Development of carbon-manganese-chromium steels for automotive hot stamping technologies

摘要

The hot stamping potential of three commercial carbon-manganese-chromium steels was demonstrated. The steels were selected with the intention of producing ultrahigh strength ferritic-martensitic dual phase microstructures from hot stamping heat treatment, exhibiting superior tensile properties for 'impact energy absorptive' crash performance compared to the conventional carbon-manganese-boron steel for automotive hot stamping technologies, 22MnB5. Compared to 22MnB5, each of the carbon-manganese-chromium steels provided at least twice the total elongation, yet with a relatively small loss to ultimate tensile strength. It was concluded that the carbon-manganese-chromium steels provide superior tensile properties for impact energy absorptive crash performance, while exhibiting 'lean' chemical compositions compared to previously investigated steels with similar aims and offer opportunities for use in the 'tailor welded blank' concept.