Speaker
Description
Press hardening grades are widely used in automotive industries for safety-critical structural parts due to its unique combination of high strength, excellent formability, and crash performance. Although general process windows are recommended by steel suppliers, achieving the targeted strength and ductility / fracture strain in the hot-stamped parts is still challenging to some hot stampers for some grades. In this investigation, a dilatometer study for Usibor@1500 and two emerging grades Usibor@2000 and Ductibor@1000 under hot stamping condition was conducted with consideration of the entire hot-stamping processes (i.e., austenitization, blank transfer, forming and final quenching) to understand the differences in critical cooling rates, and evolution of microstructures. Influence of forming strain on final properties is also examined for Ductibor@1000 by DIL 805 A/D dilatometer under tensile deformation mode. In-situ observation of microstructural evolution during hot stamping process is explored using Confocal scanning laser microscope to further fine-tune customer hot stamping practices.