermediate heating of blocks to a forging temperature
of 1,250 °C for the press 120 MN. The furnace data is summarized
in Table 1.
The flat flame radiation burners used utilize the principle
of air staging in order to suppress NO x emission. Part of
the combustion air is strongly swirled as primary air in the
ceramic air nozzle and then routed into the burner block
close to the gas flow. The remaining air is fed to the combustion
process as secondary air through the tangentially
arranged openings in the burner block. The cooling air for
the gas nozzle is not routed into the furnace but instead
into the open air. This allows to maintain a low O 2 content
in the furnace atmosphere, also during the holding times.
The special construction of the connection between
the burner and regenerator enables a fast disconnection
of the regenerator for maintenance purposes. The burners
are provided with ionization supervised pilots. The main
flame is monitored using a UV cell. The burners installed
in the furnace wall are shown in Fig. 8.
Six flat flame radiation burner pairs with an output of
730 kW each are installed in the furnace. The burners are
staggered installed in both furnace side walls. The number
of burner heads was chosen as for conventional hot air
burners. When planning a regenerative system, it is by no
means necessary to provide twice the number of regenerative
burner heads, compared with conventional burners.
Although the burners burn ON/OFF in pairs, they are to
be considered, taking in account short switching cycle
times, as continuously operated burners in terms of heating
technology. The number of burner heads in a charge
furnace with regenerative burners is therefore similar to a
conventional heating system. Nevertheless, the output of
the individual regenerative burner heads is higher than in
a hot air system.
The furnace is equipped with controls based on a Rockwell
automation PLC with visualization. Three temperature
control zones are established. The burners are controlled
in HIGH/LOW/OFF mode, whereby the low load is approx.
40 % of the burner nominal capacity. Special software is
installed for management of the regeneration cycle times,
this enabling an optimum, uniform temperature control
in the temperature holding phases of the heating cycle.
The gas/air ratio is controlled individually for each burner.
The exhaust gases from the furnace (approx. 90 %) are
extracted through the burners and regenerators using a
1-2014 heat processing
75

REPORTS
Burner & Combustion
Table 1: Furnace data
Furnace type
Fuel:
Low heating value MJ/Nm 3 34
Type of combustion
Burner ignition
Main flame burner
Number of burner pairs 6
Forging furnace
Natural gas
Regenerative
flat flame radiation burner
Ignition burner
UV cell
Capacity per burner pair kW 730
Furnace input kW 4,380
Furnace inside width mm 4,500
Furnace inside height mm 3,900
Furnace inside length mm 10,200
Height of support beams mm approx. 800 mm
Charge weight including support beams t 300
Furnace temperature °C 1,250
Max. furnace temperature °C 1,300
Minimum controlled furnace temperature °C 600
Uniformity of charge temperature after holding time K +/-10
suction fan. The remaining exhaust gases are
led “hot” out of the furnace through the opening
in the back furnace wall in the draught
diverter. The sucked exhaust gas flow is controlled
proportionally to the total air volume
by means of the control of the fan suction.
Fig. 9 shows the view of the burners from
inside the furnace and the back furnace wall
with the fans.
Some operating parameters were evaluated
from the relatively short operating time of the
furnace (commissioning in March 2013). These
are shown Table 2.
Initial short-term experience with the
installed regenerative flat flame radiation
burners has revealed that the average specific
heat consumption of the furnace is at least
16 % lower than in a comparable forging furnace
with a central recuperator system and
an air temperature at the burner of 450 °C. In
the case of a higher specific hearth load, the
expected savings are up to 25 %. The measured
emission values are low and better than
expected.
Table 2: Operating parameters
March 13 April 13
Natural gas, low heating value MJ/Nm 3 34.00 34.00
Natural gas, low heating value kWh/Nm 3 9.44 9.44
Production t 554 1,633
Operating time h 256 671
Gas consumption m 3 24,770 74,510
Mean output t/h 2.16 2.43
Mean gas consumption m 3 /t 44.71 45.63
Mean energy consumption MJ/t 1,520 1,551
Mean energy consumption kWh/t 422 431
Fig. 7: Regenerative flat flame radiation burners in the forging furnace
(Source: Vitkovice Schreier)
Fig. 8: Flat flame radiation burners installed
in the furnace side wall
(Source: Vitkovice Schreier)
76 heat processing 1-2014

Burner & Combustion
REPORTS
a) b)
Fig. 9: Flat flame radiation burners in forging furnace (Source: Vitkovice Schreier)
a) View of the burners from inside the furnace, b) View of the back furnace wall
CONCLUSION
The application of flat flame radiation burners in combustion
systems for forging furnaces is nowadays state of the art. A
further development of this burner technology involves
regenerative burners. Regenerative flat flame radiation burners
enable energy savings up to 25 % in comparison to a
system with central recuperator, thanks to a high level of air
preheating. The relatively low oxygen content in the furnace
atmosphere allows a low-scale heating of the material.
The positive experience with the described installation
in a forging furnace demonstrates this technology
to be a proven means of reducing energy consumption
and hence production costs. The low specific emissions in
conjunction with a significantly lower exhaust gas volume
allow a substantial reduction in the absolute emission in
t/a. The efficient measuring and control systems enable a
large control range for the burner system and a uniform
heating of the charge in conjunction with HIGH/LOW/OFF
operation of the burners and a special software.
[4] Sheikhi, S.: Latest developments in the field of open-die forging
in Germany. Stahl und Eisen, 4/2009
AUTHORS
Ales Molinek
Vitkovice Schreier s.r.o.
Ostrava, Czech Republic
Tel.: +420 (0) 595 / 956 574
schreier@ova.comp.cz
Günther Reusch
Bloom Engineering (Europa) GmbH
Düsseldorf, Germany
Tel.: +49 (0) 211 / 500 91 -31
g.reusch@bloomeng.de
LITERATURE
[1] Teufert, J.; Srajer, J.; Domagala, J.: Anwendung von Flachflammenstrahlungsbrenner
in Schmiede- und Wärmebehandlungsöfen,
Gaswärme International No. 5/2009
Josef Srajer
Vitkovice Schreier s.r.o.
Ostrava, Czech Republic
Tel.: +420 (0) 595 / 956 574
schreier@ova.comp.cz
[2] Molinek, A; Mohyla, D.: Project documentation, Vitkovice
Schreier s.r.o.
[3] Pfeifer, H.; Nacke, B.; Beneke, F.: Handbuch der Thermoprozesstechnik,Teil
II. Vulkan-Verlag, 2011
Josef Domagala
Engtra Engineering & Trade Services
Erkrath, Germany
Tel.: +49 (0) 173 / 373 0576
j.domagala@engtra.de
1-2014 heat processing
77

1 - 3 April 2014
Centro de Exposições Imigrantes
São Paulo/SP, Brazil
ALUMINIUM BRAZIL
2014
www.aluminium-brazil.com

Research & Development
REPORTS
A new approach for coupled simulation
of liquid metal flow, free
surface dynamics and electromagnetic
field in induction furnaces
by Sergejs Spitans, Egbert Baake, Andris Jakovics
Induction furnaces that ensure contact less control of electromagnetic (EM) stirring, molten metal free surface and temperature
are widely applied in metallurgical industry. Requirements for the free surface shape and behavior are defined
by the different tasks of particular technological processes.
Induction furnaces that ensure contact less control of electromagnetic
(EM) stirring, molten metal free surface and temperature
are widely applied in metallurgical industry. Requirements
for the free surface shape and behavior are defined by
the different tasks of particular technological processes.
For example, overheating temperatures for metal evaporation
and coating applications can be obtained in case of EM
levitation since there is no contact between the free surface
that should be stabilized and the crucible [1].
Meanwhile, the dynamics of free surface might be complicated
by the interaction between the free surface shape, EM
field and flow, as well as notably unsteady due to the switch
between the furnace power regimes, mean flow instability
and turbulence.
Since the control of free surface is significant for EM processing
of metallic materials, the numerical models that consider
free surface dynamics are in high demand.
Advanced multiphysical processes like energy and mass
transfer, crystallization and homogenization of alloying particles
are calculated nowadays in 3D with fixed hydrostatic steady
free surface shape and précised Large Eddy Simulation (LES)
turbulence description [2].
Free surface dynamics of EM levitated melt, flow and energy
transfer in 2D consideration, as well as crystallization processes
with free surface behavior in EM induction furnaces were successfully
simulated using simplified two-parameter turbulence models
[3]. The first results of 3D numerical calculation of liquid droplet
dynamics in a high DC magnetic field were published recently [4].
However, at the present moment there is no approach
developed for 3D calculation of multiphysical processes in EM
induction equipment with consideration of free surface dynamics
and application of LES description for turbulent flow. The
previous investigations revealed that in case of Induction Crucible
Furnace (ICF) with two characteristic mean flow vortexes
only the LES model gives comparable results to experimental
measurements [2].
In this article a new general approach for coupled 3D simulation
of liquid metal flow, free surface dynamics and EM field
in induction furnaces of various designs is presented [5]. Furthermore,
the implemented model is adjusted for the case of
EM levitation and can be used with précised LES turbulence
description [6].
ASSUMPTIONS OF THE NUMERICAL MODEL
Due to harmonic nature of EM field and induced eddy
currents, the Lorentz force
f Lor can be decomposed into a steady and harmonic part
that oscillates with double frequency
f = f + f
⋅ cos 2ωt+
ϕ
Lor Lor Lor
( )
where ω is an angular frequency of harmonic EM field and
φ is a phase.
Because of much greater inertia times of melt in comparison
to the alternate EM field timescale (ω/(2π) > 50 Hz), only
the steady part of the Lorentz force is taken into account.
Let us consider the non-dimensional frequency ŵ that shows
(1)
1-2014 heat processing
79

