NIROSTA® 4565 S (UNS S 34565) - ThyssenKrupp Nirosta

A company
of ThyssenKrupp
Stainless
NIROSTA ® 4565 S (UNS S 34565)
Nitrogen-alloyed austenitic stainless steel
with maximum corrosion resistance
and high strength
ThyssenKrupp Nirosta
ThyssenKrupp

NIROSTA ® 4565 S
Properties and applications
NIROSTA ® 4565 S (UNS-number
S 34565) is a high-nitrogen, fully
austenitic stainless steel which features
both high strength and excellent corrosion
resistance in a wide range of
corrosive media.
It was originally developed for
applications in high-chloride environments,
especially seawater. The highnitrogen
content ensures stable austenitic
structure, high strength and outstanding
pitting and crevice corrosion
resistance in the as-quenched
and even in the as-welded condition.
NIROSTA ® 4565 S is recommended
for use especially in equipment
for the chemical and pulp & paper
industries as well as for the transport
and storage of bulk chemicals. Because
of its outstanding corrosion
resistance, it is very suitable for applications
in flue-gas desulphurization
(FGD) systems, seawater desalination
plants and other environmental technologies.
Its resistance to chlorideinduced
pitting and crevice corrosion
enables it to be used succesfully in
the production and transport of oil
and gas on on-shore and off-shore
facilities.
Fig. 1
NIROSTA ® 4565 S –
effect of isothermal
ageing on notched-bar
absorbed energy
Ageing temperature (°C)
1200
1000
800
Processing and welding
200 J
NIROSTA ® 4565 S can be easily
cold worked.
Compared to unalloyed steels,
the degree of cold work hardening
is much higher, leading to the need
for stronger forces. With NIROSTA ®
4565 S, hardening after cold working
lies in the same range as
with other nitrogen-alloyed austenitic
steels. The increase in the mechanical
characteristics is very nearly linear
up to a degree of cold working of
approx. 40 %.
In general, cold and hot working
and a possible final heat treatment
can be carried out according to the
stipulations of the AD-Worksheet
HP 7/3.
However, since the material
1.4565 S is not actually mentioned
by name in the AD-Worksheet, we
recommend checking with the particular
approval association.
Tempering colours or scale from
heat treatment or welding processes
reduce corrosion resistance and
should therefore be removed chemically
(e.g. by pickling baths or pastes)
or mechanically (e.g. by grinding
or blasting with glass pellets or nonferrous,
sulphur-free quartz sand).
Due to the tendency to cold work
hardening and the poor thermal conductivity,
machining should be carried
out with tools made of high
quality, high-speed steel (effective
cooling essential) or, still better, with
tungsten carbide tools.
NIROSTA ® 4565 S can be mirrorpolished.
100 J
600
0.1 1 10
Ageing time (hrs)
NIROSTA ® 4565 S can be welded
by all conventional procedures
(SMAW, GTAW, GMAW, SAW).
Optimum corrosion resistance is, of
course, obtained using GTAW.
In order to retain the mechanical
and chemical corrosion properties, a
higher-alloyed filler metal must be
used. To date, the best results have
been obtained with the nickel alloy
Thermanit Nimo C. Post-weld heat
treatment is not necessery.
Microstructural stability
100
Nitrogen is a strong austenite
stabilizing alloying element. Beside
its beneficial effects on both strength
and corrosion resistance of NIROSTA ®
4565 S it delays the precipitation
of carbides and intermetallic compounds
on thermal ageing. Fig. 1
shows the time-temperature-sensitization
behaviour of NIROSTA ® 4565 S.
A decrease to the 100 J level is effected
only after ageing 1 hour at 800
°C. Since welding heat is normally
only present for much shorter times,
this result shows that even thicker
work pieces can easily be welded
without the risk of embrittlement.
Similar behaviour was found
when testing the pitting corrosion behaviour
of thermally aged specimens.
This finding, too, confirms the
excellent corrosion resistance of
NIROSTA ® 4565 S in the as-welded
condition.

