小规格埋弧焊钢管补焊工艺探讨

Discussion on Weld Repair of Small-sized SAW Steel Pipes

针对小规格埋弧焊钢管在进行单面焊双面成型补焊时存在的补焊焊缝质量差、易形成内焊瘤等问题,华北石油钢管厂在生产L360MB钢级Φ355.6mm×5.6mm埋弧焊钢管时采用了一种新的焊缝补焊工艺,即加装陶瓷衬垫+CO2气体保护焊打底+CO2气体保护焊(手工电弧焊)填充、盖面。采用该补焊工艺后,补焊的焊缝不仅成型良好,无内焊瘤,而且具有较好的力学性能,质量满足相关标准要求。

Addressing the problems relating to the single-side welding and dual-side formation weld repair of small-sized SAW steel pipes such as poor weld seam quality and tendency of internally overlapping, a newlydeveloped weld repair process is used by Huabei Petroleum Steel Pipe Plant for producing φ355.6 mm×5.6 mm SAW pipe in steel grade L360MB. The said process involves ceramic lining ＋ prime COL gas shielded welding ＋ filling and covering with CO2 gas shielded welding （manual electric arc welding）. Thanks to employment of this weld repair process, the weld-repaired seam is well formed and free of inner overlap, and possesses good mechanical properties, and the quality is up to relevant requirements of applicable standard.