卡箍螺栓螺母组合件失效分析

Failure analysis of clip bolt and nut assembly

为查明连接紧固汽车发动机涡轮增压器和三元催化器的卡箍螺栓螺母组合件失效原因,采用宏观检查、力学试验、横向振动、高温蠕变、化学分析等方法进行分析。结果表明:送检卡箍组合件的失效是由于高温下螺栓发生蠕变松弛导致螺母失去锁紧功能而引起的。提出避免螺栓发生蠕变松弛现象的改进措施。

Macroscopic examination, mechanical test, transverse vibration, high temperature creep and chemical analysis were used to analyze the failure reason of the clamp bolt nut assembly of the fixed automobile engine turbocbarger and the three element catalyst. The results show that the failure is caused by the creep relaxation of the bolt at high temperature, resulting in the loss of the locking function of the nut. The improvement measures to avoid creep relaxation of bolts are put forward.