9%Ni钢全自动TT立焊焊接工艺开发

Development of fully automatic TT vertical welding welding process for 9% Ni Steel

目前国内LNG储罐建造中的9%Ni钢立焊均采用焊条电弧焊,该焊接方法存在焊接效率低、劳动强度大、焊接烟尘对焊工人身危害较大等缺点。利用自主研发的小车进行9%Ni钢全自动TT立焊焊接工艺开发,通过控制盒控制焊接,大幅度降低了焊工的劳动强度和烟尘危害,提高了焊接效率。开发的焊接工艺采用无钝边、无间隙组对,降低了坡口加工要求,免去背面气保护,减少了背面清根量和焊缝填充量,节省了建造成本。无损检测及焊后理化性能试验结果表明,焊接接头性能优良,尤其是低温冲击韧性,从数值要求上看具有较大的裕量。

The welding process of 9%Ni steel on LNG tank in China is SMAW,its efficiency is low,the labor intensity is high and the welding fume is harm to welder. In this article,we use the automatic welding car to develop the vertical welding procedure of 9%Ni steel. Welding is controlled by a handheld box,the labor intensity of this welding process is lower than SMAW, but the welding efficiency is higher than SMAW, also there is little welding fume. The root face and root opening of the groove is zero.it reduces the machining request It doesn＇t need back shielded gas as welding,and reduces the amount of back root gouge and back filling. According to the result of NDT and mechanical test,the performance of the weld is excellent,especially on the CVN toughness,and it has a large margin from the numerical requirements,