某汽车制动系统定子盘使用不到六个月即在焊接热影响区部位发生开裂,采用金相检验、化学成分分析、硬度测试及断口分析等方法对该定子盘开裂的原因进行了分析。结果表明:引起开裂的主要原因是焊接区域及母材应力集中严重,加上焊缝与母材熔合不良,定子盘在使用过程中承受扭力,最终造成了疲劳开裂。

The cracking occurred in the weld heat affected zone of a stator plate of automotive brake systems using less than six months. By means of metallographic examination, chemical composition analysis, hardness testing and fracture analysis, the cracking reason of stator plate was analyzed. The results showed that the main factors were severe stress concentration in weld zone and base metal, coupled with the bad fusion between the weld and base metal, and the stator plate withstand torque during use, eventually leading to fatigue cracking.