Patent ID: 9534268
Date: 2017-01-03
CPC Classifications: C21D,C22C

Claim:
1. A method for manufacturing a hot press-hardened vehicle body component, comprising the following production steps: a) heating a steel product produced at least in sections from a stainless steel comprising the following composition (specified in % wt.) C: 0.031-1.200%, P: up to 0.1%, S: up to 0.1%, Si: 0.10-1.5%, Cr: 10.5-20.0%, optionally, at least one element that promotes the formation of austenite selected from the group consisting of Mn: 0.10-3.0%, Ni: 0.05-8.50%, and Cu: 0.050-3.00%, and optionally one or more elements from the group “Mo, N, Ti, Nb, B, V, Al, Ca, As, Sn, Sb, Pb, Bi, H” with the requirement Mo: 0.05-2.50%, N: 0.01-0.2%, Ti: up to 0.02%, Nb: up to 0.1%, B: up to 0.1%, V: up to 0.2%, Al: 0.001-1.50%, Ca: 0.0005-0.003%, As: 0.003-0.015%, Sn: 0.003-0.01%, Sb: 0.002-0.01%, Pb: up to 0.01%, Bi: up to 0.01%, H: up to 0.0025%, remainder iron and unavoidable impurities to an austenisation temperature above the Ac3 temperature of the stainless steel, wherein the microstructure of the stainless steel is converted to a fully austenitic microstructure; b) hot press-hardening the heated steel product in a pressing die to form the vehicle body component; and c) cooling at least one section of the vehicle body component at a cooling rate that is high enough for a fully martensitic structure to form in each section that is rapidly cooled.