换热管表面堆焊铜覆层的焊接工艺

Welding technology of surfacing copper cladding on heat exchange tube

采用钨极气体保护焊(TIG)的方法,通过多组试验探索可行的焊接工艺方法,并结合产品堆焊实践改良,完成在T22,316L和800H这3种不同材料小直径换热管表面堆焊铜覆层。通过试验及实践可知,常规堆焊的方法用于T22换热管表面堆焊铜覆层,存在产生渗透裂纹的风险,但T22换热管堆焊时抵抗渗透裂纹产生的能力强于800H和316L换热管的;采用冷体堆焊可成功完成800H,T22及316L换热管表面堆焊铜覆层。3种不同材质换热管表面堆焊铜覆层的成功实施,为蒸汽发生器换热管内流动特性热工水力试验提供了有利条件。

Using the TIG welding method,the feasible welding method was explored through multiple groups of tests,and combined with the improvement of product surfacing practice,the copper cladding was completed on the surface of small-diameter heat exchange tubes of T22,316L and 800H. The test and practice showed that the conventional surfacing method was used for surfacing copper coating on the surface of T22 heat exchange tube,which had the risk of penetration crack,but the ability of resistance to penetration crack of T22 heat exchange tube was stronger than that of800H and 316L heat exchange tubes. The copper cladding on the surface of 800H,T22 and 316L heat exchange tubes could be successfully completed by cold body surfacing. The successful implementation of surfacing copper coating on the surface of heat exchange tubes of three different materials provided favorable conditions for the thermal and hydraulic test of flow characteristics in steam generator heat exchange tubes.