Forming of an axially tailored automotive channel section through hot stamping of tailor-welded blanks

In this work, top-hat cross-section axial crush rail specimens with tailored properties along their length were investigated. These top-hat channels were hot stamped in a fully cooled die set from tailor-welded blanks (TWBs). The blanks were laser-welded and comprised Usibor (R) 1500-AS joined to Ductibor (R) 500-AS in 1.2 mm and 1.6 mm thicknesses. Micro-hardness measurements were taken along the length of the formed specimens to map the hardness profile along their length. The effect of gauge thickness on hardness was evaluated. The hardness profile of these TWB parts was compared to that of parts formed using tailored in-die heating (IDH).