REPORTS
Research & Development
the relation between the induced and external EM field, and
magnetic Reynolds number Re m that gives the relation between
EM field that is generated by the flow and external EM field
2
00 m 00 0
ˆω = ωσμ r and Re = σμ r v
where σ is electric conductivity, μ 0 – permeability of vacuum,
r 0 and v 0 – characteristic length and velocity.
Combining ŵ and Re m it can be shown that in typical case
of induction furnace
EM field generated on account of the flow is insignificant
in comparison to induced EM field.
Assuming no free charge in the system and neglecting
displacement currents (no EM wave radiation) the
reduced Maxwell equation system in addition with
reduced Ohms law (no EM field generation by the flow) is
used for harmonic analysis with finite element method in
ANSYS Classic and the Lorentz force distribution in melt
at particular free surface shape is obtained.
In the hydrodynamic (HD) part of calculation the Navier-Stokes
equation for incompressible fluid is solved with
finite volume method in ANSYS Fluent. In typical cases
of ICF the Reynolds number
Table 1: Externally coupled EM and HD problems for numerical
calculation of free surface dynamics of molten metal
(2)
(3)
Re = r v ρ/ η>
10 3 (4)
0 0
indicates on fully developed turbulent flow (ρ and η stand
for density and dynamic viscosity of fluid), thus k-ω SST
or LES turbulence model is used additionally.
Volume of Fluid (VOF) numerical technique is applied
for calculation of two-phase flow dynamics. In VOF
technique the phase distribution is represented with
a scalar volume fraction field F(x i , y i , z i , t). In particular
case, F = 1 when mesh element contains primary phase
(melt) and F = 0 when element contains secondary phase
(air). Accordingly, when phase surface crosses element
- 0 < F < 1. For phase dynamics the transport equation
is solved
∂F/
∂ t+ v⋅∇ F=
0 (5)
and free surface is reconstructed as isosurface of F = 0.5.
Volume density of surface tension force is calculated as
fγ = −γ ∇⋅nnδ γ
( ) (6)
where γ is surface tension coefficient, is free surface
normal and δ γ is Delta function that ensures that surface
tension force is located only at free surface.
TECHNICAL IMPLEMENTATION OF
NUMERICAL MODEL
Calculation of free surface dynamics of EM induced metal
flow is arranged by means of ANSYS Classic for EM calculation,
ANSYS Fluent for two-phase flow calculation, ANSYS
CFX for post-processing and their external coupler – a
batch file (Table 1).
Initial free surface shape of molten metal, as well as
every instant shape obtained with HD calculation, is written
into a file. This file contains free surface keypoint (KP) numbers,
KP coordinates and series of KP number sequences
that indicate the order of free surface KP connection for
definition of elementary polygons.
Transferring free surface KPs and elementary polygons
from CFX-Post to ANSYS Classic a self written filtering procedure
is performed in order to avoid generation of degenerate
surface polygons that have great edge length ratios and
cause problems in ANSYS Classic volume mesher. Hence,
filtered free surface consisting of elementary triangular
non-degenerate areas is obtained and the finite element
mesh for EM problem is constructed.
Then the distribution of harmonic EM field is calculated for
the fixed free surface shape. The coordinates of alloy mesh
element centroids, as well as the values of Lorentz force density
components, are retrieved and written into a file. In the
beginning of the transient HD calculation the Lorentz force
density is interpolated on the Fluent finite volume mesh and
80 heat processing 1-2014

Research & Development
REPORTS
Fig. 1: Geometry of IFCC with sectioned crucible [7] (a) and mesh for EM calculation (b). As well as measured [7] ( )
and calculated ( ) steady free surface shapes, Lorentz force distributions (on the left) and steady flow patterns
(on the right) for different initial fillings h ( ) and power regimes
(c) h = 46 %, I ef = 3154 A; (d) h = 87 %, I ef = 3789 A;
(e) h = 65 %, I ef = 1929 A; (f) h = 65 %, I ef = 2956 A; (g) h = 65 %, I ef = 3566 A
used as mechanical momentum source in two-phase flow
equations. Then the calculation of unsteady flow is performed
for sufficiently small time interval for which the slight change
of free surface shape can be considered insignificant for the
Lorentz force distribution.
Unphysical air acceleration due to inevitably diffused interface
in VOF formulation is damped by regular air velocity reinitialization
in a small distance from the free surface of the melt.
Such technical trick allowed to ensure a stable calculation of
free surface dynamics for the case of highly pronounced EM
skin-effect. By the end of HD calculation a new transient free
surface state is obtained and written into a file. The recalculation
of the Lorentz force distribution upon the new free surface
shape is performed further and the repeat of the whole
calculation loop ensures fully automatic free surface dynamics
computation in 2D or 3D consideration.
MODEL CAPABILITIES
Molten metal meniscus shape in Induction
Furnace with Cold Crucible
In Induction Furnace with Cold Crucible (IFCC), which is
widely used for melting reactive metals for high purity
castings, the melt is confined by EM field and abutted only
upon the skull at the bottom of water-cooled crucible.
Experimental measurements of aluminum melt free surface
shape in industrial IFCC [7] were used for validation of
the model. The furnace consisted of copper crucible wall
divided on 26 sections with a short circuit ring in the lower
part, unsectioned copper bottom and copper inductor with
five turns (Fig. 1, a).
On account of the symmetry of setup the EM calculation
was performed only for one section considering azimuthal
inhomogeneity of EM field due to the sectioned crucible
(Fig. 1, b). Air gap of 1 mm was ensured between the melt,
the bottom and the crucible walls due to the great electrical
resistivity of the skull that appears in the contact regions
between the melt and water-cooled crucible.
Meanwhile, the HD calculation was performed on
a mesh with one element resolution of section in azimuthal
direction that ensured azimuthal averaging of
the Lorentz force for the 2D axisymmetric approximation.
The comparison between the measured [7] and calculated
1-2014 heat processing
81

REPORTS
Research & Development
free surface shapes of molten aluminum in IFCC at different
initial fillings and power regimes revealed a fine correlation
between the model prediction and experiment (Fig. 1, c-g)
and approved accuracy of developed numerical approach.
Free surface dynamics of melt in Induction Crucible
Furnace
The oscillation period of molten metal free surface in
axisymmetric ICF is estimated analytically [8]. In this small
amplitude approximation the Lorentz force is considered
radial and constant and the typical oscillation period T is
fully dependent on the crucible geometry (1)
( ) ⋅ ( ⋅ )
−
theor
2 12 / 12 /
0 1
1 0 0
T = πr λ ⋅g tan λ h / r
(7)
where r 0 is crucible radius, h 0 is initial filling and λ 1 = 3.83 –
first zero of the Bessel function J 1 .
In order to verify the free surface dynamics predicted by our
model an industrial type ICF adopted from [8] with crucible
that is already filled with molten aluminum is considered
and it is assumed that at initial time moment of t = 0 s the
furnace instantly reaches its operating state.
2D transient calculation results for Lorentz force density
distribution, developing flow pattern and free surface
shapes at particular time moments are shown in Fig. 2
(video_1 - QR Code).
The dynamics of free surface profile (Fig. 3) sketches
free surface regular oscillations and proves that the discrepancy
between the numerically obtained oscillation
period T calc = 0.68 s and analytical approximation (7) T theor
= 0.676 s is less than 1%. Moreover, the calculated instant
free surface states are in good qualitative agreement with
calculation from [8] (Fig. 3).
Parameter studies for conventional EM levitation
For EM processing of metallic materials at great temperatures
and high purity a contactless method of EM levitation
melting is known to be appropriate since older times.
For instance, the behavior and conditions of EM levitated
molten aluminum sample (m = 21.5 g) have been investigated
experimentally [9]. The laboratory-scale EM levitation
furnace consisted of two coils that were fed with counter
oriented alternate currents (Fig. 4, a).
A numerical simulation of particular experiment in 2D
axisymmetric consideration has already been performed
by V. Bojarevics et. al. using a self written software [3]. The
results appeared to be in a good agreement with experimentally
observed “spinning top” shape and indicated on a
fully turbulent two torroidal vortex flow structure (Fig. 4, b).
Particular levitation experiment was numerically reproduced
by our model in 2D axisymmetric (Fig. 4, c) and full
3D (Fig. 4, a) consideration (video_2 - QR Code).
The comparison of literature data for the flow pattern,
Lorentz force and droplet shape revealed a good correlation
with our simulations.
Using the developed 2D numerical model of E. C. Okress
et. al. levitation experimental setup [9] (Fig. 4, a) a series of
Youtube Videolink
Video 1 Spitans, Baake, Jakovics
Youtube Videolink
Video 2 Spitans, Baake, Jakovics
Fig. 2: 2D calculation results for Lorentz force density (on the left), flow pattern (on the right) and free surface dynamics at different time
moments in big industrial ICF
82 heat processing 1-2014

Research & Development
REPORTS
steady state free surface calculations were performed in order
to illustrate the effect of parameter change on the levitated
drop (Fig. 5). Experimental values of surface tension γ = 0.94
N/m, melt density ρ = 2,300 kg/m 3 , AC frequency f = 9.8 kHz
and inductor effective current Ief = 0.6 kA were used as a
reference case.
The parameter studies performed clearly illustrate that for
the case of conventional EM levitation in axisymmetric vertical
EM field, the Lorentz force singularity is obtained on the symmetry
axis. The melt outflow and leakage can be hindered
in this lowest point on the axis of a levitated sample only by
the melt surface tension and therefore, the charge weight is
limited. Pursuing the interest of scaling-up the levitated charge
it is reasonable to consider EM levitation in a horizontal field.
EM levitation in a horizontal single-frequency field
The next step of developed model verification is based on
O. Pesteanu experimental measurements and his 2D steady
simulation results of aluminum melt levitation in a single
frequency EM levitation melting device [10]. This EM levitation
furnace consists of ferrite yoke and copper inductor
with 16 turns. Quartz tube is placed in the air gap between
yoke ends and inductor coils in order to prevent undesirable
contact between the melt and furnace parts. With out of
magnetic material teeth the position of EM levitated sample
is unstable and it is pushed towards the quartz tube wall
(Fig. 6, a). Because of that four magnetic teeth from FLUX-
TROL are introduced for redistribution of magnetic field and
stabilization of EM levitating sample (Fig. 6, b).
In the beginning of the calculation liquid aluminum drop
was given a spherical shape and zero velocity. It was placed a
few millimeters above its experimentally observed position.
The qualitative comparison between experiment photo
and picture of numerical model reveals a good agreement
for the droplet shape at a steady state (Fig. 7). The comparison
between our 3D calculation results, experimental
Fig. 3: 2D calculation results for molten aluminum free surface dynamics
in big industrial ICF, as well as typical meniscus shape comparison
to calculation [8]
measurements of droplet positions and 2D steady calculation
of O. Pesteanu are presented in Fig. 8.
It can be noticed that the droplet shapes obtained with
both models are in a good agreement with experiment.
Alternate current in inductor generates alternate magnetic
field that due to the great magnetic permeability of
ferrite is mainly concentrated in the yoke. In the air gap
region magnetic field lines spread and due to the skin effect
(δ EM = 1.55 mm) flow around electrically conductive aluminium
drop from one yoke end to another. In the regions
where magnetic field lines are separating at the surface of
the drop the minimum of Lorentz force is expected due
to the small magnetic field component parallel to free surface.
Meanwhile maximum of Lorentz force is expected at
the bottom of the drop due to the greater field intensity
and dominating field component along free surface. The
following Lorentz force distribution (Fig. 8) contributes to
the stretching of the drop along magnetic field lines. In
some time curvature radius of droplet free surface where
a) b) c)
Fig. 4: Geometry of E. C. Okress levitation melting furnace in a 3D model (a) and comparison between V. Bojarevics (b) and
simulation of ETP (c)
1-2014 heat processing
83

