A.表面氣孔B.夾渣C.弧坑裂縫D.電弧擦傷
A.減少缺陷的數(shù)量B.減少應(yīng)力集中C.確保焊縫的強(qiáng)度D.確保焊縫的搭接
A.0.5PB.0.75PC.1.25PD.1.5P