Product range
Hot-rolled sheet and plate
Thickness Width Length
12–

Fig. 2
Critical pitting and
crevice corrosion
temperatures in 6 %
ferric chloride solution
Critical temperature in (°C)
100
Corrosion Resistance
50
316 L
The primary intention in developing
NIROSTA ® 4565 S was to
provide a material with excellent
resistance to chloride-induced pitting
and crevice corrosion. The chromium
and molybdenum contents and the
high nitrogen content result in a
pitting index of over 50. The pitting
index is calculated according to:
W = % Cr + 3.3 % Mo + 30 % N and
is considered a measure for the resistance
to pitting and crevice corrosion.
Testing NIROSTA ® 4565 S in
ferric chloride solution according to
standard ASTM G 48, an actual
critical pitting temperature (CPT) of
85 °C was determined. Under these
testing conditions the same CPT was
achieved only by the Ni-base alloy
625 corr. N 06625 (Fig. 2).
A similar behaviour was found
testing NIROSTA ® 4565 S in ferric
chloride solution under crevice conditions
according to MTI-standard.
The actual critical crevice temperature
of 55 °C, too, is achieved only by
the Ni-base alloy 625, under the
same condition.
A very important feature of
NIROSTA ® 4565 S is that its excellent
resistance to pitting corrosion is only
slightly lower when tested in the
welded condition.
Fig. 3 shows the CPT’s determined
in ferric chloride solution
according to the ASTM G 48 standard,
of a GTA-welded (no filler) test specimen
(70 °C) and of a specimen
welded with the recommended filler
material Thermanit Nimo C (75 °C)
which are only 15 and 10 °C respectively
lower than that of the unwelded
specimen (85 °C). This assures good
pitting corrosion
crevice corrosion
317 LMN
S 31803
N 06625
1.4529*
N 08904
1.4565 S
0
25 30 35 40 45 50 55
Pitting index PRE = % Cr + 3.3 % Mo + 30 % N
*1.4529 = 20 Cr – 25 Ni – 6 Mo –1Cu – 0.2 N stainless
corrosion resistance of the welded
structures without post-weld heat treatment.
Because of the austenitic structure
which is precipitation free in the
solution annealed and quenched
condition, NIROSTA ® 4565 S also
features an excellent overall corrosion
resistance to a wide range of
aggressive media including oxidizing
and reducing acids even when these
are contaminated with halogenide
impurities.
Fig. 3
Critical pitting
temperature of
NIROSTA ® 4565 S
unwelded and welded,
according to the
ASTM G 48 test
Mass loss rate (g/m 2 h)
Critical pitting temperature (°C)
100
50
0
0,07
0,06
0,05
0,04
0,03
0,02
0,01
Fig. 4 shows the mass loss rates
of NIROSTA ® 4565 S tested in contaminated
super phosphoric acid
compared to other commonly used
materials.
An important advantage of
NIROSTA ® 4565 S is its superior behaviour
in numerous different media,
permitting applications of this highalloy,
high-strength special steel in
plants where complex demands have
to be fulfilled.
unwelded without filler with Nimo C
GTA-welded
Test conditions:
70 % P 2 O 5 + 3 % H 2 SO 4
+ 1% Fe (III) + 0,6 % HF
100 °C, 24 hours
Fig. 4
Mass loss rates
in super
0,00
phosphoric acid S 31803 316 L 317 LMN 1.4565 S

Seawater desalination
Because of a worldwide increase
in population and per capita water
consumption the limited fresh water
resources cannot meet all the requirements
of industry, agriculture and private
households.
Seawater desalination plants have
been built for more than two decades
to cope with the permanent dispro-
Flue-gas desulphurization
A flue-gas desulphurization plant
(FGD) is effectively a chemical plant
incorporated into a power station. Its
purpose is to separate noxious materials,
primarily sulphur, from the flue
gases. Chemical processes occurring
in flue-gas desulphurization plants
are determined by a wide range of
corrosive media with high chloride
contents and low pH-values at operating
temperatures between 50 and
130 °C. Laboratory tests in a simu-
portionately high growth in demand
for drinking water. There is a further
need to increase the desalting capacity
in the coming years.
Materials selected for application
in seawater desalination plants must
be resistant to corrosion over a wide
temperature range. Due to the combination
of excellent corrosion resistance
and high strength NIROSTA ® 4565 S
is ideally suited for the fabrication of
lated flue-gas condensation liquor
show that NIROSTA ® 4565 S exhibits
superior pitting corrosion resistance
compared to steels with 6 % molybdenum
and is comparable with some
nickel-based alloys in this respect
(Fig. 5).
Based on these results, NIROSTA ®
4565 S can be regarded as suitable
for applications in the absorber and
quencher equipment of REA scrubbing
towers.
chamber walls, heat exchanger tubes
and tube sheets of desalination plants.
Depending on the operating
conditions, application temperatures
of more than 100 °C can be handled.
Offshore applications
NIROSTA ® 4565 S, being a nitrogen-alloyed
austenitic stainless steel
with maximum pitting corrosion resistance
and high strength, is suitable
for utilization in systems where complex
demands have to be fulfilled.
Taking into consideration its high
strength, a reduction of the employed
material thickness can be achieved.
NIROSTA ® 4565 S can be applied
e.g. for seawater piping systems,
heat exchangers and high pressure
systems.
Critical pitting temperature (°C)
100
80
60
40
20
0
Test conditions:
synthetic FGD-solution
7 v/% H 2SO 4
3 v/% HCI
1 % FeCI 3
1 % CuCI 2
N 08904
317 LMN
S 31254
N 06625
1.4565 S
Fig. 5 Critical pitting
temperature in a synthetic FGD-solution

