某高频直缝电阻焊管的泄漏原因

Reason for Leakage of a High-Frequency Electric Resistance Longitudinal Welded Pipe

某高频直缝电阻焊管发生天然气泄漏事故。通过宏观检验、无损检测、化学成分分析、力学性能测试、金相分析、扫描电镜及能谱分析等方法,研究了该焊管的泄漏原因。结果表明:焊接工艺不当导致此焊管焊缝中存在未熔合缺陷,且在焊管制造过程中因存在漏检问题而未被发现;未熔合缺陷在服役过程中发展形成泄漏孔,最终导致泄漏。

Natural gas leakage accident occurred in a high-frequency electric resistance longitudinal welded pipe.The leakage cause of the welded pipe was analyzed by macro-examination,non-destructive testing,chemical composition analysis,mechanical property test,metallographic analysis,scanning electron microscopy and energy spectrum analysis.The results show that incomplete fusion defects were produced in the weld of the welded pipe because of the improper welding process,and were not found by missing inspection during the manufacturing of the welded pipe.Therefore the incomplete fusion defects developed and formed leak holes in service,finally leading to the leakage.