Tailor Made Casting Designs. Casting. Innovation

Size: px
Start display at page:

Download "Tailor Made Casting Designs. Casting. Innovation"

Transcription

1 HIGH GRADE STEEL & PRECISION CASTING Technical Bulletin No. 4 Casting Engineering Innovation 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.

2 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 A well thought-out process, from A to Z: The Wolfensberger engineering team integrates the customer s specifications, 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 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, 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.

3 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, casting gives designers and engineers a broad spectrum for the design and implementation of ideas in the development of complex mechanical 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 approximately 80% influence on component characteristics, with material properties accounting for the other 20%. This means, for example, that intelligent, professional input by casting specialists 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. Placement of machining aids (cams, lugs, etc.) Cost savings: casting design optimised for machining The Effects of Heat Treatment 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. Wolfensberger perform heat treatment in-house or in close cooperation with well-established external heat treatment contractors. 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 important.

4 Computer-Assisted Simulation of Solidification 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. 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 simulation has been corroborated by validation tests. All newly designed parts are subject to solidification simulation at Wolfensberger to ensure a smooth transition to serial production. Complex Technology for Detecting Weaknesses and Faults The use of digital simulation of casting processes 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 The Filling and Solidification Process in Three Stages Stage 1 Stage 2 Stage 3 The filling process Objective: rapid, steady filling, free of turbulence Transition from the filling to the solidification process Objective: homogeneous temperature distribution (a prerequisite for the quality of castings) Solidification process Objective: oriented solidification (a prerequisite for freedom of pores) Customer Benefits The undisputed advantage of using solidification simulation is the timesaving factor. Time-consuming oneto-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 accordance with the optimised results of solidification simulation, there is a very high probability that no complicated modifications 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. Exacast ceramic precision casting in hot moulds.

5 Extensive Material Skills Wolfensberger can consider specific customer requirements, thanks to its experienced team of metallurgists and modern materials laboratory. Starting at the development stage, our specialists work with your designers to prepare proposals for tailor made alloys which meet your specific needs. Hub Corrosion-resistant DUPLEX material 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 cobaltbased alloys. Thanks to the wide range of materials, the right steel or cast iron alloy can be found for almost any application. Stainless Steel Alloys Wolfensberger casts all the major stainless steel alloys: corrosion-, rust- and acid-resistant, highly creep-resistant and wear-resistant. Highly alloyed cast steel allows the costeffective 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 technological 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 Nozzle ring Heat-resistant cast steel or nickel-based alloys Wear resistant cast iron alloys Wear resistant cast iron alloys (high chromium 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. 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 R m 104 h, MPa Austenitic steels Superferritic steels Ti alloys Ni-based alloys Ferritic-austenitic steels 300 Austenitic steels Refractory alloys Nickel-martensitic steels 200 Ferritic steels Martensitic steels Strength 100 Bainiticmartensitic Co-based alloys steels Temp. C

6 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 Plant 2 with chipping and refinishing shop for castings. 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 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 machinability and castability, etc.). In-house machining. Our quality depends upon the commitment of each and every employee. 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 symmetrical and cubic parts In-house face and profile grinding shop Subcontracted finishing of parts or semifinished products 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) Microstructural tests are carried out in our metallurgical laboratory. HIGH GRADE STEEL & PRECISION CASTING Wolfensberger AG Bäretswilerstrasse 45, CH-8494 Bauma T , F wag@wolfensberger.ch