A comparison study on the effectiveness of stepped binder and weld line clamping pins on formability improvement for tailor-welded blanks

Forming of tailor-welded blanks (TWBs) is challenging frequently due to the unbalanced deformations in the thicker/stronger and thinner/weaker sides. While various process schemes have been developed to improve the TWB formability, their relative effectiveness is not clear. In this paper, the influences of stepped binder and weld line clamping pins on the formability of TWBs were evaluated via box drawing simulations and experiments. Process schemes of flat/stepped binder with/without clamping pins are compared addressing the formability measures, namely weld line movement, thickness reduction, and critical strain. It was shown that a combined use of stepped binder and clamping pins provides the best TWB forming quality.