REPORTS
Research & Development
Fig. 5: Steady state free surface shape, Lorentz force (0-0.35 MN/m 3 , on the
left) and flow pattern (0-22 cm/s, on the right) calculated for EM levitation
of molten sample in E. C. Okress experimental setup for different
values of (a) - surface tension η, (b) - inductor effective current I ef
a)
Fig. 6: EM levitation of solid aluminum cylinder that touches quartz tube walls
in a single-frequency EM levitation melting setup without additional
magnetic material teeth (a) and numerical model of modified setup
with introduced magnetic material teeth (in green) and stabilized molten
aluminum droplet (b)
a)
Fig. 7: Qualitative comparison between experimentally observed [11] (a) and
numerically predicted (b) free surface shape of EM levitating drop in
the single frequency EM levitation device
b)
b)
magnetic field line separation takes place becomes
small enough and growing contribution of the surface
tension effects will stop the droplet stretching.
For the greater volumes of EM levitated droplets
the particular single-frequency horizontal EM field
configuration will contribute to the droplet shapes
that are significantly stretched along EM field lines. In
the meantime, the length of the droplet is limited due
to the diameter of the quartz tube, distance between
inductor coils or yoke ends. In order to increase the
EM levitated droplet weight, it is considered to install
additional orthogonal horizontal EM field [11]. 3D
numerical simulation of droplet (m = 30 g) flow and
free surface dynamics in two-frequency levitation
melting setup has been performed and a good agreement
with experiment has been obtained [12]. Using
the developed numerical approach the novel levitation
melting setup that meets conditions for stable
levitation of 1 kg of aluminum melt is being designed.
CONCLUSIONS
The new general approach for coupled 3D simulation
of liquid metal flow, free surface dynamics and
EM field is developed. It is adjusted for the case of
EM levitation and can be used with LES turbulence
approach. In the next step it is planned to supplement
the model with calculation of energy transfer
and crystallization.
The comparison of our calculation results to
experimental measurements and results of other
models for the steady state free surface in induction
furnaces and EM levitation melting setup, as well
as comparison of free surface oscillation period to
analytical estimation, revealed a good correlation
and approved accuracy of our model.
The new method for drip- and leakage-free EM levitation
melting of metallic samples with greater weights
and stabilized positions proposed by O. Pesteanu et. al.
has been validated by our numerical model.
Using the developed approach it is planned to
tailor the design of the novel levitation melting setup
and configuration of EM field in order to meet the
conditions for stable EM levitation of industrial-scale
molten metal charge and reproduce it in the laboratory
experiment.
ACKNOWLEDGEMENTS
Current research was performed with financial
support of the ESF project of the University of Latvia,
contract No. 2009/0138/1DP/1.1.2.1.2/09/IPIA/
VIAA/004. The authors wish to thank the German
Research Association (DFG) for supporting this study
under the Grant No. BA 3565/3-1.
84 heat processing 1-2014

Research & Development
REPORTS
The authors would like to acknowledge the great scientist
Prof. Ovidiu Pesteanu (*1945-†2012) for development
of the novel technology of EM levitation in horizontal field,
his contribution and support in this research and Dr. Valdis
Bojarevics for kindly sharing his simulation data of E. C.
Okress et. al. experiment.
LITERATURE
[1] Baptiste, L. et al. (2007): Electromagnetic levitation: A new technology
for high rate physical vapour deposition of coatings onto
metal strips. Surface & Coatings Technology, Vol. 202, 1189-1193
[2] Kirpo, M. Modelling of turbulence properties and particle
transport in recirculated flows. Ph.D. Thesis, University of Latvia,
Riga, 2008.
[3] Bojarevics, V., Harding, R., Pericleous, K., Wickins, M. (2004):
The development and experimental validation of a numerical
model of an induction skull melting furnace. Metallurgical
and Materials Transactions B, Vol. 35, 785-803
Fig. 8: 3D calculation results for the Lorentz force, flow pattern and
free surface shape in comparison to O. Pesteanu 2D calculation
and his experimental measurements
[4] Easter, S., Bojarevics, V., Pericleous, K. (2011): Numerical
modelling of liquid droplet dynamics in microgravity. Journal
of Physics: Conference Series, 327 012027
[5] Spitans S., Jakovics A., Baake E., Nacke B. (2013): Numerical
Modelling of Free Surface Dynamics of Melt in an Alternate
Electromagnetic Field. Part I. Implementation and verification
of model. Metallurgical and Materials Transactions B, Vol.
44 (3), 593-605
[6] Spitans S., Jakovics A., Baake E., Nacke B. (2012): Numerical
modelling of free surface dynamics of melt in an alternate electromagnetic
field. Journal of iron and steel research international,
Vol. 19, Suppl. 1/1, 531-535
[7] Westphal, E. (1996): Elektromagnetisches und thermisches
Verhalten des Kaltwand-Induktions-Tiegelofens. Dr-Ing. Dissertation,
Dusseldorf, 21(210)
[8] Hegewaldt, F., Buligins, L., Jakowitsch, A. (1993): Transient
bath surface bulging at energization of an induction-type
crucible furnace. Elektrowärme International, Vol. 1, 28-42
[9] Okress, E. C., Wroughton, D. M., Comenetz, G., Brace, P. H.,
Kelly, J. C. R. (1952): Electromagnetic Levitation of Solid and
Molten Metals. Journal of Applied Physics, Vol. 23, 545-552
[10] Pesteanu, O., Baake, E. (2011): The multicell VOF method for
free surface simu-lation of MHD flows. Part I: Mathematical
model and Part II: Experimental verifications and results. ISIJ
International, Vol. 51(5), 707-721
[11] Pesteanu, O., Baake, E. (2012): New Method and Devices for
Electromagnetic Drip and Leakage-Free Levitation Melting.
ISIJ International, Vol. 52(5), 937-938
[12] Baake, E., Spitans, S., Jakovics, A. (2013): New technology for
electromagnetic levitation melting of metals. In the Proceeding
of the International Conference on Heating by Electromagnetic
Sources, Padua, Italy, (addendum) 1-8
AUTHORS
Prof. Dr.-Ing. Egbert Baake
Institute for Electrotechnology
Leibniz Universität Hannover, Germany
Tel.: +49 / (0)511/762-3248
baake@etp.uni-hannover.de
Prof. Dr. Phys. Andris Jakovics
Laboratory for Mathematical Modelling of
Environmental and Technological Processes
University of Latvia, Latvia
Tel.: +371 / (0)67033780
andris.jakovics@lu.lv
MSc. Phys. Sergejs Spitans
Institute for Electrotechnology
Leibniz Universität Hannover, Germany
Tel.: +49 / (0)511/762-5116
spitans@etp.uni-hannover.de
1-2014 heat processing
85

Handbook of
refractory Materials
www.vulkan-verlag.de
Order now!
design | Properties | testings
This new edition of the Handbook of Refractory Materials has been completely
revised, expanded and appears in a compact format.
readers obtain an extensive and detailed overview focusing on design,
properties, calculations, terminology and testing of refractory materials
thus providing important information for your daily work. the appendix
was supplemented by following suggestions of readers. Consequently,
the handbook‘s usability was enhanced even further. With the great
amount of information this compact book is a necessity for professional
working in the refractory material or thermal process sectors. the e-book
offers even more flexibility while travelling.
editors: G. routschka / H. Wuthnow
4 th edition 2012, 344 pages, with additional information and e-book
on DVD, hardcover
Vulkan-Verlag GmbH, Huyssenallee 52-56, 45128 Essen
knowledge for tHe
future
order now by fax: +49 201 / 82002-34 or send in a letter
Deutscher Industrieverlag GmbH | Arnulfstr. 124 | 80636 München
Yes, I place a firm order for the technical book. Please send me
— copies of the Handbook of Refractory Materials plus DVD ROM.
4 th edition 2012 (ISBN: 978-3-8027-3162-4)
at the price of € 100,- (plus postage and packing extra)
Company/institution
first name and surname of recipient
Street/P.o. Box, No.
Country, Postcode, town
reply / Antwort
Vulkan-Verlag GmbH
Versandbuchhandlung
Postfach 10 39 62
45039 Essen
GERMANY
Phone
e-mail
Line of business
fax
Please note: According to German law this request may be withdrawn within 14 days after order date in writing
to Vulkan Verlag GmbH, Versandbuchhandlung, Postfach 10 39 62, 45039 essen, Germany.
In order to accomplish your request and for communication purposes your personal data are being recorded and stored.
It is approved that this data may also be used in commercial ways by mail, by phone, by fax, by email, none.
this approval may be withdrawn at any time.
✘
Date, signature
PAHBrM2013

Edition 9
FOCUS ON
”We want to excel
in everything we do”
Dr.-Ing. Rolf Terjung is CEO of the Graphite Materials GmbH. In this interview with
heat processing he talks about the future of the energy industry and technological
challenges, revealing his own personal energy-saving achievement.
Read all
interviews online
The energy mix of the future: Do you dare make a
prediction?
Terjung: At the moment, and definitely in the near future as
well, energy sources are competing against each other. At
present, I do not believe that a single energy source will dominate.
However, it seems certain that the world will continue
to depend on fossil energy sources for
a long time to come. I think it really
bizarre that, in Germany in particular,
gas as energy source has an extremely
negative image, despite the fact that
gas process technology has become
highly efficient over the last few years.
Germany in the year 2020: How
will people’s daily lives have altered
as a result of the changes in the energy sector?
Which fuel will they use in their cars? How will they
heat their homes? How will they produce light? Show
us a picture of the future!
Terjung: The German energy transition will have increased
the price of electricity and water considerably. If people
have to dip into their wallets, they become acutely aware
of any changes. This will result in a more economical use
of resources. In most cases, we will still be fuelling our cars
with diesel and petrol. However, I think that gas will be more
important than it is today, not least as a result of the gas
resources that have recently been discovered in Iraq and
other countries. Due to the heated public discussions that
are currently taking place, I am unable to comment on socalled
“fracking”, which will continue to produce large and
convenient quantities of gas in the USA.
Solar power, wind, water, geothermal energy etc.: Which
of the renewable energy sources do you consider to have
the brightest future?
Terjung: It is difficult to say. With regard to Germany, each
single source more or less has a geographical advantage
over the others. The answer probably lies in a sound mixture
of them all. Our current problem is actually the insular
structure of the renewable energy sources that are not
interconnected.
In which of the technologies that are currently being developed
would you invest today?
Terjung: In the generation of our
“High energy prices
have shed new light
on the subject of
competitiveness.”
own electricity. Within the context
of the current legislation of
the German Renewable Energy
Sources Act (EEG), the energy
transition will lead to a further
increase in energy prices. Our
world is particularly dependent
on electrical energy. To regulate
the price, we will invest in
the most modern and expedient generation of our own
electricity. With regard to our products, we are investing
in energy-saving furnace insulation and charging device
systems.
How do you assess the future importance of fossil fuels
such as oil, coal and gas?
Terjung: Fossil fuels will largely continue to supply people
with energy. I am in no doubt about that.
Speaking of the energy transition: Which changes have
to be realised on both a political and global-political level,
as well as on a social and ecological level, so that we
can actually speak about a transition?
Terjung: The energy transition is an entirely German
invention. At the moment, no other nation in the world
is pushing an energy transition, i.e. the move away from
nuclear energy production. Even in Europe, Germany is
on its own as far as the energy transition is concerned
and our neighbours, as well as the rest of the world, are
watching developments in Germany with astonishment.
Not even Japan has declared war on nuclear energy,
despite the Fukushima disaster. This is closely related to
1-2014 heat processing
87

