| 摘要 |
PROBLEM TO BE SOLVED: To provide a resistance spot welding method of a high-strength steel sheet, which is excellent in tensile property of a joint. SOLUTION: In the resistance spot welding method, an electric current is made to flow to perform welding while a set of sheets having two or more high-strength steel sheets superimposed is held between a pair of electrodes, and a pressure force is added. The resistance spot welding is performed in a process including a first step of forming a nugget by main energization, a second step of cooling a weld zone by holding the set clamped with the electrodes after the completion of the first step and, after the completion of the second step, a third step of making an electric current flow that is higher than the main energization in an extremely short time within a range producing no expulsion. COPYRIGHT: (C)2010,JPO&INPIT |
