As welding is conducted for the mediumcarbon alloy steels using austenitic electrodes, two kinds of cracks,hot crack and fusion zone crack,can be found in backing weld of dissimiar metal weld.

• 采用奥氏体焊条焊接中碳合金钢时,发现了两种形态的裂纹:底层焊道中的热裂纹和熔合区裂纹。