P 258 - Investigations into the applicability of hydrostatic forming processes for the production of stiffened, flat, lightweight moulded components and stamped parts made of sheet steel

Using 7 secondary forming elements and over 20 sheet materials in the thickness range from 0.2 to 1.5 mm - unalloyed deep-drawing sheets, stainless steels, metallic and organically coated steels as well as an aluminium alloy - the forming behaviour during hydrostatic stretch forming was investigated mathematically and practically. To determine the forming limits, certain sheet metal moulded parts and secondary forming elements such as the spherical cap, groove, square cusp, round cusp, honeycomb, kidney and conoid were selected for the tests. FEM simulation and experimental results on deformation and tearing behaviour were brought into good agreement. New technological expertise on the relationships between material characteristics and mould and process design was gained in numerous investigations. The combination of computer-aided and empirical findings on the hydrostatic stretch forming of secondary mould elements forms a technological and constructive basis for innovative product developments in lightweight construction. Possible applications for such sheet metal moulded products are seen in stiffening lightweight construction in automotive, vehicle, container and apparatus construction and, last but not least, for design products. The advantages of hydrostatic stretch forming, including increased forming capacity, surface-friendly sheet metal processing and improved component properties, make it possible to realise a wide range of new product ideas. New products already on the market based on the research carried out include structured stainless steel façade elements with a mirror finish, extractor bonnets in a new design and sheet metal moulded parts in special alloys for the aerospace industry. STUDIENGESELLSCHAFT STAHLANWENDUNG e.V.