FOCUS ON Edition 9
RESUME
Rolf Terjung
Education:
Graduation:
Career
Academic studies: RWTH Aachen University
Institute of Ceramic Components, RWTH
Aachen University
1994 – 2000: Fa. Henschke GmbH, Internationale Industrievertretungen
2000 – 2002: Fa. Dr.-Ing. Rolf Terjung Graphite Materials
Service_Handel_Vertrieb
2003 – today: Graphite Materials GmbH, Founder and CEO
economical considerations and lobbyism. In Germany, the different
parties have, for a long time, kept us informed in great detail.
In my view, society has really scrutinised this issue. In general, I
am convinced that an energy transition is possible in Germany
if the aims are realised whilst maintaining realistic standards and
including the necessary expertise (research, associations, industry).
Unfortunately, the German energy transition was rushed due to
the shock of the Fukushima disaster and, as a result, has become
one of the great challenges facing Germany. I am convinced that
Germany will succeed.
In this context, what do you want from the federal government?
Terjung: A fundamental reform of the EEG is essential, regardless of
lobbyists, in order to keep, for example, electricity affordable. More
than ever, it has to promote research and innovation.
Renewable energies are facing at least two problems: the lack of
infrastructure and the establishment’s inertia with regard to conventional
forms of energy. Will this change in the near future?
Terjung: I really do hope so. As an entrepreneur, I believe that it has
to change, otherwise the current government will ruin Germany as a
place for industry. I am certain that the government is fully aware of
the seriousness of the situation and will act in the near future. However,
we need a concerted effort rather than piecemeal solutions.
Irrespective of the various forms of energy and technology, many
people think that “energy efficiency” is the clue to the energy mystery
of the future. What are your views on that? What do you think
is the most important development in this respect?
Terjung: I agree. I think that, as far as efficiency is concerned, we
are just at the beginning. Engineering sciences will continue to be
very successful. Energy prices, which are considered “expensive”, will
create a deep awareness for energy in society. We are dealing with
thermal insulation for vacuum and inert gas furnaces. We note that,
especially since 2013, furnace manufacturers and operators regard
energy efficiency as their number-one priority. Technical solutions
that were known before but that were rejected for reasons of cost
are now experiencing a renaissance and are being developed further.
The energy saving by far exceeds the additional costs of innovative
insulation. According to our experience, the payback period amounts
to less than 12 months.
What is your position with regard to the heat treatment sector?
Terjung: The heat treatment industry, including furnace manufacturers,
is one of our main customers. We offer graphite components
(e.g. heaters), furnace insulation and CFC components
(e.g. charging devices). With regard to energy efficiency, I believe
that charging systems made of CFC will gain a considerable share
of the market. The specific solidity (solidity compared to material
density) enables significant mass reductions compared to metal
devices with a comparable stiffness. This saves energy and the
process is accelerated.
88 heat processing 1-2014

Edition 9
FOCUS ON
What do you think of the development with regard to
increasing efficiency?
Terjung: High energy prices have shed new light on the
subject of competitiveness. The heat treatment industry in
Germany is forced to make increasing efficiency one of the
main concerns. Speaking in racing terms: Anyone wanting
to be a world leader has to make increasing efficiency a
continuous improvement project.
How do you think energy consumption will change?
Terjung: It will increase. Progress will continue to saturate
the emerging markets. South America, India, China and
Africa want to further improve their standard of living by
means of industrialisation. National governments bear
the heavy responsibility of enabling change to take place
in an environmentally acceptable way on a broad social
level. Unfortunately, the results of the world climate conferences
show that national egoism and profit-seeking cast a
shadow over rationality and science.
What will your company’s most important innovation/
project be?
Terjung: We focus on three projects that could be described
as “innovative” from our point of view:
The production of furnace insulation based on carbon fibres
(soft and hard felts) in modular construction for standard
semi-finished product formats. CFC charging device systems
with the lowest possible shading for the low-pressure carburisation
of outer layers in a standard design whilst providing
the highest possible component flexibility for customers.
CFC charging device systems with a durable local coating for
thermal processes above 1,050 °C (vacuum, inert gas) that
prevent carbon diffusion in contact with metal components.
Which challenges are you facing (in terms of economy,
technology and society)?
Terjung: The coalition agreement of the federal government
leaves a lot to be desired as far as support for
the economy is concerned. I see a political risk that the
economy no longer has the necessary standing in order to
maintain Germany’s high level of economic achievement,
which is highly regarded the world over.
In terms of technology, we are a niche market player, which
means that innovation is always a challenge. In this respect,
we are particularly affected by the skills shortage.
Society’s actual attitude towards the notion of achievement
gives me food for thought. The German welfare
state has created a dense social network that promotes
a mentality of “I take what I am entitled to”. It is no
coincidence that pupils state career aspirations such
as welfare recipient. In work-life balance discussions,
politics and society are asked to show people how to
successfully combine family, work, lifelong learning
and performance.
What has been the impact
of the enlargement of
the EU and globalisation
on your business?
Terjung: It has
been a positive
impact. We are able
to access new markets
and possibly
to attract skilled
experts to our
company.
“I am especially proud
that employee turnover
is very low.”
1-2014 heat processing
89

FOCUS ON Edition 9
How important is a brand name for the success of a product
in the industrial field?
Terjung: A brand name is important but not essential. With
a brand name, the manufacturer makes a commitment with
regard to innovation, reliability and confidence. In turn, he
is rewarded with reputation and economic success.
Was the skills shortage the reason for the delay in or lack
of developments in your company in Germany?
Terjung: No.
What would you like to change in your company?
Terjung: At the moment, nothing. In 2013, we started a
reorganisation that is already bearing fruit. Our employees
broadly agree with the changes. An increase in quality
and productivity and meeting deadlines are rewarded by
customer satisfaction.
What is the importance of expansion abroad for your
company?
Terjung: We try to position our core competences in different
markets on as broad a basis as possible whilst maintaining
our high performance. Sometimes, “less” is “more”.
We want to excel in everything we do.
Is your company open to renewable energies?
Terjung: Absolutely. Since April 2012, we have only been
purchasing certified green electricity. Furthermore, we
supply customers in the field of renewable energies. In
order to effectively reduce the share of nuclear and fossil
energies, renewable energy sources have to be taken into
account when drawing an energy balance.
Does your company already use renewable energies?
Terjung: As I have already said, in our company, we only
use electricity from renewable sources. In order to increase
our energy efficiency, we consequently use process heat
for generating hot water and for heating the building.
How open is your company to new technologies?
Terjung: In our daily business, we uphold the philosophy
that “the best idea wins”. This certainly includes new technologies.
We are in no doubt that innovation is possible
precisely because, when working on our various projects,
we question absolutely everything. This enables us to
develop new ideas.
How much does your company invest each year?
Terjung: To give you an approximate figure: € 250,000.
What was/is the greatest way you save energy as a private
individual?
Terjung: I ride my bike as often as possible. When driving
a car, I try to travel at a moderate speed. We use energysaving
lightbulbs and LED lights wherever possible. I cannot
single out one particular measure. It is the sum of all
measures that saves electricity, water and gas.
How would you characterise your contact with
employees?
Terjung: Cooperative, and I provide clear guidance by
setting targets.
What is it about you that your employees particularly
value?
Terjung: I couldn’t say for sure. I am especially proud that
employee turnover is very low.
Which moral values are particularly important for you
at the moment?
Terjung: Respect, trust, friendship and reliability. In day-today
work, we place particular importance on the “Hanseatic
merchant values”.
How do you manage to have time to yourself and not be
carried away by internal and external challenges?
Terjung: I have realised that my life is finite. Apart from my
work, I want to spend as much time as possible with my
family and friends. Every day, there are shocking examples
showing us that everything can change “tomorrow”. That
is why I am determined to live every day to the full and to
separate my private and business life.
Do you have any role models?
Terjung: My father who, unfortunately, passed away too
early. As a businessman, I take my hat off to Dr. Jürgen
90 heat processing 1-2014

Edition 9
FOCUS ON
Großmann who has achieved tremendous success for
Georgsmarienhütte during a difficult time for the steel
industry.
How were you brought up?
Terjung: With affection and with values that I still uphold
today and that I pass on to our sons. I was given great freedom
but also clear limits that I had to respect. My parents gave me
a healthy self-confidence and a good start in life.
How should children be raised today?
Terjung: Everyone has to answer this question for themselves.
As far as I’m concerned, values such as respect, punctuality,
confidence and reliability are still important today in order to
give children both the necessary boundaries and the necessary
freedom. Children have to gain their own experience and
also know that they are welcome at home. We are grateful that
we still talk every day to our sons, aged 16 and 18.
Which good cause would you stand for?
Terjung: For freedom.
What do you wish for the next generation?
Terjung: A healthy feeling for life, both with and without
new media (smartphones, internet, WhatsApp, etc.).
What is your philosophy in life?
Terjung: Activity. I am always curious. I hate being bored,
both in my private and my work life.
In your opinion, what was the most important invention
of the 20 th century?
Terjung: The dishwasher. Doing the dishes is terrible.
Which character traits are important to you?
Terjung: Generosity, authenticity and reliability.
How would you describe yourself in three words?
Terjung: Generous, ambitious, authentic.
Whose career has impressed you most?
Terjung: Michael Schumacher's.
What advice would you give the next generation?
Terjung: Save the environment because human beings
can only relax in nature.
What has influenced you most?
Terjung: My parents’ belief in me. This experience is invaluable
and is able to move mountains.
What could you not live without?
Terjung: My family.
If you could choose, which would be your preferred profession?
Terjung: I have found my vocation: engineer.
Where do you expect to be in 10 years’ time?
Terjung: I’d like to hold an honorary position outside the
company where I can contribute my experience to the
well-being of others.
For you, what is the meaning of life?
Terjung: Being at ease with oneself. The road to achieving this
is marked by many curves and experiences. Not taking yourself
too seriously and also taking a critical look at yourself help you
to put your life into perspective. You then realise that you are
actually quite lucky. You are content and experience moments
of happiness. I believe that you cannot ask for more.
If you had the choice, what would you do differently
in life?
Terjung: Nothing. I wouldn’t change anything.
What are your hopes for the world?
Terjung: Peace, mutual understanding and less greed.
Which country would you like to live in?
Terjung: Germany, but in a sunny part of Germany. And
that is exactly where I live.
Which country would you emigrate to?
Terjung: I am interested in Australia.
Thank you for this interview!
1-2014 heat processing
91

