| 摘要 |
The objective of the invention is to provide a resistance spot welding method with which a nugget having a suitable diameter can be obtained even under special welding conditions, without increasing the energization time and without the generation of expulsions. The invention is a resistance spot welding method in which an energization pattern is divided into multi-stage steps having two or more stages, and in which test welding and main welding are performed. In the test welding, the energization is performed using a constant current that has a different current value for each step, and the time variation of the instantaneous amount of heat generated per unit volume, and the accumulated amount of heat generated per unit volume are stored as target values. In the main welding, if the amount of time variation of the instantaneous amount of heat generated per unit volume deviates from the results of the test welding during any step, the amount of energization is controlled in such a way that the difference is compensated for during the remaining energization time in said step. The configuration is such that in the test welding, if the energization current in a first step is Ia and the energization current in second and subsequent steps is Ix, the relationship 0.3 × Ix ‰¤ Ia < Ix is satisfied. |
