某不锈钢弯头在使用中发生泄漏。通过化学成分分析、金相检验、力学性能测试、扫描电镜和能谱分析以及晶间腐蚀试验等手段对不锈钢弯头开裂的原因进行了分析。结果表明: 弯头外壁所在环境中存在腐蚀性介质, 在环境介质、残余应力与工作应力的共同作用下, 弯头产生了沿晶应力腐蚀开裂。

A tee elbow of stainless steel was leaked during operation. By means of chemical composition analysis, metallographic examination, mechanical property testing, SEM and EDS analysis, intercrystalline corrosion test and so on, the cracking cause of tee elbow was analyzed. The results showed that there was corrosive medium existed in the environment where tee elbow worked; the environmental medium, residual stress and operating stress led to intergranular stress corrosion cracking on the tee elbow.