30CrMnSiA合金前端吊耳断裂原因分析

Fracture causes analysis of front lifting lug of 30CrMnSiA alloy

某30CrMnSiA合金前端吊耳发生断裂,对断裂吊耳进行断裂特征分析和硬度测试。结果表明,吊耳断裂性质为氢脆断裂,且存在硬度超标现象。结合吊耳热处理和表面处理工艺对氢脆断裂原因进行分析,表面处理过程中除氢不彻底是造成氢脆的主要原因,而硬度超标不仅增加氢脆敏感性,且误导除氢工艺;同时该失效件反映了供应商质量控制上的不足,需在特殊过程及二次外包上加强控制和审核力度。

A front lifting lug made of 30 CrMnSiA alloy was broken and failed, whose fracture characteristics were analyzed and the hardness test was carried out. The results show that the fracture of the lifting lug is hydrogen embrittlement fracture and there is a phenomenon of excessive hardness. By combining the lug heat treatment and surface treatment process, it shows that incomplete hydrogen removal during surface treatment is the main cause of hydrogen embrittlement. Excessive hardness not only increases hydrogen embrittlement sensitivity, but also misleads the dehydrogenation process, so it is necessary for the lifting lugs to avoid excessive hardness. At the same time, the failure event reflects the lack of supplier quality control, and it is necessary to strengthen control and audit efforts in special processes and secondary outsourcing.