The result shows that tempered martensite has apparent lath character when temper is between 740 ~ 780 , and the hardness of welded joint is 264 ~ 237hv , which can get better performance of the welded joint the lath character of martensite in welded joint disappears , and the carbide in the tempered sorbite of the base metal will aggregate when temper temperature is above 780 , and the hardness and plastic property will reduce obviously 结果表明，在740 ~ 780之间回火，焊缝硬度为264 ~ 237hv ，回火马氏体板条特征明显，可以获得优良的焊接接头性能；回火温度超过780 ，焊缝板条马氏体特征消失，母材回火索氏体中碳化物产生偏聚，硬度、塑性明显降低。
