长时服役后的T23管与T91新管焊接接头组织与性能研究  

Microstructure and Properties of Welded Joints between T23 Tube after Long-term Service and New T91 Tube

作　　者：李晋刚 朱建强 栾高灿 景江峰 夏咸喜 张向前 LI Jingang;ZHU Jianqiang;LUAN Gaocan;JING Jiangfeng;XIA Xianxi;ZHANG Xiangqian(Hejin Power Generation Branch of Jinneng Holding Shanxi Electric Power Co.,Ltd.,Hejin 043300,China;Suzhou Nuclear Power Research Institute,Suzhou 215004,China)

机构地区：[1]晋能控股山西电力股份有限公司河津发电分公司,山西河津043300 [2]苏州热工研究院有限公司,江苏苏州215004

出　　处：《热加工工艺》2023年第9期66-71,共6页Hot Working Technology

摘　　要：某电厂末级过热器管材质为T23钢,在服役13.5万小时后整体更换为T91钢。为掌握长期服役后的T23与T91新管焊接接头的焊接质量,为电厂的长期运行以及同类电厂的换管改造提供数据支撑,模拟了现场焊接工艺,对T23与T91管进行焊接,对焊后接头的组织与性能进行研究。结果表明:焊缝与T23和T91两侧熔合良好,T23侧热影响区为室温、高温拉伸的性能薄弱区,接头强度与T23母材相比未发生明显下降。焊接过程中,T23侧粗晶区的第二相溶入母材,冷却后析出相少,而细晶区析出相长大粗化。盖面焊层焊缝硬度高于打底焊层,二者的热影响区硬度相近。利用等温线外推法外推计算焊接接头的剩余寿命,剩余蠕变寿命大于5万小时,满足电厂服役要求。The material of the final superheater tube of a power plant is T23 steel,and it is replaced with T91 after 135,000 h of service.In order to master the welding quality of the welded joint between T23 pipe after long-term service and T91 new pipe and provide data for the long-term operation of power plant and the pipe replacement transformation of similar power plants,the field welding process was simulated to weld T23 and T91 pipes,and the microstructure and properties of the welded joint were studied.The results show that the weld fuses well with both sides of T23 and T91,the heat affected zone at the T23 side is the weak area during room temperature and high temperature tensile tests,and the joint strength does not decrease significantly compared with that of the T23 base metal.During the welding process,the secondary phase in the coarse grained region at the T23 side melts into the base metal,the precipitated phase content decreases,while the precipitated phases in the fine grained region grow and coarsen.The hardness of the cover welding layer is higher than that of the bottom welding layer,and the hardness of the heat affected zone of the both layers is similar.Using the isotherm extrapolation method to extrapolate the remaining life of the welded joint,the remaining creep life is bigger than 50000 h,which meets the service requirements of power plant.

关 键 词：异种钢接头 T91钢 T23钢 显微组织 力学性能 

分 类 号：TG444[金属学及工艺—焊接]