Study on the strength and failure modes of laser welded galvanized DP980 steel lap joints

摘要

The mechanical properties of different sections of the laser welded galvanized high strength dual phase (DP) 980 steel lap joint such as the hardened zone (fusion zone and the grain coarsened heat affected zone (HAZ)), the softened zone (subcritical HAZ), and the base material were determined through mini-tensile tests. The numerically-predicted load-displacement curve and the sample rotation angle were verified by experimental measurements. The FE model considering the non-homogeneous mechanical properties was built based on the weld cross section geometries that were obtained under various laser welding conditions. The numerically-predicted von Mises equivalent strain concentrations and failure modes of the galvanized DP980 lap joints with respect to different laser welding conditions exhibit reasonable agreement with the experimental results.