“γ′相+孪晶”复合结构对高温合金强度及塑性的影响  

Effect of“γ′phase and Twin”Composite Structure on Strength and Plasticity of Superalloy

作　　者：丁雨田[1,2] 张霞[1,2] 高钰璧 陈建军 张宝兵 马元俊 Ding Yutian;Zhang Xia;Gao Yubi;Chen Jianjun;Zhang Baobing;Ma Yuanjun(State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China;School of Material Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,甘肃兰州730050 [2]兰州理工大学材料科学与工程学院,甘肃兰州730050

出　　处：《稀有金属材料与工程》2022年第10期3732-3742,共11页Rare Metal Materials and Engineering

基　　金：国家重点研发计划(2017YFA0700703)。

摘　　要：本研究通过调控低合金化、低层错能的Ni-Cr-Co基变形高温合金的“γ′相+孪晶”复合结构,分析了孪晶界对晶粒细化和强度提高的贡献以及复合结构对合金强塑性的影响。结果表明,合金在1090℃保温1 h的固溶处理后,锻态组织中粗大块状γ′相基本溶解,且此时组织中的孪晶含量高达51.65%。固溶态合金延伸率(43.9%)相比于锻态(26.8%)提升了63.81%,屈服强度为693 MPa,其中孪晶强化S_(tb)=66.98 MPa,其贡献度基本和细晶强化的程度(S_(gb)=77.4 MPa)持平。将固溶态合金经700℃/8 h/AC处理后的时效态合金孪晶含量为34.41%,同时组织引入大量沉淀强化相γ′相,构成“γ′相+孪晶”复合结构,此时时效态合金硬度(HV)、抗拉强度、屈服强度与延伸率(3969.0 MPa,1042 MPa,864 MPa,44.76%)相较于固溶态(3179.1 MPa,879 MPa,693 MPa,43.9%)均得到进一步提高,其中S_(tb)=107.94 MPa。低合金化、低层错能的高温合金中的“γ′相+孪晶”复合结构实现了一定的强塑性匹配。In this study,different treatments were used to adjust the“γ′phase+twin”structure of a new Ni-Cr-Co based wrought superalloy,with low alloying and low stacking fault energy.The contribution of twin boundary to grain refinement,strength improvement and the effect of the“γ′phase+twin”structure on the mechanical properties of the alloy were analyzed.The results show that after solution treatment at 1090℃for 1 h,theγ′precipitates in the microstructure of the forged alloy are basically dissolved,and the content of twins in the structure is as high as 51.65%.The elongation(43.9%)of the solid solution alloy is 63.81%higher than that of the forged alloy(26.8%),and the yield strength is 693 MPa.Twin strengthening Stb=66.98 MPa,and its contribution is basically the same as that of fine grain strengthening(Sgb=77.4 MPa).The content of twins of the aged alloy treated by 700℃/8 h/AC is 34.41%.At the same time,a large amount ofγ′phase,which is precipitation strengthening phase,is introduced into the structure to form the“γ′phase+twin”composite structure.The hardness(HV),tensile strength,yield strength and elongation of the aged alloy(3969.0 MPa,1042 MPa,864 MPa,44.76%)are further improved compared with those in the solid solution state(3179.1 MPa,879 MPa,693 MPa,43.9%),and Stb=107.94 MPa.The“γ′phase+twin”composite structure in superalloys with low alloying and low stacking fault energy achieves a certain strength-plastic matching.

关 键 词：新型Ni-Cr-Co基变形高温合金 “γ′相+孪晶”复合结构 微观组织 孪晶强化 力学性能 

分 类 号：TG146.15[一般工业技术—材料科学与工程]