焊接热循环及峰值温度对C-HRA-2镍基合金组织演变的影响  

Effect of Welding Thermal Cycle and Peak Temperature on Microstructure of C-HRA-2 Nickel-Based Alloy

作　　者：寇东旭 陈重毅[1] 陈正宗[2] 李永清 麻永林[1] 李一鸣[1,4] Kou Dongxu;Chen Zhongyi;Chen Zhengzong;Li Yongqing;Ma Yonglin;Li Yiming(School of Materials and Metallurgy,Inner Mongolia University of Science and Technology,Baotou 014010,China;Institute for Special Steels,Central Iron and Steel Research Institute Co.,Ltd,Beijing 100081,China;Technology Center,Inner Mongolia North Heavy Industries Group Co.,Ltd,Baotou 014033,China;Key Laboratory of Advanced Metals and Materials of Inner Mongolia,Inner Mongolia University of Science and Technology,Baotou 014010,China)

机构地区：[1]内蒙古科技大学材料与冶金学院,内蒙古包头014010 [2]钢铁研究总院有限公司特殊钢研究院,北京海淀100081 [3]内蒙古北方重工集团有限公司技术中心,内蒙古包头014033 [4]内蒙古科技大学内蒙古自治区新金属材料重点实验室,内蒙古包头014010

出　　处：《稀有金属材料与工程》2023年第7期2377-2384,共8页Rare Metal Materials and Engineering

基　　金：National Key R&D Program of China(2017YFB0305202);Inner Mongolia Natural Science Foundation(2016MS0510,2020MS05046);Key Technology Research Program of Inner Mongolia Autonomous Region(2021GG0047);Basic Scientific Research Business Cost Project of Colleges and Universities Directly Under the Inner Mongolia Autonomous Region in 2023。

摘　　要：通过焊接热模拟方法得到了C-HRA-2镍基合金在不同一次峰值温度(T_(p1)=1150,1250,1350℃)和二次峰值温度(T_(p2)=850,950,1050,1150,1250,1350,1450℃)下的焊接热影响区(HAZ),研究了峰值温度和热循环次数对C-HRA-2合金HAZ微观组织演变的影响,并测试了其显微硬度。采用光学显微镜、扫描电镜和透射电镜对HAZ的微观结构和碳化物进行表征。结果表明,在T_(p1)=1150℃的HAZ中,可观察到沿晶界析出的细小的M_(23)C_(6)碳化物。在T_(p1)>1250℃的HAZ中,在晶界附近发现由于成分液化而导致的γ基体与M_(23)C_(6)碳化物组成的微观结构。当T_(p2)在1050~1250℃,可在HAZ中的晶界附近观察到与在T_(p1)=1150℃的HAZ中类似结构的碳化物,这是由T_(p1)和T_(p2)间基体中Cr的固溶度差值导致的。在T_(p2)>1250℃的HAZ中,在晶界附近可观察到与在T_(p1)=1250℃的HAZ中类似的熔融态微观组织。随着T_(p2)的升高,显微硬度出现很大程度的起伏,在T_(p2)=1250℃的试样显微硬度要稍高于母材硬度,这是因为晶界附近出现的碳化物起到了晶界强化作用。The welding heat-affected zone(HAZ)of C-HRA-2 nickel-based alloy under various primary peak temperatures(T_(p_(1))=1150,1250,and 1350℃)and the secondary peak temperatures(T_(p_(2))=850,950,1050,1150,1250,1350,and 1450℃)was obtained by welding thermal simulation.The effect of peak temperature(T_(p))and thermal cycling times on the evolution of simulated HAZ microstructure of C-HRA-2 alloy was investigated.The microhardness of simulated HAZs was measured.The HAZ microstructure and carbide were characterized by the optical microscope,scanning electron microscope,and transmission electron microscope.Results show that the fine M_(23)C_(6)carbides appear along the grain boundaries in the simulated HAZ with T_(p_(1))=1150℃.For HAZs with T_(p_(1))1250℃,theγmatrix bonded with M_(23)C_(6)carbides appears near the grain boundaries due to component liquefaction.When T_(p_(2))is1050-1250℃,the carbides similar to those in HAZ with T_(p_(1))=1150℃can be observed near the grain boundaries due to the difference in the solid solubility of Cr in the matrix obtained at T_(p_(1))and T_(p_(2)).In HAZ with T_(p_(2))1250℃,the melted microstructure similar to that with T_(p_(1))=1250℃can be observed near the grain boundaries.The microhardness fluctuates significantly with increasing the T_(p_(2)).The microhardness of specimen with T_(p_(2))=1250℃is slightly higher than that of the base material,because of the grain boundary strengthening effect of the carbides near the grain boundaries.

关 键 词：C-HRA-2合金 焊接热模拟 组织演变 M_(23)C_(6)碳化物 

分 类 号：TG44[金属学及工艺—焊接] TG146.15[一般工业技术—材料科学与工程]