焊接参数对电站锅炉奥氏体钢小口径管焊接接头性能的影响

Effect of Welding Parameter on Properties of Austenitic Steel Tube Butt Joint of Boiler in Power Plant

本文选取超临界、超超临界电站锅炉受热面小口径管中SA-213 S30432、SA-213 T91+SA-213 TP347H两种典型的奥氏体同种钢及异种钢焊接接头进行了手工钨极氩弧焊常规焊接参数与非常规焊接参数的对比试验。试验结果显示,采用非常规参数的对接焊接接头在常温冲击韧性、断口检查、金相检验中出现了多种问题,而且由于RT无损检测的局限性,对小口径管对接焊缝中的未熔合等缺陷很难检出,造成电厂运行中的隐患。因此,奥氏体钢及其异种钢的手工钨极氩弧焊须合理选取焊接工艺参数,以获得良好的常温性能及内在质量,从而保证高温运行寿命。

Based on the contrast tests of commonly used welding parameter with uncommon one of manual GTAW, kinds of defects on charpy-impact, fracture and metallographic tests have appeared in tube butt joints of SA-213 S30432,SA-213 T91+SA-213 TP347H in SC and USC boilers.In addition, lack of fusion are hard to be detected by RT.These will become hidden dangers for the servicing power plant. To ensure service life of power plant, reasonable selection of manual GTAW welding parameter is more important for guarantee of properties and quality of similar and dissimilar butt joints of austenitic steel.