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, wag@wolfensberger.chHIGH GRADE STEEL & PRECISION CASTING