Air hole, burnthrough, cooapse and welding crackle occurred in the fixed overhead weld for aluminium and aluminium alloy tubes, above all the small-size thin wall tube.

• 针对铝及铝合金管,特别是小口径薄壁管固定口仰焊部位易出现气孔、烧穿、塌陷及焊接热裂纹等问题,分析问题存在的原因,从焊接工艺方面入手,提出一套消除气孔及烧穿的操作手法。