PRESS HARDENED STEEL WITH TAILORED PROPERTIES AFTER NOVEL THERMAL TREATMENT

A tailor-welded blank is created by forming a blank from a steel of composition A and a steel of composition B and welding said two steels together, heating said welded blank to a temperature above the Ac1 temperature associated with the steel of composition A, transferring said blank to a forming die, and then cooling said blank to a temperature between the martensite start temperature and martensite finish temperature of the steel of composition B and holding said blank at such temperature or at a higher temperature, cooling said blank to room temperature. The tailor-welded blank comprises Alloy A and Alloy B, wherein Alloy A comprises 0.10-0.50 wt % C, 0.1-0.5 wt % Si, 2.0-8.0 wt % Mn, 0-6.0 wt % Cr, 0.0-2 wt % Mo, and 0.0-0.005 wt % B and wherein Alloy B comprises 0.06-0.12 wt % C, 0.1-0.25 wt % Si, 1.65-2.42 wt % Mn, 0.0-0.70 wt % Cr, 0.08-0.40 wt % Mo, 0.0-0.05 wt % V, 0.01-0.05 wt % Ti, and 2 wt % Al or less, and wherein said tailor-welded blank is subject to a quench and partition thermal cycle in a forming die.