WELDING STRUCTURAL MEMBER AND WELDING METHOD

摘要

Provided are: a welded structural member whose spot-welded part has both strength and ductility, and whose rupture strength proven by a rupture test such as a cross tensile test is high; and a method for welding such a structural member. The welded part 3 of the welded structural member 1 made of the above steel plates bonded by overlapping their faces and forming the welded part 3 by spot welding includes: a molten and solidified part 4; and a heat-affected zone 5 surrounding the molten and solidified part 4. The hardness on the welded surface increases to harder than the hardness of the steel plates 2 (base material) along a direction from a region outside the heat-affected zone 5 toward the heat-affected zone 5.

主权项

1. A welded structural member, comprising: steel plates bonded by overlapping the surfaces of the steel plates and forming a welded part by spot welding,
wherein the welded part contains: a molten and solidified part, and a heat-affected zone surrounding the molten and solidified part, and
the hardness on the welded surface increases, becoming higher than the hardness of the base material of the steel plates, along a direction from a region outside the heat-affected zone toward the heat-affected zone.