油气管道环焊缝焊接施工应关注的问题及建议

Focus on Problems and Suggestions of Oil and Gas Pipeline Circumferential Weld Welding at Site Construction

随着管道建设用钢管强度等级的提高,环焊缝越来越成为制约管道焊接施工的关键环节。笔者提出了连头焊接、返修焊接、高寒地区冬季施工及特殊地质条件下环焊缝应力状态等油气管道现场焊接施工中应关注的问题,阐述了连头和返修的术语定义,对比国内外冬季施工的标准规定和实际经验,对环焊缝在不同载荷条件下的应力状态进行了分析,并结合目前的管道建设现状给出了相应的焊接建议,如连头根焊宜采用上向焊、返修焊接不应采用自保护药芯焊丝、冬季焊接施工可行但应提前做好防护准备、承受侧向应力的环焊缝应采用高强匹配焊接工艺等。

Along with steel pipe strength grade increasing applied for pipeline construction, the circumferential weld increasingly become the key link of pipeline welding construction. In this article, it put forward some focus on problems in site welding construction of oil and gas pipeline, such as butt welding, repair welding, winter construction in alpine region and circumferential weld stress condition under particular geological conditions, the term definition of butt welding and repair welding were introduced. It compared standard requirements and practical experience in winter construction at home and abroad, analyzed stress state of circumferential weld under different load, and gave corresponding welding suggestions, combining with present pipeline construction status, such as adopting up-welding in root welding; For repair welding, the welding is not applicable using self-protection flux-cored wire;For winter welding construction in pipeline, it can be executed under the condition of protection preparation;Circumferential weld undergoing side stress should adopt high and strength matching welding procedure.