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