摘要
The feasibility of applying the grain boundary character distribution(GBCD)optimization to Inconel 625 for improving the intergranular corrosion(IGC)resistance was studied.The GBCD was obtained and characterized by electron backscatter diffraction(EBSD)analysis,and its optimization was mainly attributed to annealing twins(Σ3)and twins related to boundaries formed during thermal-mechanical processing(TMP).Through TMP of 5%cold rolling and subsequent annealing at 1150℃for 5 min,the proportion of lowΣcoincidence site lattice(CSL)grain boundaries of the Inconel 625 can be enhanced to about 35.8%which mainly were ofΣ3^(n)(n=1,2,3)type.There is an increase of 24.8%compared with the solution-treated sample,and simultaneously the large-size highly-twinned grain-cluster microstructure is formed.The grain-cluster is mainly composed ofΣ3-Σ3-Σ9 orΣ3-Σ9-Σ27 triple junctions,which is mainly caused by boundary reactions during grain growth.Among them,the IGC resistance ofΣ3 grain boundaries,Σ9 grain boundaries and random grain boundaries is sequentially weakened.With the increase of the lowΣCSL grain boundary fraction,the IGC resistance of Inconel 625 improves.The essential reason is the amount ofΣ3 boundaries interrupting the random boundary network increases and the large grain-cluster arrests the penetration of IGC.
作者
MA Yuanjun
WANG Jingjie
GAO Yubi
WANG Xingmao
CHEN Jianjun
DING Yutian
马元俊;WANG Jingjie;GAO Yubi;WANG Xingmao;CHEN Jianjun;丁雨田(State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China;School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China)
基金
Funded in part by the National Key Research and Development Program of China(No.2017YFA07007003)
the National Natural Science Foundation of China(No.51661019)
the Major Projects of Science and Technology in Gansu Province(No.145RTSA004)
the Hongliu First-class Discipline Construction Plan of Lanzhou University of Technology。
