TPi January 2012

stainless steel tubes

Cold forming: shaping the future for stainless steel

of cold formed austenitic and martensitic stainless steels that virtually eliminates galling. This manufacturing breakthrough has offered new opportunities and benefits for component manufacturers operating in a diverse range of sectors, from aerospace and automotive engineering through to medical, electronic and optical instruments. Unlike the traditional energy intensive, time consuming, wasteful or even hazardous methods of shaping metal, cold forming is a particularly simple process that produces metal com- ponents at low ambient temperatures without removing any material.

As a method of manufacturing precision components, cold forming has dipped under the radar of many engineers. However, the development of cold forming stainless steel looks set to revolutionise the way this material is manufactured, according to Mark Jennings, technical director at Dawson Shanahan. Cold forming has long been established as a method for producing simple, high volume components such as fasteners quickly and cost effectively. Increasingly, though, this process is being used to produce high precision components from a range of advanced engineered metals. More significantly, a new technique has now been developed by Dawson Shanahan enabling the production

Cold formed parts

length then using advanced mould and die sets, combined with extremely high levels of applied pressure (in excess of 600 tonnes), and extruded to the desired shape. By working with the material and eliminating the need for trimming and cutting, cold forming can cut waste by up to 80% in comparison with traditional machining processes. As cold forming is carried out at ambient temperatures, this high speed process can be completed 15 times faster than more conventional options, significantly saving on production time. As a result, components can be made precisely to order extremely quickly, cutting lead times and the need to store high volumes of spare parts on-site. Another advantage of producing components at ambient temperatures is the significant reduction in energy consumption, helping to reduce costs still further, as well as carbon footprint. Just as importantly, the cold forming process can improve the mechanical properties, with a finished part 18% stronger than that of machined components. Unlike machining, where sections are usually cut across the grain structure of the metal, the direction of forming and the geometry of the part are aligned with that of the grain. In addition, finished parts can have complex internal and external geometries, with exceptionally smooth surface finish, so that only minimal secondary processing is needed. This offers the potential for design engineers to specify components to a higher specification.

A typical cold forming press uses coiled wire at room temperature that is cut to

The cold forming process means faster output and lower energy consumption

While the technique has long been used with other advanced engineering metals

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Tube Products International January 2012

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