ELECTRODE FOR RESISTANCE SPOT WELDING AND METHOD FOR RESISTANCE SPOT WELDING USING THE SAME

摘要

PURPOSE: A resistance spot welding electrode and a resistance spot welding method using the same are provided to increase a current flowing area, to minimize the generation of expulsion, and to remarkably increase the rigidity of a welded part by containing a ring-shaped protrusion structure protruding from an opposite surface facing a base welding material and surrounding the central part of the opposite surface. CONSTITUTION: A resistance spot welding electrode includes a ring-shaped protrusion structure(24) protruding from an opposite surface(25) facing a base welding material(12,14) and surrounding the central part of the opposite surface. The protrusion structure includes a first part(24a) and a second part(24b). The cross-sectional diameter of the first part in a direction parallel to the opposite surface is increased constantly. The second part is formed at the end part of the first part and touches the base welding material, and has a curvature radius. A groove(22), recessed from the center of the opposite surface to the opposite direction from the base welding material, is formed in order to facilitate a dressing process removing a contamination layer generated by repeated welding. Pressure is applied and a current flows to the base welding material through the protrusion structure in order to form a nugget at the base welding material corresponding to the protrusion structure.