Static strengths of spot-weld for thicker high-strength steel sheets

摘要

Static strengths of spot-weld are systematically studied for high-strength steel sheets, focusing on thicker grades. Tensile shear strength increases with sheet thickness and strength, although the fracture mode changes from tear to shear. Cross tensile strength also increases, but the variation with sheet strength is small and ductility ratio decreases. Welding with expulsion results in the decrease of cross tensile strength, especially for thicker sheets with higher strength or higher carbon contents.