基于E81T8-Ni2填充盖面的L415M管线钢的焊接工艺评定

Welding Procedure Qualification for L415M Pipeline Steel Based on Filling and Cap Welding of E81T8-Ni2

L415M管线钢环向焊接接头焊接工艺填充盖面焊丝采用E81T8-Ni2代替E71T8-Ni1,替代原则不符合GB/T 31032—2014《钢质管道焊接及验收》的覆盖原则,需要重新进行焊接工艺评定。基于施工单位焊接工艺需求,为了验证E81T8-Ni2能否用于L415M对接焊缝的填充盖面焊接,采用焊条电弧焊打底,自保护药芯焊丝半自动焊填充盖面组合焊接方法,根焊焊接材料为E6010,填充盖面为E81T8-Ni2,依据GB/T31032—2014进行焊接工艺评定。对评定试样进行外观检查、无损检测、拉伸试验、弯曲试验、刻槽锤断试验以及冲击试验。试验结果表明,L415M管线钢环向焊接接头各项指标合格,拉伸试样断在母材上,焊接接头满足高强匹配要求。焊接工艺评定试验研究成果可为长输管道用L415M管线钢焊接工艺以及焊材选择提供参考。

E81T8-Ni2 was used to replace E71T8-Ni1 on filling and cap welding of welding wire for L415M pipeline steel girth welding joint in welding procedure.The replacement principle does not conform to the covering principle of GB/T 31032—2014“Welding and acceptance standard for steel pipings and pipelines”,welding procedure qualification must be carried out again.Based on the welding procedure requirements of the construction unit,in order to verify whether E81T8-Ni2 can be used for filling and cap welding of L415M butt weld,the combined welding method of electrode arc welding and self-protection flux cored wire semi-automatic filling and cap welding was adopted.The welding material of root bead was E6010,filling and cap welding was E81T8-Ni2,welding procedure was qualified according to GB/T 31032—2014.Appearance inspection,non-destructive testing,tensile test,bending test,notching hammer test and impact test were carried out on the assessed specimens.The test results show that the circular welded joints of L415M pipeline steel were qualified,the tensile sample was broken on the base material,and the welded joints meet the requirements of high strength matching.The results of welding procedure qualification test can provide reference for the selection of welding procedure and welding material of L415M pipeline steel for long-distance pipeline.