Handbook of
thermoprocessing
technologies
Volume 1: fundamentals | Processes | Calculations
This Handbook provides a detailed overview of the entire thermoprocessing
sector, structured on practical criteria, and will be of particular assistance
to manufacturers and users of thermoprocessing equipment.
In europe thermoprocessing is the third largest energy consumption
sector with a very diversified and complex structure. therefore it is split
into a large number of subdivisions, each having a high importance
for the industrial economy. Accordingly we find the application knowhow
for the design and the execution of respective equipment represented
by a multitude of small but very specialized companies and their experts.
So this second edition is based on the contribution of many highly
experienced engineers working in this fi eld. the book’s main intention is
the presentation of practical thermal processing for the improvement of
materials and parts in industrial application. Additionally it offers a summary
of respective thermal and material science fundamentals. further it
covers the basic fuel-related and electrical engineering knowledge and
design aspects, components and safety requirements for the necessary
heating installations.
editors: f. Beneke, B. Nacke, H. Pfeifer
2nd edition 2012, 680 pages with additional media files and
e-book on DVD, hardcover
www.vulkan-verlag.de
Jetzt bestellen!
Vulkan-Verlag GmbH, Huyssenallee 52-56, 45128 Essen
knowledge for tHe
future
order now by fax: +49 201 / 82002-34 or send in a letter
Deutscher Industrieverlag GmbH | Arnulfstr. 124 | 80636 München
Yes, I place a firm order for the technical book. Please send
— copies of Handbook of Thermoprocessing Technologies 2nd edition 2012
(ISBN: 978-3-8027-2966-9) at the price of € 200,- (plus postage and packing)
— copies of Handbook of Thermoprocessing Technologies 2nd edition 2012
(ISBN: 978-3-8027-2966-9) at the special price of € 180,- (plus postage and packing)
for subscribers of heat processing
Company/institution
first name and surname of recipient
Street/P.o. Box, No.
Country, Postcode, town
reply / Antwort
Vulkan Verlag GmbH
Versandbuchhandlung
Postfach 10 39 62
45039 Essen
GERMANY
Phone
e-mail
Line of business
fax
Please note: According to German law this request may be withdrawn within 14 days after order date in writing
to Vulkan Verlag GmbH, Versandbuchhandlung, Postfach 10 39 62, 45039 essen, Germany.
In order to accomplish your request and for communication purposes your personal data are being recorded and stored.
It is approved that this data may also be used in commercial ways by mail, by phone, by fax, by email, none.
this approval may be withdrawn at any time.
✘
Date, signature
PAHBtt2013

Edition 5
PROFILE+
This is where we focus in regular intervals on the main institutions and organisations active in
the field of thermoprocessing technology. This issue spotlights the International Flame Research
Foundation (IFRF).
International Flame Research Foundation (IFRF)
IFRF is a research and networking hub for
the global combustion and energy community.
Originating at IJmuiden, the Netherlands
in 1948, the Foundation serves an
established and growing worldwide network
of combustion or energy oriented
industrial and academic organisations
including the full spectrum of:
■■
■■
■■
■■
fired heater equipment and energy suppliers
and end users,
technology developers,
research institutes,
policy makers.
Since 2007, IFRF has been headquartered
in Livorno, Italy, adjacent to the experimental
facilities of European utility giant Enel
(Fig. 1).
The mission of IFRF is to advance
applied combustion research and to promote
cooperation and information transfer
throughout the international combustion
and energy arena. As such, the IFRF team
at Livorno works primarily to perform
research, to facilitate access to research
capabilities and expertise worldwide, and
to disseminate information. An actively
managed website is key to all of these tasks,
and also to a further vital aspect of the work
at IFRF headquarters – coordination of the
IFRF membership scheme which is at the
heart of the network.
HISTORY
In the early days, IFRF was an industrially
based co-operative research organisation
for an international steel industry
consortium, and designed handbooks
for the steam atomised, heavy fuel oil
lances used in the open hearth furnaces
of France, the Netherlands and the United
Kingdom. This focus was expanded
– initially in terms of heat transfer by
radiation, and subsequently in the field
of flame aerodynamics and chemistry,
to encompass flames from other fuels,
to be applied in alternative combustion
chambers, and in other industries.
The book “Spirit of IJmuiden: Fifty
years of the IFRF, 1948-1998” published
by Roman Weber, describes the research
themes which have characterized successive
decades of IFRF activity. Whilst the sixties
belonged to combustion aerodynamics,
the seventies were the period of NO X
and mathematical modelling – IFRF also
began to contract research at this time. In
the eighties, the focus was on coal combustion
research and the associated near
field aerodynamics; research during the
nineties typically concerned combustion
system scaling and numerical simulations
– and this was also the time when IFRF
developed a reputation for its specialised
research facilities.
CURRENT RESEARCH
Subsequent to its move from IJmuiden to
Livorno, Italy in 2006, IFRF has maintained
the tradition of performing experimental
and modelling research in-house (Fig. 2)
to enhance its own database and develop
methodologies and protocols for use by
member organisations. Similarly, IFRF has
continued to contract research for public
and private organisations and to develop,
manufacture, sell and test measurement
probes and systems.
Fig. 1: Enel Research Facility in Livorno
Fig. 2: IFRF investigators at work
1-2014 heat processing
93

PROFILE+ Edition 5
Fig. 3: Isothermal Plug Flow Reactor (IPFR)
Areas of focus in the current research
agenda include:
■■
oxy-combustion studies,
■■
thermochemical conversion of 2 nd generation
biofuels,
■■
development of new instrumentation
and methodologies,
■■
solid fuel combustion characterisation,
■■
validation of combustion modelling for
practical combustion systems.
This article will concentrate on the first
two areas mentioned, oxy-combustion
studies and thermochemical conversion
of 2 nd generation biofuels, both associated
with EU funded projects, and on the third,
development of new instrumentation and
methodologies, which represents a further
source of funding for IFRF activities.
OXY-COMBUSTION STUDIES
Conceptually the experimental programme
is divided into two phases:
■■
experiments with existing low-NO X
burners in order to characterize the
combustion process with oxygen and
recycled flue gas, with both natural gas
and coal as fuels, and to produce data
sets for modelling validation;
■■
tests with new oxy-coal burners aimed
at verifying the criteria adopted in the
design phase and developing a better
understanding of oxy-coal burner
design.
IFRF’s involvement in the EU funded
RELCOM project is facilitating much of
the work required in the second phase
described above. RELCOM (Reliable and
Efficient Combustion of Oxygen/Coal/
Recycled Flue Gas Mixtures) has a four
year lifespan, was launched in late 2011,
and is being undertaken by a consortium
of higher education institutions, research
centres and industrial partners. As might
be expected, the partners are required
to perform a series of applied research,
development and demonstration activities
involving both experimental studies
and modelling work.
Full information is available on the REL-
COM website www.relcomeu.com which
is run and managed by an IFRF staffer as
part of the dissemination work package.
THERMOCHEMICAL CONVER-
SION OF 2 ND GENERATION
BIOFUELS
BRISK (Biomass Research Infrastructure for
Sharing Knowledge) is an initiative from
the European Union’s 7 th Framework Programme
and aims to develop a European
research infrastructure for thermochemical
biomass conversion.
BRISK offers three principle activities:
Transnational Access; Joint Research; Networking.
Transnational Access enables
European organisations, including those
outside the project partnership, to send
their researchers to undertake experiments
on any of the laboratories offering access
to test facilities. The cost of running the
rigs for these activities is met by the EU’s
BRISK cofunding.
For BRISK, IFRF offers access to its Isothermal
Plug Flow Reactor (IPFR) (Fig. 3),
and also to a tar cracking unit and 200 kW
downdraft fixed bed gasifier which are the
property of the University of Pisa.
BRISK funding has allowed IFRF to
complete the development of an online
searchable database of European test rigs
initiated as part of the European Flame
Research Initiative (EFRI). The scope has
been extended to include all aspects of
fuels processing, adding for example gasification,
pyrolysis, cleaning, and upgrading.
The database can be viewed on the IFRF
website and the dedicated BRISK website
is www.briskeu.com
Fig. 4: IFRF manufactured suction pyrometer in action
DEVELOPMENT OF NEW
INSTRUMENTATION AND
METHODOLOGIES
Developing new in-flame measurement
instruments and methodologies has led
IFRF to re-establish its probe manufacturing
capability and also to the study of optical
diagnostics. A new quartz quenched
94 heat processing 1-2014

Edition 5
PROFILE+
Fig. 5: Measurements in FOSPER 3 MW furnace
Fig. 6: FOSPER - window open during start-up
sampling probe/FTIR analyser for in-flame
chemical species measurement has also
been developed and tested.
Probes which may be ordered from IFRF
for manufacture include suction pyrometers
(Fig. 4), gas and solid sampling probes,
total heat flux radiometers and ellipsoidal
radiometers.
EXPERIMENTAL FACILITIES
Through formal agreements with Enel
and the University of Pisa, IFRF has access
to the Enel Livorno research facilities and
those of the University of Pisa at San Piero.
These facilities are the stage for the IFRF’s
experimental work on semi-industrial and
pilot-scale furnaces and reactors. They are
also available to third parties who may
award private research contracts to IFRF.
Key facilities inside the Enel plant
include the 3 MW FOSPER Furnace (Fig.
5 and 6), a replica of the former IFRF Furnace
#1 at IJmuiden, used to perform a
broad range of combustion tests, and the
Isothermal Plug Flow Reactor (IPFR), an
entrained plug flow reactor used to represent
conditions found in full scale applications.
Heating rates of the order 10 4 -10 5 K/s
are easily obtained as well as typical gas
temperatures and composition.
The IPFR was rebuilt and re-commissioned
in 2010, and upgraded to simulate
oxy/solid fuel conditions. The facility is
now also fully operational for investigating
the formation and fate of aerosols
when firing coal and biomass blends in
the presence of sulphur oxides. This is the
result of the facility being equipped with
a special chimney to reproduce temperature-time
histories in the fouling region,
and also with an Electrical Low Pressure
Impactor Dekati for aerosol quantitative
assessment.
The University of Pisa facilities include
a bio-ethanol plant, the 200 kW downdraft
fixed bed gasifier mentioned above,
and a vegetable oil treatment and transesterification
plant.
NETWORKING
From a networking perspective, IFRF is a
natural conduit to the international combustion
community. In more than 60 years
of research activity the Foundation has
established close links within the global
combustion arena and is well positioned
to capitalize on these links for the benefit
of IFRF members.
For its members, access to the IFRF network
is facilitated both online and face to
face, the latter via technical events, conferences,
and training courses organized in
cooperation with an interconnected grid of
IFRF national committees around the world.
Topic Orientated Technical Meetings
(TOTeMs) represent a good portion of the
technical meetings organized by IFRF. The
TOTeM concept was originally conceived as
an information gathering method to ensure
the ongoing renewal of the IFRF research
agenda, and has been applied to 39 meetings
since its adoption in 1989.
Typically a TOTeM gathers delegates and
invited guests around a one and a half day
event where the discussion is focused on a
topic of interest rather than on a technical
discipline. The meeting is chaired by a recognized
expert who coordinates input on
the state of the art from keynote speakers,
followed by presentations from individuals
describing their current activity in the
topic area of interest. On the second day,
via a round table discussion, the technology
gaps and research needs within the
topic area are identified.
The end product of each TOTeM is a
summary paper which describes the state
of the art in the topic under discussion,
the current situation in practice and the
research requirements. This paper is integrated
into the process of IFRF triennial
research planning.
In addition to organizing technical
events, the national committees also
administer the IFRF membership scheme
which enables individuals and organisations
to network locally while enjoying the
benefits offered from IFRF headquarters at
Livorno. These include:
■■
■■
■■
access to current research reports and
conference notes stored on the IFRF
website,
commissioning tests and instrument
manufacture at reduced rates,
attendance at experimental trials,
1-2014 heat processing
95

