Bimetal girth weld of horizontally fixed composite pipe welding process and application research

水平固定复合管双金属环焊缝焊接工艺和应用研究 Bimetal girth weld of horizontally fixed composite pipe welding process and application research 穆学杰 MU Xuejie 1 first-author 孙宁松 SUN Ningsong 1 曲海涛 QU Haitao 1 田黎明 TIAN Liming 2 李广华 LI Guanghua 2 向琪月 XIANG Qiyue 1 牟宗浩 MOU Zonghao 1 宋元新 SONG Yuanxin 1 中石化胜利油田分公司 中石化胜利油田分公司 Shan dong Shengli Changlong Pipeline Technology Co.,Ltd. Shan dong Shengli Changlong Pipeline Technology Co.,Ltd. 山东胜利长龙管道科技有限公司  山东胜利长龙管道科技有限公司  SINOPEC Shengli Oilfield Co.,Ltd. SINOPEC Shengli Oilfield Co.,Ltd. 双金属复合管和耐蚀合金预制内补口钢管以其优异的耐腐蚀性能和免补口特点在油田中得到了广泛应用,特别是耐蚀合金预制内补口钢管造价相对低廉,近年来在国内油田高腐蚀地面管道中得到了较大面积的推广,效果良好。由于双金属复合管内、外层金属在化学成分、微观组织、物理性能等方面的差异,常用的对接焊接工艺存在工序复杂、操作难度大、施工成本高、焊工技能要求严的难题,容易造成成分偏析、耐蚀合金成分稀释、内焊道成形不良、虚焊、碳迁移和热输入引起的熔合区组织变化等结果。从影响双金属焊缝质量的因素出发,以不锈钢复合管水平固定对接焊为研究对象,从坡口形式、组对方式、耐蚀合金打底焊层和双金属过渡焊层的焊接方法等方面进行实验研究,提出了复合管内封焊、U型坡口无间隙组对、熔池背部保护、无填充熔化焊打底和无填充熔化焊过渡等新的工艺方法,通过X射线探伤和焊接工艺评定,并结合微观组织分析,对焊接工艺进行了综合评价。 Bi-metal composite pipe and corrosion-resistant alloy prefabricated inner-filled steel pipe have been widely used in oilfields due to their excellent corrosion resistance and performance-free joint characteristics. Especially the corrosionresistant alloy prefabricated inner-filled steel pipe is relatively inexpensive. In recent years,the cost has been promoted in a large area of high-corrosion ground pipelines in domestic oil fields,and has achieved very good results. Due to the differences in the chemical composition,microstructure,and physical properties of the inner and outer layers of the bimetal composite pipe, the commonly used butt welding process has the problems of complex procedures,difficult operation,high construction costs,and strict requirements for welder skills,which can easily cause composition segregation,dilution of corrosion-resistant alloy components,poor internal bead forming,false welding,carbon migration,and structural changes in the fusion zone caused by heat input. This article starts from the factors that affect the quality of bimetal welds,and takes the horizontal fixed butt welding of stainless steel composite pipes as the research object.Research and experiments have been carried out from the bevel form, the pairing method,the welding method of the corrosion-resistant alloy underlayer and the bimetal transition welding layer,and new process methods such as internal sealing of composite pipes,U-shaped groove free-space group pairing,back protection of the molten pool,unfilled fusion welding bottoming and unfilled fusion welding transition have been proposed.Through X-ray inspection and welding process evaluation,combined with microstructure analysis,comprehensively evalu-ated the welding process and concluded. 复合管 耐蚀合金预制内补口钢管 双金属焊缝 无填充熔化焊打底 无填充双金属过渡焊 TG457.6 2022-03-08 4 50