Al-Mg alloy is a strong candidate material for automotive body parts because it does not require heat treatment and has excellent ductility. However, the hot-tearing susceptibility of Al-Mg based alloy is higher than the conventional Al-Si based alloy. In this study, alloys added with Al-4.5%Mg and 1.0%Mn and alloys added with Al-4.5%Mg, 1.0%Mn, 0.12%Si, 0.08%Ti, and 0.016%B were prepared, and the influence of Sr addition in the range of 0 and 0.04% on the hot-tearing susceptibility of both alloys was systematically investigated. The I-beam test in which both ends of the test piece are constrained was used to evaluate the hot-tearing susceptibility. The result suggested that there is no influence of the addition of Sr alone without the presence of Si, Ti, B. On the other hand, in the presence of 0.12%Si, 0.08%Ti, and 0.016%B, the hot-tearing susceptibility reduced when the Sr addition was higher than 0.004%.
