摘要
在不改变GH3625合金化学成分的前提下,通过晶界工程(GBE)优化和调控合金组织,从而改善合金的高温组织稳定性以及使用可靠性。采用电子背散射衍射(EBSD)和取向成像显微技术(OIM)研究了形变热处理对GH3625合金晶界特征分布(GBCD)的影响。结果表明,GH3625合金晶界特征分布的优化主要是通过再结晶过程中形成的Σ3n晶界来实现的,同时主要受冷变形量和退火条件的影响;GH3625合金中低ΣCSL晶界比例随着冷变形量的增加而减小,随着退火温度的升高而增加,当合金在ε=35%,退火温度为1120℃保温15 min时,低ΣCSL晶界比例可提高到63.16%以上(Palumbo-Aust标准);此外,GH3625合金中出现了大尺寸的晶粒团簇,在晶粒团簇内的晶粒之间具有Σ3n的取向关系;晶粒团簇尺寸和内含Σ3n晶界的数量随着冷变形量的增加而减小,随着退火温度的升高而增加。
With this prerequisite that the chemical composition of GH3625 alloy will not be changed,the high temperature microstructure stability and service performance reliability of alloys are improved by optimizing grain boundary engineering(GBE)and controlling the microstructure of alloys.The effect of thermal-mechanical processing on the grain boundary character distribution(GBCD)of GH3625 superalloy was investigated by the electron backscattered diffraction(EBSD)technique and orientation image microcopy(OIM).The results show that the optimization of the grain boundary character distribution(GBCD)of GH3625 superalloy is mainly achieved byΣ3n grain boundaries formed during the recrystallization process,and is mainly affected by the cold deformation and annealing process.The length fraction of lowΣCSL grain boundaries in GH3625 superalloy decreases with the increase of cold deformation,while increases with the increase of annealing temperature.Meanwhile,the length fraction of lowΣCSL(coincident site lattice,Σ≤29 by Palunbo-Aust criterion)grain boundaries increases to more than 63.16%after 35%cold deformed and subsequent annealing at 1120℃ for 15 min.In addition,large sized grain-clusters appear in GH3625 superalloy,and boundaries haveΣ3n misorientations inside the grains-cluster.The size of the grain-clusters and the amount ofΣ3n grain boundaries inside the grains-cluster decrease with the increase of cold deformation,but increase with the increase of annealing temperature.
作者
高钰璧
丁雨田
陈建军
许佳玉
马元俊
王兴茂
Gao Yubi;Ding Yutian;Chen Jianjun;Xu Jiayu;Ma Yuanjun;Wang Xingmao(State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2019年第11期3585-3592,共8页
Rare Metal Materials and Engineering
基金
国家重点研发计划项目(2017YFA0700703)
国家自然科学基金项目(51661019)
甘肃省重大科技专项项目(145RTSA004)
关键词
GH3625合金
形变热处理
晶界特征分布
晶界工程
低ΣCSL晶界
GH3625 alloy
thermo-mechanical processing
grain boundary character distribution
grain boundary engineering
lowΣCSL grain boundary
