Characterization and modelling of soft zones around spot welds in high strength steels

The aim of this work is to find a general correlation to describe the reduction in strength of spot welded sheet metals made out of hot-stamped 22MnB5 in relation to the geometrical dimensions of the softened heat affected zone. Tensile tests with spot welded microstructure in the measurement length of the specimen were conducted and used for validation purposes. The resulting analytical model was derived in [1], [2] from a model by Satoh [3] for seam welded plates with a soft interlayer under tensile loading. The derived model was experimentally and numerically validated for different values of the relative thickness of the softened heat affected zone.