X60M钢管泄漏原因分析

Analysis on Leakage Reasons of the X60M Steel Pipe

X60M钢级螺旋缝埋弧焊钢管在管道试压过程中发生了泄漏,通过宏观检验、化学成分分析、力学性能测试、金相检验及能谱分析的方法,对其泄漏原因进行了分析。结果表明:板坯浇铸过程中熔渣卷入金属基体,并在后续的轧制过程中暴露于表面;在腐蚀性环境中熔渣周围形成点蚀,在自催化和氧浓差的作用下,点蚀坑逐渐扩展并最终导致管体穿孔及泄漏。

The X60 Mspiral submerged arc welded（SSAW）steel pipe with spiral seam was leaked during the pressure test.The leakage reasons were analyzed through the methods of macrographic examination,chemical composition analysis,mechanical property test,metallographic examination and energy spectrum analysis.The results show that：the slags got into the metal matrix during the slab casting process,and the slags exposed on the surface during the following rolling process;in the corrosive environment,corrosive pitting was formed around the slags,and under the action of the self catalysis and oxygen concentration difference,the corrosive pitting expanded gradually and finally led to the perforation and leakage of the steel pipe body.