Fatigue behavior of tailor (laser)-welded blanks for automotive applications

The drive towards weight reduction in the automotive industry has led to the use of tailor-welded blanks (TWBs) for structural applications. This work is aimed at evaluating the fatigue behavior of the TWBs having different thickness combinations and compositions with and without zinc coating. The results showed that TWBs made from zinc-coated/galvanized steels exhibited a lower fatigue limit as compared with the TWB combination from uncoated bare metals. This was attributed to the intergranular cracking in the galvanized TWBs caused by the presence of zinc penetrating beneath the sheet surface. The fracture surface of the uncoated TWB was basically characterized by the fatigue striations.