近年来,对流受热面异种金属焊接的焊缝缺陷已变得越来越普遍。绝大多数的过热器以及输送蒸汽温度在538℃或538℃以上的再热器都是采用两种不同金属的管系,在高温区采用奥氏体不锈钢管系,而在低温区则采用铁素体钢管系。尽管这些管系的焊缝接头设计、焊接工艺、焊接金属可以各有不同,但是在焊缝交界面附近的铁素体材料上常常出现裂缝,具有异种钢焊接接头的两种典型的对流受热面的布置如图1所示。关于异种金属焊接的焊缝缺陷,通过对 In recent years, weld defects on heat transfer dissimilar metal surfaces have become more and more common. Most superheaters and reheaters that deliver steam at 538 ° C or 538 ° C are made from two different metal pipe systems, austenitic stainless steel tubing at high temperatures, and iron at low temperatures Element steel pipe system. Although the weld joint design, welding process, and weld metal for each of these pipe systems can vary, fractures often occur on the ferritic material near the weld interface, with two typical convective heating surfaces with dissimilar steel welded joints The layout shown in Figure 1. On dissimilar metal welding weld defects, by right