| 摘要 |
PROBLEM TO BE SOLVED: To heighten bond strength between a light metal material and a steel plate more effectively and efficiently.SOLUTION: An aluminum-based material 1 and a steel material are superposed mutually, and sandwiched by a pair of electrodes 3a, 3b in this state, and each material is subjected to resistance spot welding by electric conduction into the electrodes 3a, 3b. In this case, a current is supplied to the electrodes 3a, 3b intermittently and dividedly into the first to fourth steps S1-S4 so that a current value is increased stepwise, and so that a current value I2 in the second step is increased as much as 20-40% of a current value I4 in the fourth step with respect to the first step S1. |
