热时效对Sanicro25钢/P92钢异种钢焊接接头组织及元素迁移的影响  

Effect of thermal aging on microstructure and element migration of Sanicro25 steel/P92 steel dissimilar steel welded joint

作　　者：赵志航 申俊杰[1,2] 李博[1,2] 阮涛涛 ZHAO Zhihang;SHEN Junjie;LI Bo;RUAN Taotao(Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control,Tianjin University of Technology,Tianjin 300384,China;National Demonstration Center for Experimental Mechanical and Electrical Engineering Education,Tianjin University of Technology,Tianjin 300384,China)

机构地区：[1]天津理工大学天津市先进机电系统设计与智能控制重点实验室,天津300384 [2]天津理工大学机电工程国家级实验教学示范中心,天津300384

出　　处：《天津理工大学学报》2025年第1期1-9,共9页Journal of Tianjin University of Technology

基　　金：国家自然科学基金(51605330)。

摘　　要：异种焊焊接部长期服役下的组织演变及元素迁移会对其服役安全性产生影响。文中采用钨极惰性气体保护焊对Sanicro25/P92钢进行焊接,焊丝选用ERNiCrMo-3。将焊接接头在650℃下时效0,500,2 000 h后,观察热时效对焊接接头组织演变和元素迁移的影响。结果表明:焊接部中不同区域的微观组织存在较大差异。P92钢的组织分为P92钢热影响区(heat affected zone, HAZ)和P92钢非热影响区(non-heat affected zone, Non-HAZ),时效后组织中的晶粒尺寸增大,Laves相的数量增多,Laves相主要分布在晶界上;在焊接部P92钢粗晶热影响区(coarse grained heat affected zone, CGHAZ)中观察到δ铁素体,时效后δ铁素体数量逐渐增多形成δ铁素体带。Sanicro25钢和焊缝的组织分别是奥氏体晶粒和树枝状结构,热时效后Sanicro25钢的组织变化不明显,焊缝中的枝状结构更加清晰。在P92钢和焊缝的交界处出现元素迁移,时效2 000 h后元素迁移趋于稳定。时效后,焊接部P92钢CGHAZ的硬度值下降最多。The microstructure changes and element migration of the dissimilar welded joints after aging will have an impact on its service safety.In this paper,Tungsten Inert Gas welding was used to weld Sanicro25/P92,the welding wire is ERNiCrCoMo-3.The welded joints were aged at 650°C for 500,1000,and 2000 h,and then observe the effect of aging on microstructure evolution and element migration of welded joints.The results show that the micro-organization varies greatly in different regions of the welding section.The microstructure of P92 steel is divided into P92 steel heat-affected zone(HAZ)and P92 steel non-heat-affected zone(Non-HAZ).After aging,the grain size in the microstructure increases,and the number of Laves phases increases,mainly distributed on the crystal boundary;And theδferrite was observed in P92 CGHAZ of the welding,after aging,the number ofδferite gradually increased to form theδferite region.The microstructure of Sanicro25 steel and weld are austenitic grain and dendritic structures,respectively.The obvious change of the microstructure of Sanicro25 steel does not occur after the aging,and the crystal boundary in the weld microstructure is more obvious.Element migration occurred at the interface between P92 steel and weld.After aging for 2000 h,the element migration tended to be stable.After aging,the hardness of the welding section P92 CGHAZ decreases at most.

关 键 词：Sanicro25钢 P92钢 异种焊 微观组织 元素迁移 

分 类 号：TG47[金属学及工艺—焊接]