Development of Cold-stamped Door Impact Beams Made of 1180MPa Grade High Strength Steel Sheet

Abstract

Cold-stamped door impact beams made of TS1180MPa grade cold-rolled high strength steel have been developed. The newly developed parts achieved both of weight-reduction and cost-reduction from former hot-stamped parts. Cold-stamping is successfully performed by developing the high strength steel with high ductility. To avoid delayed fracture, the map which shows conditions (applied stress, strain and hydrogen) of the steel that hydrogen cracking occurs was drawn, and the condition of the parts was set far from the hydrogen cracking region.