Hot Runners and Mould Components - ETMM-Online

36
Case Studies
Forging Company Makes Dies
from Tough, Hard Tool Steel
Toolox 44 possesses properties that enable the manufacturer to produce highquality
prototypes and small series of die-forged parts quickly.
Krenhof AG of Köflach,
Austria, produces about
10 million die-forged parts
annually. Its customers are
primarily in the automotive
industry but also include
manufacturers of commercial
vehicles, chain producers, and
companies in the formwork
technology and mechanical
engineering industries. The
company is operating in its
métier especially when it produces
complex parts in the
medium-series range, but it
can offer quality and logistics
capabilities befitting a highervolume
production level.
Importantly, Krenhof has
been able to compete and
grow thanks to continuous
investment and the introduction
of innovations along the
entire process chain. Noteworthy
is the fact that the
company recently began to
use Toolox 44 tool steel from
SSAB for its forging dies.
With its special properties,
Toolox 44, which has a hardness
of approximately 45 HRc/450 HB,
assumes a special position. This
steel offers an optimal compromise
between hardness and
toughness. It provides good temperature
toughness against the
formation of fire cracks while at
the same time being resistant to
abrasion. Toolox 44 is quite amenable
to all standard separation
and prestressing processes.
SSAB gives the steel its high
purity and outstanding toughness
by formulating it with a low
Krenhof can quickly and flexibly produce die-forged
components in series of 1,000 to 10,000 parts. This
capability is supported by Toolox 44 tool steel, which has
proven itself with demanding moulding tool geometries.
carbon content. As an additional
benefit, it delivers Toolox already
hardened and tempered, which
saves the customer additional processing
expenditure.
“We use Toolox 44 tool steel
for prototypes and small series,”
says Matthias Hartmann, Krenhof’s
managing director. “Formation
of fire cracks is worst at the
beginning of the forging, while
abrasion is nowhere near as common
here. This allows us to refrain
from using shielding, without the
customer experiencing any disadvantages
in terms of surface quality
or dimensional stability.”
Today’s customers are
demanding shorter delivery
times for their forged products,
Hartmann remarks.
But that’s no problem. As
Hartmann explains, “Toolox
44 has proven itself with
demanding moulding tool
geometries, as well.” This is
important because “the speed
at which one can produce
prototypes is often decisive
when it comes to being hired
as a series supplier.”
Krenhof AG uses state-ofthe-art
methods in construction
and toolmaking to ensure
an efficient development
process. During the essential
production steps of cutting,
forging and heat treatment,
high-quality machines and
dedicated employees are able
to hold tolerances for dimensions,
shape and joints very
close; for users, this means
that their own processes will
run better. Rigorous production
planning and the on-line collection
of operational data help to
ensure that agreed-upon schedules
are met. And, with Toolox
44 tool steel in its arsenal of
advanced technologies, Krenhof
can produce small and pilot production
series of forgings quickly.
No one is surprised that the
company has grown by an average
of better than 10% per year
for the past 15 years.
» SSAB Oxelösund AB
Oxelösund, Sweden
www.ssabox.com
European Tool & Mould Making | May 2011 | www.etmm-online.com