Technologies and strategies for efficient and flexible press hardening processes

Today, a continuously increasing complexity of equipment and processes characterizes the production technologies. This also applies to press hardening, a hot sheet metal forming process, for producing car body components with a high crash performance at low weight. Currently, the challenges in press hardening are not only limited to some single process steps. To increase the process reliability and flexibility, the products quality and the energy and resource efficiency all process steps and its technologies need to be investigated in the context of the whole process chain. Therefore, the paper gives an overview about alternative approaches for an optimized press hardening process, including pre- and post-processing plus the forming and quenching process. It starts with investigations on direct contact heating, which enables fast and flexible austenitization of sheet metals at compact machinery dimensions. Furthermore, the paper presents new approaches on press hardening tool technologies, especially focused on design of cooling channels for high cooling rates. As an alternative to laser cutting technologies, the paper presents the process integrated mechanical trimming of press hardened car body parts via high speed impact cutting. Finally, the approach and experimental results for a feedback controlled press hardening process are presented. Combined with stroke-to-stroke control based on measuring of process-relevant parameters, a readjustment of the production line is possible in order to produce each part with individual, optimal process parameters to realize zero defect production of property-graded press hardened components with constant high part quality