不锈钢管道使用5 a(年)后出现泄漏事故。采用化学成分分析、硬度测试、金相检验、晶间腐蚀与断口扫描电镜分析方法, 对泄漏原因进行了分析。结果表明: 焊接过程中造成的贫铬及残余应力的存在导致了管道的开裂。建议对管道所有焊缝热影响区进行探伤, 查找腐蚀裂纹, 对发现的裂纹进行打磨和补焊处理, 并进行消除残余应力处理。

The pipe leaked in use after five years. The leakage reason of the pipe was analyzed by means of chemical composition analysis, hardness testing, metallographic examination, intergranular corrosion analysis and fracture SEM analysis. The results showed that chromium depletion in heat-affected zone during the welding process and the residual stress led to the pipeline cracking. It was suggested that all of the welding seam should be inspected nondestructively to find corrosion cracks, and the cracks should be grinded and repaired by welding processing, and the residual stress should be eliminated.