汽车发动机盖锁扣断裂原因及改进措施

Fracture Cause and Improvement Measure of Locker on Automotive Engine Cover

某种车型的发动机盖锁扣在总装过程中发生断裂失效。通过化学成分分析、金相检验和力学性能测试等方法对锁扣断裂的原因进行了分析。结果表明:所用的SCM435钢为未球化退火状态,材料硬度过大,以及镀锌过程中可能引起氢脆等原因导致锁扣断裂。通过改变材料球化退火状态,以及改进加工工艺,解决了锁扣断裂问题。

Fracture failure of locker on one automotive engine cover was occurred. By means of chemical composition analysis, metallographic examination, mechanical properties testing and so on, the fracture cause of the locker were studied. The results showed that the material of SCM435 steel was not treated by spheroidizing annealing, the hardness of material was high, and there was hydrogen embrittlement in galvanized process, resulted in locker fracture. The problem of fracture failure was solved by replacing spheroidizing annealing treatment for 8CM435 steel, and improving processing technology.