通过宏观检验、化学成分分析、硬度测试、金相检验和断口分析等方法对65Mn钢弹簧垫圈的开裂原因进行了分析。结果表明: 该垫圈氢含量较高, 服役时大部分区域处于悬空状态, 造成垫圈变形不均匀, 形成应力集中。另外, 垫圈凸面的防滑压花以及压花边缘的轮廓线处也存在应力集中, 氢原子容易在此聚集, 最终导致垫圈发生了氢致延迟脆性开裂。

The cracking reason of 65Mn spring washers were analyzed by means of macroscopic examination, chemical composition analysis, hardness testing, metallographic examination, fracture analysis and so on. The results showed that hydrogen content in the spring washer was high, and the majority of spring washer was at the hanging condition under their serves, which caused non-uniform deformation, and formed stress concentration. Moreover, the convex skid-prevention embossing as well as the edge contour line of embossing also had stress concentration, where hydrogen atoms easily accumulated in. Finally, the spring washer resulted in hydrogen induced-brittle fracture.