Evaluation of main influencing parameters on the distortion of press hardened components with tailored properties based on statistical methods

Press hardening is one of the key technologies for the production of crash relevant parts in auto-motive industry. In contrast to completely hardened parts such as bumpers or side impact beams, a process modification allows for parts with tailored properties. These parts include areas of high strength and areas of high formability, that are intended to absorb crash energy. Tailored proper-ties can be achieved by a localised prevention of the cooling-related martensite transformation during the forming process. For this purpose, the forming tool is locally equipped with heating elements. Due to a non-uniform temperature distribution, the final part geometry results from a complex interaction of microstructure evolution, shrinkage and localized spring back. To achieve high geometric accuracy, a comprehensive knowledge of the interaction and associated control of the mechanical and thermal process conditions is required. To gain advanced knowledge about the process and to identify those process parameters, which mainly influence component distor-tion, a parameter study is performed. Statistical methods allows for an analysis of process data and a derivation of interactions.