长输管道站场大型油泵法兰的焊接技术

Welding Technology of Large Oil Pump Flanges in Long Distance Transmission Pipeline Station

进口大型油泵法兰的材质大都执行欧洲或美国标准,焊工接触少,无成熟的焊接操作经验可借鉴。在确认法兰的材质后,根据LF2(法兰)、X52(管道)两种钢材的焊接特性,选择了ER50-6和E71T8-Ni1焊丝,采取GTAW+FCAW的工艺,在大庆-锦西原油管道梨树输油站,成功完成了4台德国进口输油泵的法兰与油管的焊接,焊缝经RT抽检合格。在简要介绍了母材的焊接性、法兰与油管焊接难点的基础上,较详细地论述了焊接方法的确定、焊前准备、GTAW打底焊、FCAW焊、返修焊技术,并针对该工程中易出现的焊接缺陷提出了相应的对策。该焊接经验对类似工程有一定的参考意义。

Most of the materials of the imported large oil pump flanges follow the European or American Standard, the welders are lack of relevant experience. After confirming the material of the flange and according to the welding characteristics of LF2 steel （ flange ） and X52 steel C pipeline） , ER50-6 and E71T8-Ni1 welding wires are selected and GTAW ＋ FCAW welding process is taken to weld pipelines and flanges of 4 oil pumps imported from Germany. The welds are qualified by RT random inspection. This paper introduces the base material weldability and welding difficulty between flange and pipeline, illustrates the determination of welding method, welding preparation, technique of GTAW backing welding, FCAW welding and rewelding, then provides the countermeasures for welding defects that easily occur in the project.