管道自由口连头自动焊接工艺

Automatic welding process of pipeline shifting tie-in

为了提高管道自由口连头的焊接质量和焊接效率,降低人工劳动强度,采用CPP900-W1A单焊枪管道自动焊进行自由口连头焊接试验。试验优化并设计了双V形复合坡口,根据相控阵超声波检测(Phased array ultrasound testing,PAUT)、射线检测(Radiographic testing,RT)结果和焊接缺陷的宏观金相形貌,对接头典型缺陷进行了分析,优化了施工方法和焊接工艺,进行了焊接工艺的焊接时效验证和焊接接头力学性能测试。结果表明,双V形坡口相比单V形坡口可减少金属填充量约30%;采用实心焊丝气体保护下向焊(根焊、热焊)+药芯焊丝气体保护上向焊(填充焊、盖面焊)工艺的焊接用时为2.8~3.5 h,相比传统连头工艺的焊接可节省时间约50%,采用该焊接工艺连续焊接5道口并检测合格,焊接接头力学性能均满足工艺规程的相关标准要求,试验得到了满足管道自由口连头的焊接施工方法和焊接工艺,为中俄东线管道自由口连头焊接提供了高效、可靠的焊接工艺。

In order to improve welding quality,welding efficiency of pipeline shifting tie-in and reduce labor intensity,CPP900-W1A automatic welding with single welding gun pipeline was used for welding of pipeline shifting tie-in in the experiment.Double V-shaped groove was designed optimally by the test.Combined with results of phased array ultrasound testing(PAUT),radiographic testing(RT)and macroscopic metallographic morphology of weld defects,typical defects of welded joints were analyzed,construction methods and process methods were optimized,and welding efficiency verification and mechanical properties of welded joints were carried out.The experiment results showed that compared with single V-shaped groove,double-V groove reduced filling amount by about 30%.For adopting welding process of solid wire gas shielded downward welding(root welding,hot welding)and flux-cored wire gas shielded upward welding(fill welding,cover welding),welding time was 2.8~3.5 h.Compared with traditional welding process,it saved about 50%of welding time.The welding process was used to weld five joints continuously,welded joints were qualified by inspection,and mechanical properties of welded joints meet requirements of relevant standards.The construction method and welding process that satisfied pipeline shifting tie-in were obtained,which provided an efficient and reliable welding process for shifting tie-in of East China-Russia gas pipeline.