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HIGH GRADE STEEL & PRECISION CASTING
TECHNICAl BUllETIN NO. 4
C a s t i n g E n g i n E E r i n g
i n n o vat i o n
Tailor Made Casting Designs
Wolfensberger Casting Engineering optimises design ideas with focus on the result.
Planned castings are adapted to customers’ requirements and designed for casting, allowing for all the
essential variables - material requirements, castability, machinability and cost optimisation.
It all starts with an idea by designers and developers. Our engineering department combines requi-
rements for component and material characteristics and optimum machinability into a casting design
ready for manufacture, destined for serial production. Our years of experience in the design of castings
and our profound metallurgical knowledge cut the lead time for new casting projects to a minimum.
Reducing the design of castings to its essentials
Wolfensberger Casting Engineering
Six Steps to Engineering Excellence
A well thought-out process, from A to Z:
The Wolfensberger engineering team integrates the customer’s speci-
fications, i.e. all the external factors, into casting design in six stages,
professionally and single-mindedly: 1 Feasibility study
2 Casting design 3 Material selection
4 Computer simulation of solidification 5 Production of prototypes
6 Release for serial production
Your partner for material
development
Wolfensberger undertakes sound
material development in the field of cast
steel alloys for specific applications for
distinguished clients such as Daimler AG
in Germany and ABB Turbo Systems AG in
Switzerland.
The Wolfensberger metallurgy team
develops alloys on the basis of customer
specifications, optimised for the specific
application, from basic research to serial
production level.
Our metallurgists also guarantee the
perfect material quality of alloys which
have been cast in serial production for
years, such as austenitic nodular cast iron
(Ni-Resist), wear resistant cast iron, corro-
sion resistant stainless steel, creep- and
heat-resistant steel and high-temperature-
resistant nickel- and cobalt-based alloys.
The corrosion resistance of high-chromium wear resistant alloys can be adjusted to customer requirements across a wide range by fine adjust-ment of its chemical composition.
Casting Design Consulting
Unequalled by other manufacturing processes,
casting gives designers and engineers a broad
spectrum for the design and implementation of
ideas in the development of complex mecha-
nical engineering components.
We recommend bringing in the expertise of
casting specialists from the initial stages of
planning, in order to make full use of the almost
unlimited freedom of functional design of metal
components.
Reaching Your Goal more Quickly and
Economically
It is a fact that design geometry has approxi-
mately 80% influence on component characte-
ristics, with material properties accounting for
the other 20%. This means, for example, that
intelligent, professional input by casting specia-
lists can considerably improve the mechanical
strength of a newly-designed casting and
simultaneously minimise the error (reject) rate
whilst using the same material. This obviously
has a positive effect on production costs.
Integration of all Variables
As a first step, Wolfensberger’s casting specia-
lists use their years of experience in Exacast®
precision ceramic casting and sand casting to
optimise a potential casting design in terms of:
Favourable cross-section and weight
distribution
Avoidance of material clustering
Placement of reinforcements
(optimised for casting)
Specific selection of materials
Optimisation of machining allowances
Placement of machining aids (cams, lugs, etc.)
Heat treatment consists of heating
metal components, particularly in steel
and cast iron, to a defined temperature
for a defined period, using heating and
cooling gradients, in order to enhance
the properties of the material.
Heat treatment gives components the
properties such as hardness, toughness
and tensile strength required for their
subsequent specific use.
The factors time (heating up and holding
time), temperature, atmosphere and
quenching or cooling are crucially im-
portant.
The Effects of Heat Treatment
Wolfensberger perform heat treatment in-house or in close cooperation with well-established external heat treatment contractors.
Alignment with customer requirements: years of tradition combined with state
of the art casting technology enable Wolfensberger to implement engineers’
specifications, from a virtual concept to an actual casting.
The Wolfensberger range of engineering services
Cost savings: casting design optimised for machining
Computer-Assisted Simulation of Solidification
The undisputed advantage of using
solidification simulation is the time-
saving factor. Time-consuming one-
to-one experiments at the foundry can
largely be eliminated and the production
time for prototypes can be reduced to a
minimum. On the cost side, the use of
solidification simulation for testing new
castings provides attractive advantages.
If the pattern set is designed in accor-
dance with the optimised results of soli-
dification simulation, there is a very high
probability that no complicated modifica-
tions of the pattern set will be necessary
following prototype casting. The success
rate for initial samples and prototypes is
also exponentially higher than with the
traditional trial and error method, which
in turn leads to lower costs.
The filling process
Objective: rapid, steady filling,
free of turbulence
Transition from the filling to the
solidification process
Objective: homogeneous temperature distribu-
tion (a prerequisite for the quality of castings)
Solidification process
Objective: oriented solidification
(a prerequisite for freedom of pores)
The Filling and Solidification Process in Three Stages
Professional simulation of solidification is
replacing traditional casting development,
based upon experience gained empirically
and cost-intensive test castings.
Wolfensberger casting engineering has been
using virtual trials of component designs and
layouts suitable for casting successfully for
years. The significance of solidification simula-
tion has been corroborated by validation tests.
All newly designed parts are subject to solidifi-
cation simulation at Wolfensberger to ensure a
smooth transition to serial production.
Computer-assisted simulation tools have been
providing a wide range of possibilities for
reducing development time and eliminating
sources of error in casting design for a number
of years.
Customer Benefits
Stage 1 Stage 2 Stage 3
Exacast® ceramic precision casting in hot moulds.
