滤清器外壳安装在汽车发动机台架上试验500 h后出现裂纹,采用宏观和微观分析、化学成分分析和金相检验等方法对开裂原因进行了分析。结果表明: 滤清器外壳的外壁局部区域在拉延时产生了微裂纹,在交变应力作用下形成疲劳裂纹，并导致早期疲劳开裂。

Crack was found after the filter case was installed on the engine pedestal and tested for 500 hours. Cracked filter case was analyzed by means of macroscopic and microscopic analysis, chemical composition analysis and metallographic examination. The results showed that the microcrack on the local position of case caused the fatigue crack initiation under the action of alternating stress and led to early fatigue cracking.