PROFILE+ Edition 5
■■
discounted entry into conferences,
workshops and training opportunities.
Online, IFRF’s networking efforts find one
of their most important outlets in the
European Facilities Database, a searchable,
publically available resource which lists and
describes the combustion and biofuels test
rigs of some 50 European industrial and
research organisations. IFRF is committed
to promoting cooperation and connection
within the global combustion and energy
community. As such, the long-term objective
is to expand the resource beyond its
European origins and to create an integrated
network of combustion facilities
worldwide.
Other online networking tools offered
by IFRF to its members include the Members
Exchange, a private and secure virtual
community, a number of forums dedicated
to specific research topics, and a LinkedIn
discussion group.
INFORMATION DISSEMINATION
IFRF employs a variety of media to make
available to combustion practitioners the
information generated from its research
and networking activities. These include
an online, searchable archive of technical
reports, a rich resource of presentations
and papers from conferences, workshops
and technical meetings downloadable
directly from the IFRF website, and the IFRF
Solid Fuel database, a collection of devolatilisation,
char combustion and nitrogen
release data on a variety of coals and biomasses
tested in the IPFR (Isothermal Plug
Flow Reactor).
In addition, and also for the general
public, IFRF produces a biweekly online
newsletter “Monday Night Mail”, featuring a
wrap-up of international combustion news,
and also runs “Industrial Combustion”, an
online peer-reviewed journal dedicated to
publishing the best research on the practical
and theoretical aspects of combustion
science in industrial applications.
Contact:
IFRF:
Via Salvatore Orlando 5
57123 Livorno, Italy
Email: info@ifrf.net
Website: www.ifrf.net
Handbook of Aluminium Recycling
Mechanical Preparation | Metallurgical Processing |
Heat Treatment
Order at:
Tel.: +49 201 82002-14
Fax: +49 201 82002-34
bestellung@vulkan-verlag.de
The Handbook has proven to be helpful to plant designers and operators
for engineering and production of aluminium recycling plants. The book
deals with aluminium as material and its recovery from bauxite, the
various process steps and procedures, melting and casting plants, metal
treatment facilities, provisions and equipment for environmental control
and workforce safety, cold and hot recycling of aluminium including
scrap preparation and remelting, operation and plant management. Due
to more and more stringent regulations for environmental control and
fuel efficiency as well as quality requirements sections about salt slag
recycling, oxy-fuel heating and heat treatment processes are now incorporated
in the new edition. The reader is thus provided with a detailed
overview of the technology of aluminium recycling.
Editor: C. Schmitz
2 nd edition 2013, approx. 500 pages in colour, with interactive eBook (online read access),
hardcover
ISBN: 978-3-8027-2970-6
€ 130,00
Order now!
KNOWLEDGE FOR THE
FUTURE

TECHNOLOGY IN PRACTICE
Technical monitoring in ene.field – Europe’s project for micro
CHP technology
In late September 2012, 27 partners gathered
in Brussels to kick off an ambitious
project: namely Europe’s largest ever demonstration
and investigation project on
the latest fuel cell micro combined heat
and power technology. Now ene.field celebrated
its first anniversary and the first
fuel cell units are installed and running in
single family homes – time to have a closer
look at the project in general and at the
monitoring strategies within the project.
The quite large consortium consists of
nine European manufacturers of stationary
fuel cell micro CHP who are either very
close to market entry or have begun selling
their products already. Four large utility
partners open up the market for this
thrilling new technology and help finding
suitable field trial locations. The consortium
is then rounded up with European energy
institutes who will guarantee the scientific
correctness of the field trials. The results
of their analysis work will push forward
the further development of micro CHP for
smart homes and will take influence on
policy making as well as technical codes
and standards.
It is the ambitious goal of this five year
project to install close to 1,000 stationary
fuel cell heating systems in homes across
12 European member states. The systems
vary in their electrical output from 300 W to
5 kW. Their thermal output is always fitted
to the size of the building they are installed
at to guarantee non-stop and adequate
heat delivery. All systems have in common
that they contribute to European energy
savings and CO 2 -reductions goals at a very
high level of comfort for the end user. That
is why the comparison with other existing
CHP technology is not avoided in the project.
Fuel cell micro CHP can offer electricity
production and heating at high efficiencies
and does not even have to be noticed
inside the household by the user – to the
contrary of other comparable technologies.
Nevertheless a project of this size is
needed to demonstrate the potential of
fuel cell micro CHP, to localize markets and
segments, to identify barriers and to build
up supply chains to gear up production.
After many years of development there is
still a public reservation towards fuel cell
micro CHP. New technologies sometimes
find their way quite easily to their markets
like seen with smart phones and navigation
devices. But speaking of heating systems,
people become very suspicious due to
the fact of intense loss of comfort in case
of technical error. The project will help to
reduce such understandable but unnecessary
suspicions since the heating part of
fuel cell micro CHP is as save as a common
condensing boiler.
Intense scientific analysis can only be
performed with the right dataset at hand.
DBI – Gastechnologisches Institut gGmbH
Freiberg is the leader of the data collection
work package and responsible to gather
performance data of the trial units as well
as energy data of the households that take
part in the field test. Like in many other
monitoring jobs, DBI has performed the
technical analysis of plant performance and
energy balance of environment is part of
the monitoring package. In this case performance
behaviour is additionally linked to
geographical and meteorological inputs to
find the impacts of different climate zones
on the technology. Up to ten meters and
sensors constantly measure the physical
condition of the fuel cells and the building.
They report every 15 minutes to a data collection
box that is connected via a secure
tunnel with the data base servers at DBI.
Special monitoring software checks the
incoming data points towards plausibility
and consistency. The data collection box
at the trial locations can store data more
than two months and transfer missing data
caused by connection errors once internet
connections are running again. That gives
enough back-up time to save vital field data
and to transfer it to the data base server.
Since many competing manufacturers
have found their way in partnership in the
project, it is a matter of course that the delicate
field data is subject to privacy protection.
A special clean room environment
anonymizes and aggregates incoming data
before leaving DBI and their partners in
the data collection work package towards
other analysis institutes. It is extremely
important to erase retraceability from the
datasets to protect the right of privacy of
the end customer as well as the economic
interests of the manufacturers. At the end
of the project the partners in the data collection
work package will present a database
with performance data and energy
balance data of 1,000 different buildings
across Europe as a starting point for further
scientific investigations. The analysis done
in the project will be a vital part to further
adapt the today existing fuel cell micro CHP
technology to the real needs of real people.
The next steps in the project are to
increase the number of installations
through existing contracts and to hold
regional information workshops to increase
the level of awareness towards ene.field. It
is at this stage still possible for new utility
partners to get involved in the field trials
and to get to know the different fuel cell
systems within ene.field.
The ene.field project receives funding
from the European Union’s Seventh
Framework Programme (FP7/2007-2013) for
the Fuel Cells and Hydrogen Joint Technology
Initiative under grant agreement
no. 303462. For further information on the
project please visit the project’s homepage:
www.enefield.eu
Author:
Bert Otto
Contact:
Frank Erler
DBI – Gastechnologisches Institut gGmbH
Freiberg
Halsbrücker Straße 34
09599 Freiberg, Germany
Tel.: +49 (0) 3731 / 4195-324
frank.erler@dbi-gti.de
www.dbi-gti.de
1-2014 heat processing
97

PRODUCTS & SERVICES
Precision fine casting units for high melting alloys
Induction heated precision fine casting
machine for aerospace, medical engineering,
industrial parts and watch-, jewellery
industry: Supercast and Titancast
for castings up to 4,0 kg. Also for element
determination in recycling industry / sample
preparation for spectroscopy / cross
sectional samples etc.
A sophisticated medium frequency
technology allows melting and casting
metals in a very short time by centrifugal
casting process. A remarkable feature of
this unit is the high melting capacity at low
energy consumption. Furthermore, it is
also secured that due to the eddy currents
of induction heating, metals and alloys
can be mixed thoroughly and therefore,
are of continuous and reproducible quality.
This is not possible with any other
melting process. Easy to operate due to
modern S7- control with touch panel. All
systems are available in vacuum version
which enables to cast under air, inert gas,
vacuum or vacuum with inert gas purging.
Comprehensive accessories: e.g. optical
temperature measuring unit, water circulation
cooling, ceramic crucibles and casting
moulds are available.
The casting capacities of the Supercast
are (app.): Titan 2,000 g, TiAl 1,800 g,
Platinum 2,000 g, Palladium 3,000 g, Gold
4,000 g, Silver 3,500 g, Copper 3,000 g,
Bronze 3,000 g, Brass 3,000 g, Stainless steel
3,500 g, Fe/Ni/Cr 4,000 g, CrNi-Steel 3,500 g,
Cr/Co 3,500 g.
In 2014, the Supercast furnace will also
be available with cold-wall-crucible for
material quantities up to 2 kg (e.g. Ti). Due
to contactless melting in a water-cooled
copper crucibles, a reaction, pollution of
the melt with crucible material, will be
prevented.
Linn High Therm GmbH
www.linn.de
Analog signal processing with strain gauge amplifier
Müller Industrie-Elektronik offers the
proven analog strain gauge amplifier
ALM-HD as relaunched and extended
version ALM HD2 and in a new outfit in
the measurement device group for analog
signal processing. The user-friendly operation
has been maintained as well as the
adjustment of the input sensitivity
(0.1 mV/V to 4 mV/V) selectable by
DIP-switches. Furthermore, the new
analogue measuring amplifier ALM-
HD2 also factory pre-configured is
available. In the new version as an
option, two adjustable limit value
switches are integrated as potentialfree
changeover contacts. As input
signal up to four resistance strain
gauge sensors can be connected
parallel in full bridges with 350 ohms,
which can be evaluated as sum signal.
The output signal of the ALM-
HD2 offers a switchable analog output 0
(4) to +/- 20 mA or 0 (2) to +/- 10 V. The
sensor supply voltage is (4 to 14 V) adjustable.
The housing material is in the new
version of robust and durable plastic (ASA
757G Luran S).Thus, the new analog measurement
amplifier is now also suitable for
long-term use in the shipping industry, for
example, in rough seawater environment
and wherever with corresponding receivers
a strain gauge force measurement technique
is required.
As a specialist for industrial measurement
and control technology, Müller Industrie-Elektronik
offers in addition to analog
and digital strain gauge measuring amplifiers
all other equipment components for
the whole strain gauge measuring chain.
Starting at the force sensor as a transducer
on measuring and summing up amplifier
up to the display and evaluation electroniceither
as metrological overall solution with
individual components or as specific OEM
version.
Müller Industrie-Elektronik GmbH
www.mueller-ie.com
98 heat processing 1-2014

www.heatprocessing-online.com
Order now!
Open board digital
temperature controllers
The 5R7-570(A) RoHS compliant open board electronic
temperature controllers are specifically de-signed
with a proportional integral control algorithm to provide
the most precise control to thermoelectric modules
(Peltier) at the most economical price. The H-bridge
temperature control provides a seamless transition
between heating and cooling eliminating dead spots.
Green LED for heat and blue LED for cooling indicate
mode and simultaneous illumination indicates the load
The international magazine
for industrial furnaces,
heat treatment plants
and equipment
The technical journal for the entire field of industrial furnace
and heat treatment engineering, thermal plants,
systems and processes. The publication delivers comprehensive
information, in full technical detail, on developments
and solutions in thermal process engineering for
industrial applications.
Make up your mind on how to subscribe!
· The printed volume suits the classic way of reading.
· The e-paper issue offers the modern way of receiving
informationon a computer, tablet pc or smart phone.
· The printed volume + e-paper issue combine the best
of both worlds.
circuit is off due to an open sensor. Pulse width modulation
controls the power level in the thermoelectric
module at a base frequency of 1 Khz. Power resolution
is one of ±250 steps in the load circuit control. This
small package temperature controller 1.75” x 3.5” X 3”
with input voltage: 6 to 28 VDC, Output Voltage: 0 to
36 VDC, Load Current 0.1 to 12.5 Amps, 450 W output
power control, control stability: ± 0.1 °C and temperature
range of -20 to 150 °C.
Oven Industries, Inc.
www.ovenind.com
heatprocessing
Stay informed and follow us on Twitter
heat processing
@heatprocessing
heat processing is the international magazine for industrial furnaces,
heat treatment & equipment
Essen · http://www.heatprocessing-online.com
heat processing is published by Vulkan-Verlag GmbH, Huyssenallee 52-56, 45128 Essen, Germany
1-2014 heat processing
KNOWLEDGE FOR THE
FUTURE

