Resistance spot welding method comprises first and third stages, in which secondary current is uncontrolled, and second stage in which it is controlled, current difference for first and third stages being used to assess weld quality

摘要

Resistance spot welding method is carried out in three stages. The secondary current is not controlled, but is measured, in the first and third stages. It is controlled in the second stage. The difference between the secondary current values in the first and third stages is used to assess the quality of the welds.