易塌陷的

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部位易出现气孔、烧穿、塌陷及热裂纹等题,题存在原因,从艺方面入手,提出一套消除气孔及烧穿操作手法。