固溶和时效处理对新型低钴高温合金组织和高温力学性能的影响  

Effect of solution and aging treatment on microstructure and high temperature mechanical properties of a new low-cobalt superalloy

作　　者：王珏[1,2] 顾晔林 胡亮 王俊杰 王伟娟 WANG Jue;GU Ye-lin;HU Liang;WANG Jun-jie;WANG Wei-juan(School of Materials Science and Engineering,Nanjing Institute of Technology,Nanjing 211167,China;Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology,Nanjing 211167,China)

机构地区：[1]南京工程学院材料科学与工程学院,江苏南京211167 [2]江苏省先进结构材料与应用技术重点实验室,江苏南京211167

出　　处：《材料热处理学报》2024年第8期118-126,共9页Transactions of Materials and Heat Treatment

基　　金：江苏省产业前瞻与关键核心技术竞争项目(BE2019027);江苏省先进结构材料与应用技术重点试验室开放基金(ASMA202106);南京工程学院大学生科技创新基金项目(TB202302065)。

摘　　要：采用真空感应熔炼方法制备了一种新型低钴高温合金,利用扫描电镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)和电子万能试验机等研究了固溶处理和高温时效处理对合金组织和高温拉伸性能的影响。结果表明:低钴高温合金铸态组织中包含(γ+γ′)共晶组织、富W/Ta的MC_((1))碳化物和富Ta/Hf的MC_((2))碳化物,以及大小两种尺寸的γ′相,Hf、Ta元素明显偏析于枝晶间。随着固溶温度升高和时间延长,(γ+γ′)共晶组织逐渐回溶、元素偏析消除,小尺寸γ′相的含量升高。固溶过程中MC_((1))碳化物逐渐溶解,边缘转变为富W的M6C型碳化物,MC_((2))中Hf含量升高而Ta含量降低。经1295℃固溶处理6 h及1090℃高温时效8 h后,合金中的共晶组织的体积分数降至1.3%,具有较好的高温拉伸性能。A new type of low-cobalt superalloy was prepared by vacuum induction melting method.The effect of solution treatment and high-temperature aging treatment on microstructure and high-temperature tensile properties of the alloy was studied using scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS)analysis,X-ray diffraction(XRD)and electronic universal testing machine.The results show that the as-cast microstructure of the low-cobalt superalloy contains(γ+γ′)eutectic structure,MC_((1))carbides rich in W/Ta and MC_((2))carbides rich in Ta/Hf,as well as two different sizes ofγ′phase,Hf and Ta elements are significantly segregated between dendrites.With the increase of solution temperature and time,the(γ+γ′)eutectic structure gradually dissolves back,element segregation is eliminated,and the content of smallγ′phase increases.The MC_((1))carbides dissolve during the solution treatment and transform into W-rich M6C carbides at the edge.The Hf content in the MC_((2))carbides increases while the Ta content decreases.After solution treatment at 1295℃for 6 h and high-temperature aging at 1090℃for 8 h,the volume fraction of eutectic structure in the alloy decreases to 1.3%,and it has good high-temperature tensile properties.

关 键 词：低钴高温合金 固溶处理 共晶组织 高温拉伸 

分 类 号：TG132.3[一般工业技术—材料科学与工程]