Firstly, backing with double-sided in-phase welding, welding method is GTAW. Secondly, after filling outside one layer,welding with SAW. Finally, weld the inside with SAW.

• 先用双面同步焊打底，焊接方法为钨极氩弧焊；然后外侧用焊条电弧焊填充一遍后再用埋弧焊焊接；最后用埋弧焊焊接里侧。