短語詞組短語overhead d welding 仰焊overhead fillet welding 仰角焊overhead positions welding 仰焊仰焊overhead position welding 仰焊;氧焊;仰臉焊horizontal overhead position welding 仰角焊overhead welding seam 仰焊縫overhead position of welding 仰焊位置welding in overhead position 仰焊 返回 overhead welding