ThyssenKrupp Krupp Thyssen Nirosta GmbH
Oberschlesienstr. 16
47807 Krefeld, Germany
Postal address:
47794 Krefeld, Germany
Tel. +49(0)215183-01
Fax +49(0)215183-2022
www.nirosta.de
marketing@ktn.thyssenkrupp.com
Range of products
● Cold-rolled strip
and sheet
● Hot-rolled strip
and sheet
● Four high mill
and checker plate
● Precision strip
in the steel grades
● NIROSTA ®
stainless
● THERMAX ®
heat-resistant
● CRONIDUR ®
high-temperature
● AMANOX ®
non-magnetic
● RADIONOX ®
Cold and hot strip products Four-high mill plate Range of products
Via head office in Krefeld profit-center
● Cold-rolled strip
you can reach:
Sales and Technical product and sheet
Sales Western Europe
– Trading/Steel service centers
– Automotive/Pipes and tubes/
Apparatus construction
– Domestic appliances/
Kitchens/Kegs
– Cold rollers/Hollow-ware/
Civil construction
Logistics-center
service can also be reached
via head office in Krefeld.
Precision strip profit-center
Sales and Technical product
service
Volmestr. 69
58579 Schalksmühle, Germany
P.O. Box 2140
● Hot-rolled strip
and sheet
● Four high mill
and checker plate
● Precision strip
in the steel grades
● NIROSTA
Technical product service
Marketing
58574 Schalksmühle, Germany
Tel. +49(0)235581-0
Fax +49(0)235581-200
radiation-absorbing
®
stainless
● THERMAX ®
heat-resistant
● CRONIDUR ®
high-temperature
● AMANOX ®
non-magnetic
● RADIONOX ®
Cold and hot strip products Four-high mill plate
Via head office in Krefeld profit-center
you can reach:
Sales and Technical product
Sales Western Europe
– Trading/Steel service centers
– Automotive/Pipes and tubes/
Apparatus construction
– Domestic appliances/
Kitchens/Kegs
– Cold rollers/Hollow-ware/
Civil construction
Logistics-center
service can also be reached
via head office in Krefeld.
Precision strip profit-center
Sales and Technical product
service
Volmestr. 69
58579 Schalksmühle, Germany
P.O. Box 2140
Technical product service
Marketing
58574 Schalksmühle, Germany
Tel. +49(0)235581-0
Fax +49(0)235581-200
radiation-absorbing
Sales USA and Canada
ThyssenKrupp Krupp Thyssen Nirosta
North America, Inc.
2275 Half Day Road, Suite 160
Bannockburn, Illinois 60015
Tel. +1 847 317 1400
Fax +1 847 317 1404
Sales other countries
ThyssenKrupp Krupp Thyssen Stainless Nirosta
Export GmbH
Hans-Günther-Sohl-Str. 1
40235 Düsseldorf, Germany
P.O. Box 101046
40001 Düsseldorf, Germany
Tel. +49(0)211967-0
Fax +49(0)211967-5939
DIN EN ISO 9001
Certificate: 04 100 4494
All ThyssenKrupp
Krupp Thyssen
Nirosta’s plants are certified
acc. to ISO 9001.
All statements as to the properties or utilization of the materials and products mentioned in this brochure are for the purpose
of description only. Guarantees in respect of the existence of certain properties or utilization of the material mentioned are only valid
if agreed upon in writing.
Edition 3,
Status 02/2002