某汽车雨刮臂在安装时于臂座处发生开裂。采用宏观分析、化学成分及硬度分析、扫描电镜（SEM）分析和金相检验等方法，对雨刮臂座开裂的原因进行了分析。结果表明：雨刮臂座存在冷隔缺陷和装配不当共同导致了雨刮臂座在装配时发生开裂，其中冷隔缺陷是主要因素；雨刮臂座中的冷隔缺陷是由于模具结构不合理及冷模件控制不当造成的。

The automobile wiper arm base cracking when it was installed. The cracking reasons of the wiper arm base were analyzed by means of macro analysis, chemical composition and hardness analysis, scanning electron microscopy (SEM) analysis, metallographic examination and so on. The results show that the cold shut defect and improper assembly caused the cracking of the wiper arm base in assembly, and the cold shut defect was the main factor. The cold shut defect in the wiper arm base was caused by improper mold structure and improper control of cooling module parts.