PRODUCTS & SERVICES
Compact temperature sensors
With OPTITEMP TRA-C10, TRA-C20 and
TRA-C30, Krohne introduces its new
line of compact temperature sensors. They
follow the current trend in various industries
where in standard applications traditional
temperature sensors are replaced with compact
ones, especially in OEM applications.
Unlike traditional sensors that have to be
configured by choosing from various combinations
of measuring
insert, thermowell
and transmitter,
the compact sensors
are pre-configured
with an integrated
transmitter to meet
the most common
requirements in terms
of measuring range,
immersion length as
well as process- and
electrical connections.
Their main
advantage is their
size: as in many process
and OEM applications
there is only
limited space for sensors,
they feature a small housing design.
Although they aim at different fields of
application, OPTITEMP TRA-C10, TRA-C20
and TRA-C30 share the same basic design:
equipped with Pt100 class A sensor element
and build-in analogue transmitter,
they cover the temperature range from
-50…+150 °C/58…302 °F (without integrated
transmitter +200 °C/392 °F) for
liquid and gaseous mediums. Accuracy is
±0.15 % of measuring range. For immediate
use, the measuring range is fixed and
pre-configured to a 4…20 mA output, no
programming is needed.
All three compact sensors come in standard
immersion lengths 50 or 100 mm/2 or
4” (on request 25…500 mm/1…20”). Also,
the short transmitter response time of the
compact sensors (for water t 0.5 = 3.2 s, t 0.9
= 9.0 s) indicates changing process conditions
very quickly and allows for immediate
reaction. Classed IP67/65, the sensors are
dust tight and can be used in wet outdoor
environments. The solid mechanical design
has no moving parts, which makes the sensors
highly resistant to mechanical stress or
adverse environmental conditions.
All standard versions of the three sensors
have a fixed part number for a smooth
buying process. Next to being available
through Krohne sales, they will be placed
in online shops to be bought right off-theshelf.
Non-standard combinations are also
available on request.
Krohne Messtechnik GmbH
www.krohne.com
Mobile metal analyzer features metal database
Spectro Analytical Instruments now
offers direct access to its Spectro Metal
Database on the latest versions of its Spectrotest
mobile metal analyzer. Users will not
only save time conducting metal assessments
but will no longer need to purchase
various catalogs of metal standards. Stored
in the metal database are specifications for
more than 150,000 metal alloys according
to international standards for steels and
non-ferrous metals.
The Metal Database serves as a universal
tool for providing detailed information
about metal alloys and their mechanical
properties. Among its strengths is the ability
to search for suitable alloys, to identify
unknown materials based on the chemical
content, and to export material specifications
for use on a particular spectrometer.
The software supports users working with
the Spectro iSORT, xSORT, Spectrotest
(additional direct access), Spectromaxx and
Spectrolab. All new Spectrotest (TXC03)
analyzers have a test version of the Spectro
Metal Database pre-installed.
With the new metal database, the
analysis has been made even easier. With
unknown alloys, it is possible for users to
search for materials. Pressing a key starts
the extended material search from the
measuring screen. It is then possible to
determine within which material specifications
the analysis fits. By importing materials
from the list of results, the alloys can be
quickly and simply entered into the library
on the Spectrotest.
Spectro Analytical Instruments GmbH
www.spectro.com
100 heat processing 1-2014

PRODUCTS & SERVICES
Dosing furnace with new control system
In January StrikoWestofen Group presented
its redesigned Westomat dosing furnace
with the new “ProDos 3” control system. The
new system will replace the current “ProDos
XP” control in the first quarter of 2014 and
will offer additional dosing precision and
process reliability. Considerably improved
computing power reduces the reaction time
by a factor of three, thus adjusting the dosing
weight to altered process parameters in
a highly efficient way. The most important
innovation is probably the integration of
the patented biscuit correction. This has
proved to be an effective practical tool for
improving the dosing accuracy by another
35 %. Its direct integration into the control
means that biscuit correction as well as the
standardized DISPO 035 interface to the
die-casting machine are now available to
all customers as economical options. Electrically
and mechanically, the ProDos 3 is
completely compatible with
the current ProDos XP and
DPC control units.
The new control system
is especially resistant to
electromechanical disturbances
and is operated via
a capacitive touchscreen.
This no longer needs to
be calibrated and is effectively
protected in everyday
foundry operation via a pane
of toughened glass.
The often ext remely
restricted space in foundries
and around the die-casting
machine is taken into account by a new
furnace body. A completely revised design
allows to reduce the space requirements by
about 15 % in comparison with the predecessor
model. The slim dimensions allow
the dosing furnace to be positioned closer
to the die-casting machine.
StrikoWestofen Group
www.strikowestofen.com
Handbook of Refractory Materials
Design | Properties | Testings
This new edition of the Handbook of Refractory Materials has been completely
revised, expanded and appears in a compact format.
Readers obtain an extensive and detailed overview focusing on design,
properties, calculations, terminology and testing of refractory materials
thus providing important information for your daily work. The appendix
was supplemented by following suggestions of readers. Consequently, the
handbook‘s usability was enhanced even further. With the great amount of
information this compact book is a necessity for professional working in the
refractory material or thermal process sectors. The e-book offers even more
flexibility while travelling.
Editors: G. Routschka / H. Wuthnow
4 th edition 2012, 344 pages, with additional information and e-book on DVD, hardcover,
ISBN: 978-3-8027-3162-4
€ 100,00
Order now:
Tel.: +49 201 82002-14
Fax: +49 201 82002-34
bestellung@vulkan-verlag.de
Order now!
KNOWLEDGE FOR THE
FUTURE
1-2014 heat processing
101

INDEX OF ADVERTISERS
INDEX OF ADVERTISERS
Company Page Company Page
57 th International Colloquium on Refractories 2014,
Aachen, Germany 25
AFC-HOLCROFT, Wixom, Michigan, USA 9
ALD Vacuum Technologies GmbH, Hanau, Germany 57
ALUMINIUM 2014, Düsseldorf, Germany 27
ALUMINIUM BRAZIL 2014, Sao Paulo, Brazil 78
ANKIROS/ANNOFER/TURKCAST 2014, Istanbul, Turkey 28
Bürkert GmbH & Co. KG, Ingelfingen, Germany 17
Elster GmbH, Osnabrück, Germany 5
FABTECH Canada 2014, Toronto, Canada 72
JASPER Gesellschaft für Energiewirtschaft und Kybernetik mbH,
Geseke, Germany 13
LOESCHE Thermoprozess GmbH, Düsseldorf, Germany 11
Metal + Metallurgy China 2014, Beijing, China 21
Metallurgy Litmash 2014, Moscow, Russia 46
METAV 2014, Düsseldorf, Germany 31
PlaTeG GmbH, Wettenberg, Germany 45
SECO/WARWICK Service GmbH,
Bedburg-Hau, Germany
inside front cover, back cover
SMS Elotherm GmbH, Remscheid, Germany front cover, 19
SOLO SWISS Group, Bienne, Schweiz 15
wire 2014 / Tube 2014, Düsseldorf, Germany 22
Business Directory 103 - 123
International Magazine for Industrial Furnaces,
Heat Treatment & Equipment
www.heatprocessing-online.com
your contact to the
heat processing team
Managing Editor:
Dipl.-Ing. Stephan Schalm
Phone: +49 201 82002 12
Fax: +49 201 82002 40
E-Mail: s.schalm@vulkan-verlag.de
Editorial Office:
Annamaria Frömgen
Phone: +49 201 82002 91
Fax: +49 201 82002 40
E-Mail: a.froemgen@vulkan-verlag.de
Advertising Sales:
Bettina Schwarzer-Hahn
Phone: +49 201 82002 24
Fax: +49 201 82002 40
E-Mail: b.schwarzer-hahn@vulkan-verlag.de
Advertising Administration:
Martina Mittermayer
Phone: +49 89 203 5366 16
Fax: +49 89 203 5366 66
E-Mail: mittermayer@di-verlag.de
Editor:
Thomas Schneidewind
Phone: +49 201 82002 36
Fax: +49 201 82002 40
E-Mail: t.schneidewind@vulkan-verlag.de
Editor (Trainee):
Sabrina Finke
Phone: +49 201 82002 15
Fax: +49 201 82002 40
E-Mail: s.finke@vulkan-verlag.de
102 heat processing 4-2013 1-2014
www.heatprocessing-online.com

International Magazine for Industrial Furnaces
Heat Treatment & Equipment
www.heatprocessing-online.com
2014
Business Directory
I. Furnaces and plants for industrial
heat treatment processes ......................................................................................... 104
II.
Components, equipment, production
and auxiliary materials ................................................................................................ 114
III. Consulting, design, service
and engineering ............................................................................................................ 122
IV. Trade associations, institutes,
universities, organisations ......................................................................................... 123
V. Exhibition organizers,
training and education .............................................................................................. 123
Contact:
Mrs. Bettina Schwarzer-Hahn
Tel.: +49 (0)201 / 82002-24
Fax: +49 (0)201 / 82002-40
E-mail: b.schwarzer-hahn@vulkan-verlag.de
4-2013 heat processing
www.heatprocessing-directory.com
103

Business Directory 1-2014
I. Furnaces and plants for industrial heat treatment processes
thermal production
Melting, Pouring, casting
104 heat processing 1-2014 4-2013

1-2014 Business Directory
I. Furnaces and plants for industrial heat treatment processes
Heating
Powder metallurgy
4-2013 1-2014 heat processing
105

Business Directory 1-2014
I. Furnaces and plants for industrial heat treatment processes
Heating
106 heat processing 1-2014 4-2013

1-2014 Business Directory
I. Furnaces and plants for industrial heat treatment processes
Heat treatment
More information available:
www.heatprocessing-directory.com
4-2013 1-2014 heat processing
107

Business Directory 1-2014
I. Furnaces and plants for industrial heat treatment processes
Heat treatment
Your contact to
HEAT PROCESSING
Bettina Schwarzer-Hahn
Tel. +49(0)201-82002-24
Fax +49(0)201-82002-40
b.schwarzer-hahn@vulkan-verlag.de
108 heat processing 1-2014 4-2013

1-2014 Business Directory
I. Furnaces and plants for industrial heat treatment processes
More information available:
www.heatprocessing-directory.com
4-2013 1-2014 heat processing
109

