关键词: 热成型零件；电阻点焊；感应退火

Abstract: With the higher requirement of automobile lightweight and safety, more and more hot stamping parts be used in body in white because of their very high strength. For hot stamping parts, the strength of heat-affected zone (HAZ) will be lower after resistance spot welding due to insufficient cooling. The small heat affected zone will cause stress concentration. In the pole crash testing, the hot stamping A-pillar reinforcement is easy to crack from the heat affected zone. In order to solve the crack issue, the A-pillar reinforcement can adopt the external induction annealing. After the induction annealing, the strength of welded flange is the same as that of heat affected zone, so as to eliminate the problem of stress concentration in heat affected zone. The results of computer aided engineering analysis show that the problem of collision cracking can be solved by induction heating without increasing the thickness and weight of parts.

Key words: Hot stamping parts; Resistance spot welding; Induction annealing