Complex Technology for Detecting
Weaknesses and Faults
The use of digital simulation of casting proces-
ses in the development of castings includes the
following operations:
Optimisation of mould filling with the
selected alloy
Determination of filling and solidification time
Simulation of the solidification process
Display of probable defects during solidification
Determination of thermal stress in terms of potential warping or susceptibility to cracking
Wolfensberger can consider specific customer
requirements, thanks to its experienced
team of metallurgists and modern materials
laboratory.
Starting at the development stage, our spe-
cialists work with your designers to prepare
proposals for tailor made alloys which meet
your specific needs.
Stainless Steel Alloys
Wolfensberger casts all the major stain-
less steel alloys: corrosion-, rust- and
acid-resistant, highly creep-resistant and
wear-resistant.
Highly alloyed cast steel allows the cost-
effective combination of multiple properties
in one material, e.g. excellent resistance to
corrosion, high tensile strength and notched
bar impact strength.
Highly-alloyed steel is particularly suitable for
highly-stressed machine parts in the energy
industry, pump construction, transmission
systems, the automobile industry, etc.
Austenitic Cast Iron
Austenitic cast iron alloys with nodular
graphite (Ni-Resist) have particular techno-
logical and physical properties that make
them suitable for many uses under extreme
conditions. They are principally distinguished
by the following properties: resistance to
corrosion, scaling and thermal shock, high
ductility, resistance to erosion, favourable
operating characteristics, low-temperature
toughness and non-magnetisability.
Wear resistant cast iron alloys
Extensive Material Skills
Creep resistance of high-temperature material groups
Temp. °C
500
400
300
200
400 600 800 1000 1200
100
0
Ti alloys Ni-based alloys
Co-based alloys
Austenitic steels
Relationship between corrosion resistance and strength of stainless steels
Austenitic steels
Ferritic steels
Superferritic steels
Ferritic-austenitic steels
Nickel-martensitic steels
Martensitic steels
Corrosion resistance
Strength
Wear resistant cast iron alloys
Wear resistant cast iron alloys (high chro-
mium alloys and Ni Hard) are also known as
chromium-molybdenum white iron. They are
used when abrasion by non-metallic materials
occurs.
They contain a high proportion of iron and
chromium carbides, which act as hardening
materials, embedded in the metallic matrix.
Such materials display medium to high
resistance to corrosive attacks, depending
upon their chromium content.
Nickel-based alloys
Nickel-based alloys have superior resistance
to corrosion and high temperature and may
possess special physical properties such
as electrical resistance, controlled thermal
expansion, particular magnetic properties, etc.
Our metallurgists guarantee the perfect
material quality of alloys which have been
used for series casting for years, such as
austenitic nodular cast iron (Ni-Resist), wear
resistant cast iron, corrosion resistant stainless
steel, creep- and heat-resistant steel and
high-temperature resistant nickel- and cobalt-
based alloys.
Thanks to the wide range of materials, the
right steel or cast iron alloy can be found for
almost any application.
HubCorrosion-resistant DUPlEX material
RotorDuctile cast iron or corrosion-resistant cast steel
Nozzle ringHeat-resistant cast steel or nickel-based alloys
Bainitic-martensitic steels
Refractory alloys
Rm 104h, MPa
Your Partner for Convincing Casting Solutions.
Wolfensberger:
Innovation rooted in tradition
Established in 1924
– A family-owned corporation
– Two plants in Bauma (foundry and chipping),
employing about 250 people
– About 1,500 tonnes of cast steel and iron
materials annually
– Satisfied customers: ABB Turbo Systems
AG, MAN Diesel & Turbo, Voith Turbo GmbH,
Alstom Schweiz AG, Bühler AG, Andritz AG,
etc.
– Proven specialist skills and high quality
Sand casting
– Small to medium production runs
– Manual or machine moulding with furan
resin-bonded sand
– Wide range of iron and steel casting materials
– Weight range: 10kg to 2000kg
Advice from casting professionals
Wolfensberger casting and engineering
advocates active cooperation with the client
from the outset and will support you in design
(optimising the casting) and in the selection of
the correct material (optimisation in terms of
wear, resistance to corrosion, better machina-
bility and castability, etc.).
Exacast® ceramic precision casting
– Suitable for parts with high demands on
tolerances, surface quality and thin-walled
sections
– Small to medium production runs with high
weights in lost-wax casting quality
– Wide range of iron and steel casting materials
– Weight range: 2 kg to 400 kg
Wide range of materials
– Broad range of experience in metallurgy,
casting techniques and the selection of
material
– State-of-the-art laboratory
– Range of materials including about 100 iron
and steel casting materials
In-house machining
– We supply castings with prove machining or
ready-machined for installation
– CNC machines for handling axially symmet-
rical and cubic parts
– In-house face and profile grinding shop
– Subcontracted finishing of parts or semi-
finished productsIn-house machining.
Our quality depends upon the commitment of each and every employee.
Wolfensberger’s headquarters.In Bauma, near Zürich, since 1924.
Your logistics partner
We will take care of all your logistics and/or the
fitting of subassemblies.
Continuous optimisation:
Quality assurance
Wolfensberger uses a management system
certified under ISO 9001:2008.
The constantly updated tools include:
– A computer-assisted planning and control
system
– A metallurgical laboratory
– Non-destructive testing (PT, MT, UT and RT)
Plant 2 with chipping and refinishing shop for castings.
Microstructural tests are carried out in our metallur-gical laboratory.
Wolfensberger AG
Bäretswilerstrasse 45, CH-8494 Bauma
T +41 52 396 11 11, F +41 52 396 15 50
www.wolfensberger.ch, [email protected] GRADE STEEL & PRECISION CASTING