电子束焊接钼铼合金组织和性能研究  

Microstructures and Properties Research of Electron Beam Welded Joints of Molybdenum-Rhenium Alloys

作　　者：熊宁[1] 张莹莹 邱玺 冯波[3] 陈福鸽[1] 王广达[1] Xiong Ning;Zhang Yingying;Qiu Xi;Feng Bo;Chen Fuge;Wang Guangda(Advanced Technology&Materials Co.,Ltd,Beijing 100081,China;Nuclear Power Institute of China,Chengdu 610213,China;China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]安泰科技股份有限公司,北京100081 [2]中国核动力研究设计院,四川成都610213 [3]中国原子能科学研究院,北京102413

出　　处：《稀有金属》2022年第9期1172-1180,共9页Chinese Journal of Rare Metals

基　　金：天津市科技计划项目(20YDLZGX00020)资助。

摘　　要：钼铼(Mo-Re)合金是空间核电源中反应堆芯结构最佳候选材料之一。为了研究不同铼含量的钼铼合金的组织和焊接性能,以Mo5Re,Mo14Re和Mo42Re(%,质量分数)3种合金管材为原料,采用电子束焊接方法进行焊接。利用光学显微镜(OM)、ZQJ-3200氦质谱检漏仪、扫描电镜(SEM)、X射线衍射(XRD)、维氏硬度仪和拉伸设备等检测手段对焊接接头的性能进行研究。采用Image-Pro Plus分析软件统计焊缝处的气孔率,并深入分析了焊接熔池区域处气孔的产生机制。研究结果表明:采用电子束焊接钼铼合金管材的焊缝呈“钉子”形状。与母材相比,3种钼铼合金熔池区域晶粒尺寸明显长大,熔池边缘及内部存在少数气孔,Image-Pro Plus分析软件统计出Mo5Re,Mo14Re和Mo42Re合金焊缝处气孔率分别为0.8%,1.2%和0.3%。Mo5Re焊接接头处存在Mo相,Mo14Re焊接接头处存在Mo相和Mo_(3)Re_(2)相,Mo42Re焊接接头处存在Mo_(3)Re_(2)相。3种钼铼合金焊接接头焊缝区和热影响区处维氏硬度值均低于母材,Mo5Re,Mo14Re和Mo42Re合金焊缝区维氏硬度比其各自母材分别低22.7%,28.2%和14.8%。Mo42Re合金母材区维氏硬度为HV 360.6,焊缝中心区为HV 307.1。拉伸测试结果表明,Mo5Re合金焊缝处室温抗拉强度为221 MPa,1500 K时高温抗拉强度仅为85 MPa。Mo14Re合金焊缝处室温和高温抗拉强度高于Mo5Re合金。Mo42Re合金焊缝处室温抗拉强度和高温抗拉强度分别为母材的49.2%和45.8%。3种钼铼合金材料焊接性能相比,Mo42Re合金焊接接头性能最佳。Molybdenum-rhenium(Mo-Re)alloys had high melting point and better excellent radiation resistance,high tensile strength,good ductility and thermal shock resistance.Compared with pure metal molybdenum,Mo-Re alloys had become promising high-temperature refractory materials,which had been widely used for aerospace,heating equipment,nuclear industry and many oth-er fields.With the continuous development of applications in cutting-edge fields such as nuclear power,welding methods of Mo-Re al-loys had attracted the close attention of many researchers.Currently,welding methods of refractory metals mainly included tungsten ar-gon arc welding(TIG),laser welding(LW),resistance welding(RSW),friction welding(FW)and electron beam welding(EBW).EBW had high energy density and strong penetration capability,which could obtain high-quality joints with narrow weld metal(WM)and heat-affected zone(HAZ),and it was easy to achieve deep penetration welding of metal materials.EBW process was in a vacuum state,and was less contaminated by oxygen,nitrogen and other gases.In addition,EBW process was easy to precisely control,with good repeatability and stability,and easily realized automation.So EBW technology was widely used in the field of refractory metals welding and could realize to weld of precision structural parts,for example,the large thickness of molybdenum and molybdenum alloy parts.Therefore,EBW had become the most widely used method for high melting point Mo-Re alloy welding because of its advantages.The present work aimed to investigate the microstructures and properties of Mo-Re alloys with different rhenium contents.These speci-mens to be welded were tube-end plug construction with socket structure.The outer diameter of tube was 20 mm,and the wall thinness was 1.3 mm and the middle layer was not added.Mo-Re alloy specimens,Mo5Re,Mo14Re and Mo42Re(%,mass fraction),were used as raw materials and welded for EBW.EBW welding parameters were:accelerating voltage of 60~65 kV,beam current of 12~14mA,welding speed of 5~6 mm·s^(-1),wo

关 键 词：钼铼(Mo-Re)合金 电子束焊接(EBW) 焊接接头 

分 类 号：TG456.3[金属学及工艺—焊接]