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.
Some ships do sail with armed guards, but their small-calibre weapons would be hard put to stop a reinforced drone boat whipping across the waves, according to Mr Crino.
口径薄壁管固定口仰焊部位易出现气孔、
穿、塌陷及焊接热裂纹等问题,分析问题存
因,从焊接工艺方面入手,提出一套消除气孔及
器
收效甚微。
表示，有些船只确实配备了
