带垫板异种钢焊缝缺陷与拉伸性能分析  

Analysis on weld defects and tensile properties of dissimilar steel with backing plate

作　　者：汪峰 李梁[2] 徐刚[2] 张赵斐 李飞 徐敏 WANG Feng;LI Liang;XU Gang;ZHANG Zhaofei;LI Fei;XU Min(Nantong Power Plant of Huaneng International Power Co.,Ltd.,Nantong 226003,China;Xi’an Thermal Power Generation Co.,Ltd.,Xi’an 710054,China)

机构地区：[1]华能国际电力股份有限公司南通电厂,江苏南通226003 [2]西安热工研究院有限公司,陕西西安710054

出　　处：《热力发电》2023年第1期170-176,共7页Thermal Power Generation

基　　金：中国华能集团有限公司总部科技项目(HNKJ20-G01)。

摘　　要：异种钢焊接是电厂锅炉受热面管广泛采用的一种连接方式。以某火电机组过热器出口段TP304H和T22为母材的带垫板异种钢焊接接头为研究对象,通过宏观测量、微观组织分析、EDS能谱检测和拉伸试验等研究,分析了焊接接头中裂纹的生成机理及影响。结果表明:3种材料热膨胀系数差异及应力集中是带垫板异种钢焊缝裂纹产生的诱因,裂纹在镍基焊缝填充材料中扩展;室温拉伸时焊缝是薄弱环节,而高温拉伸时熔合线和母材是断裂部位。Welding of dissimilar steels is a widely used connection method for super-heater tubes of boilers in power plants. Taking the TP304H/T22 dissimilar steel welded joint with backing plate at the superheater outlet of a thermal power unit as the research object, the formation mechanism and influence of cracks in the welded joint are analyzed through macro measurement, microstructure analysis, EDS energy spectrum detection and tensile test. The results show that, the differences in thermal expansion coefficients of the three substrates and stress concentration are the cause of the cracks of the dissimilar steel weld with backing plate and crack propagation in nickel base weld filler.The weld is the weak link in room temperature tension, while the fusion line and base metal are the fracture parts in high temperature tension.

关 键 词：锅炉管 异种钢焊缝 裂纹 垫板 

分 类 号：TG441.7[金属学及工艺—焊接] TM621.2[电气工程—电力系统及自动化]