Business Directory 1-2014
I. Furnaces and plants for industrial heat treatment processes
Heat treatment
cooling and Quenching
110 heat processing 1-2014 4-2013

1-2014 Business Directory
I. Furnaces and plants for industrial heat treatment processes
surface treatment
Joining
More information available:
www.heatprocessing-directory.com
4-2013 1-2014 heat processing
111

Business Directory 1-2014
I. Furnaces and plants for industrial heat treatment processes
Joining
recycling
112 heat processing 1-2014 4-2013

1-2014 Business Directory
I. Furnaces and plants for industrial heat treatment processes
energy efficiency
retrofit
Your contact to
HEAT PROCESSING
Bettina Schwarzer-Hahn
Tel. +49(0)201-82002-24
Fax +49(0)201-82002-40
b.schwarzer-hahn@vulkan-verlag.de
4-2013 1-2014 heat processing
113

Business Directory 1-2014
II. Components, equipment, production and auxiliary materials
Quenching equipment
Fittings
Burners
transport equipment
Your contact to
HEAT PROCESSING
Bettina Schwarzer-Hahn
Tel. +49(0)201-82002-24
Fax +49(0)201-82002-40
b.schwarzer-hahn@vulkan-verlag.de
114 heat processing 1-2014 4-2013

1-2014 Business Directory
II. Components, equipment, production and auxiliary materials
Your contact to
HEAT PROCESSING
Bettina Schwarzer-Hahn
Tel. +49(0)201-82002-24
Fax +49(0)201-82002-40
b.schwarzer-hahn@vulkan-verlag.de
4-2013 1-2014 heat processing
115

Business Directory 1-2014
II. Components, equipment, production and auxiliary materials
Burners
Burner equipment
Burner applications
Your contact to
HEAT PROCESSING
Bettina Schwarzer-Hahn
Tel. +49(0)201-82002-24
Fax +49(0)201-82002-40
b.schwarzer-hahn@vulkan-verlag.de
116 heat processing 1-2014 4-2013

1-2014 Business Directory
II. Components, equipment, production and auxiliary materials
Hardening accessories
More information available:
www.heatprocessing-directory.com
4-2013 1-2014 heat processing
117

Business Directory 1-2014
II. Components, equipment, production and auxiliary materials
resistance heating
elements
Forging accessories
inductors
118 heat processing 1-2014 4-2013

1-2014 Business Directory
II. Components, equipment, production and auxiliary materials
Measuring and automation
Gases
Your contact to
HEAT PROCESSING
Bettina Schwarzer-Hahn
Tel. +49(0)201-82002-24
Fax +49(0)201-82002-40
b.schwarzer-hahn@vulkan-verlag.de
4-2013 1-2014 heat processing
More information available:
www.heatprocessing-directory.com
119

Business Directory 1-2014
II. Components, equipment, production and auxiliary materials
Measuring and automation
Power supply
120 heat processing 1-2014 4-2013

1-2014 Business Directory
II. Components, equipment, production and auxiliary materials
refractories
HOTLINE Meet the team
Managing Editor: Dipl.-Ing. Stephan Schalm +49(0)201/82002-12 s.schalm@vulkan-verlag.de
Editorial Office: Annamaria Frömgen +49(0)201/82002-91 a.froemgen@vulkan-verlag.de
Editor: Thomas Schneidewind +49(0)201/82002-36 t.schneidewind@vulkan-verlag.de
Editor (Trainee): Sabrina Finke +49(0)201/82002-15 s.finke@vulkan-verlag.de
Advertising Sales: Bettina Schwarzer-Hahn +49(0)201/82002-24 b.schwarzer-hahn@vulkan-verlag.de
Subscription: Martina Grimm +49(0)931/41704-13 mgrimm@datam-services.de
4-2013 1-2014 heat processing
121

Business Directory 1-2014
III. Consulting, design, service and engineering
122 heat processing 1-2014 4-2013

1-2014 Business Directory
IV. Trade associations, institutes, universities, organisations
V. Exhibition organizers, training and education
4-2013 1-2014 heat processing
123

COMPANIES PROFILE
Promat HPI
Promat HPI
Contact:
Michael Moreau
Tel.: +32 (0)3 780 / 5396
m.moreau@promat-international.com
COMPANY:
Promat International nv
Bormstraat 24
2830 Tisselt
Belgium
BOARD OF MANAGEMENT:
Steven Heytens, Business Unit Director Promat High Performance
Insulation; Paul Van Oyen, Head of Division Fire Protection and
Insulation at Etex Group
HISTORY:
1958: Foundation PROgressive MATerials
1966: 1 st contacts with Eternit, Belgium
1970’s: Geo-expansion BE, NL, AT, UK, FR, CH
1980’s: Geo-expansion IT, ES, USA, Middle East
1990’s: Geo-expansion Hong-Kong, Singapore, Poland, Czech
Republic, Malaysia, China
1996: Acquisition Comais Italy
1998: Acquisition Fyreguard Australia
2000: Acquisition Intumex Austria
2002: Acquisition Cape Calsil UK
2004: Acquisition Promat Ibérica Spain
2006: Acquisition Projiso France
2007: Acquisition Cafco Int. Luxemburg
2010: Acquisition Microtherm Group
2011: Setup Promat HPI –
Geo-expansion in US and Japan
GROUP:
Promat is a dynamic part of Etex, a Belgian industrial group.
NUMBER OF STAFF:
1,300
PRODUCT RANGE:
Calcium silicate products: lightweight and structural insulation and
advanced technical ceramics; microporous products; fibre matrix
products (E glass, RCF, AES, silica and alumina); refractory products
(monolithics) & lightweight insulating bricks.
COMPETITIVE ADVANTAGES:
The company offers an optimized approach which integrates microporous
insulation with the other insulation products available from
the full Promat range. The portfolio is through ongoing product
developments constantly being updated and improved.
CERTIFICATION:
All products in Belgium, UK and Italy are manufactured under ISO 9001,
ISO 14001, OHSAS 18001. Other production facilities apply the same manufacturing
standards, to ensure the highest quality products and solutions.
SERVICE POTENTIALS:
Worldwide (presence in 38 countries around the globe).
INTERNET ADDRESS:
www.promat-hpi.com
124 heat processing 1-2014

1-2014 IMPRINT
www.heatprocessing-online.com
Volume 12 · Issue 1 · February 2014
Official Publication
Editors
Advisory Board
Publishing House
Managing Editor
Editorial Office
CECOF – European Committee of Industrial Furnace and Heating Equipment Associations
H. Berger, AICHELIN Ges.m.b.H., Mödling, Prof. Dr.-Ing. A. von Starck, Appointed Professor for Electric Heating at RWTH
Aachen, Dr. H. Stumpp, Chairman of the Association for Thermal Process Technology within VDMA, CTO Tenova Iron &
Steel Group
Dr. H. Altena, Aichelin Ges.m.b.H., Prof. Dr.-Ing. E. Baake, Institute for Electrothermal Processes, Leibniz University of
Hanover, Dr.-Ing. F. Beneke, VDMA, Prof. Y. Blinov, St. Petersburg State Electrotechnical University “Leti“, Russia, René
Branders, President of CECOF, Mike Debier, CECOF, Dr.-Ing. F. Kühn, LOI Thermprocess GmbH, Dipl.-Ing. W. Liere-Netheler,
Elster GmbH, H. Lochner, EBNER Industrieofenbau GmbH, Prof. S. Lupi, University of Padova, Dept. of Electrical Eng., Italy,
Prof. Dr.-Ing. H. Pfeifer, RWTH Aachen, Dipl.-Phys. M. Rink, Ipsen International GmbH, Dipl.-Ing. St. Schalm, Vulkan-Verlag
GmbH, M.Sc. S. Segerberg, Heattec Värmebehandling AB, Sweden, Dr.-Ing. A. Seitzer, SMS Elotherm GmbH, Dr.-Ing. P. Wendt,
LOI Thermprocess GmbH, Dr.-Ing. J. G. Wünning, WS Wärmeprozesstechnik GmbH, Dr.-Ing. T. Würz, CECOF
Vulkan-Verlag GmbH, Huyssenallee 52-56, 45128 Essen, Germany
P.O. Box 103962, 45039 Essen
Managing Directors: Carsten Augsburger, Jürgen Franke
Dipl.-Ing. Stephan Schalm, Vulkan-Verlag GmbH
Tel. + 49 201 820 02-12, Fax: + 49 201 820 02-40
E-Mail: s.schalm@vulkan-verlag.de
Annamaria Frömgen, Vulkan-Verlag GmbH
Tel. + 49 201 820 02-91, Fax: + 49 201 820 02-40
E-Mail: a.froemgen@vulkan-verlag.de
Editorial Department Thomas Schneidewind, Vulkan-Verlag GmbH Sabrina Finke (Trainee), Vulkan-Verlag GmbH
Tel. + 49 201 820 02-36, Fax: + 49 201 820 02-40 Tel. + 49 201 820 02-15, Fax: + 49 201 820 02-40
E-Mail: t.schneidewind@vulkan-verlag.de
E-Mail: s.finke@vulkan-verlag.de
Advertising Sales
Bettina Schwarzer-Hahn, Vulkan-Verlag GmbH
Tel. + 49 201 820 02-24, Fax: + 49 201 820 02-40
E-Mail: b.schwarzer-hahn@vulkan-verlag.de
Advertising
Martina Mittermayer, Vulkan-Verlag GmbH / DIV Deutscher Industrieverlag GmbH
Administration Tel. + 49 89 203 53 66-16, Fax: + 49 89 203 53 66-66
E-Mail: mittermayer@di-verlag.de
Layout
Terms of subscription:
Daniel Klunkert, Vulkan-Verlag GmbH
heat processing is published four times a year.
Rates: Subscription: € 170,- + € 14,- shipping
Single copy: € 49,- + € 3,50 shipping
Subscription with access to online archive: € 235,-
Subscription ePaper: € 170,-
Subscription ePaper & acces to online archive: € 221,-
Abo plus Print & ePaper: € 235,-
Abo plus Print & ePaper & acces to online archive: € 286,-
Students: 50% reduction on normal subscription rate (proof of entitlement)
Orders may be placed at any time. Please address directly to our customer service or your local book shop. Subscriptions
continue for another year unless terminated in writing 2 months prior to the end of each year.
Subscriptions/
Leserservice heat processing . Postfach 91 61 . 97091 Würzburg
Single Copy Sales Tel. +49 931 4170-1616, Fax: +49 931 4170-492
E-Mail: leserservice@vulkan-verlag.de
Printed by
The magazine and all the contributions and illustrations contained therein are secured by copyright. With the exception
of the legally permitted instances, any utilisation without the express permission of the publisher will be punished at law.
The opinions contained in signed articles do not necessarily reflect the opinion of the publisher.
Druckerei Chmielorz GmbH
Ostring 13 · 65205 Wiesbaden-Nordenstadt
© 2003 Vulkan-Verlag GmbH
Huyssenallee 52-56 · 45128 Essen (Germany)
Tel. + 49 201 820 02-0, Fax + 49 201 820 02-40
ISSN 1611-616X
Mitglied der Informationsgemeinschaft zur
Feststellung der Verbreitung von Werbeträgern e.V. (IVW)