Phase precipitation behavior and tensile properties of as-cast Ni-based superalloy during heat treatment  

一种铸造镍基高温合金在热处理过程中的相析出行为和拉伸性能（英文）

作　　者：Shuang GAO Jie-shan HOU Yong-an GUO Lan-zhang ZHOU 高双;侯介山;郭永安;周兰章(中国科学院金属研究所,沈阳110016;中国科学院大学,北京100049)

机构地区：[1]Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China [2]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Transactions of Nonferrous Metals Society of China》2018年第9期1735-1744,共10页中国有色金属学报（英文版）

基　　金：Project(51571191)supported by the National Natural Science Foundation of China;Project(NY 20150102)supported by the National Energy Administration Program of China

摘　　要：The phase precipitation behavior and tensile properties of an as-cast Ni-based alloy,IN617B alloy,after solution heat treatment and long-term aging treatment were investigated.Ti(C,N),M6C and M23C6 are the primary precipitates in as-cast microstructure.After solution heat treatment,most of carbides dissolve into the matrix except a few fine Ti(C,N)within grains.During long-term aging at 700°C,the phase precipitation behaviors of the alloy are characterized as follows:(1)M23C6 carbides at grain boundaries(GBs)transform from film-like shape to cellular shape and gradually coarsen due to the decrease of the surface energy and element aggregation to GBs;(2)M23C6 carbides within grains have a bar-like morphology with a preferential growth direction[110]and have a cube-on-cube coherent orientation relationship with the matrixγ;(3)γ?particles inhibit the coarsening of M23C6 within grains by constraining the diffusion of formation elements.Furthermore,the tensile strength of the alloy obviously increases,but the ductility significantly decreases after the aging for 5000 h.The alloy has a relatively stable microstructure which guarantees the excellent tensile properties during long-term aging.研究一种铸造镍基合金(IN617B合金)在固溶处理和长期时效处理过程中的相析出行为和拉伸性能。在铸态的组织中,Ti(C,N)、M6C和M23C6为主要析出相,而经过固溶处理后,除少量Ti(C,N)残余外,绝大部分碳化物固溶到基体中。在700°C长期时效过程中,合金中相的析出行为主要包括3个方面:(1)晶界处M23C6碳化物的形貌由膜状转变成颗粒状,同时由于界面能的降低和元素向晶界的扩散,颗粒碳化物逐渐粗化;(2)晶内棒状M23C6碳化物具有择优生长方向[110],并与基体γ之间存在共格关系;(3)γ?颗粒可以通过限制碳化物形成元素的扩散来阻碍晶内M23C6碳化物粗化。在时效5000 h后,合金的抗拉强度明显增加,而合金的塑性明显下降。该合金具有稳定的显微组织,从而保证其在长期时效过程中具有优异的拉伸性能。

关 键 词：Ni-based superalloy phase precipitation CARBIDE γ'phase tensile properties 

分 类 号：TG132.3[一般工业技术—材料科学与工程] TG166.7[金属学及工艺—合金]