形变及热处理对690合金晶界特征分布的影响

Effect of Deformation and Heat-Treatments on the Grain Boundary Character Distribution for 690 Alloy

应用电子背散射衍射(EBSD)和取向成像显微技术(OIM)研究了材料初始状态、冷轧压下量和1100℃退火对690合金晶界特征分布(GBCD)的影响。低层错能面心立方金属镍基690合金,冷轧5%后在1100℃退火5min可使低ΣCSL(coincidence site lattice,Σ≤29)晶界比例提高到70%以上(Palumbo-Aust标准),同时形成大尺寸的晶粒团簇。低ΣCSL晶界比例和这种晶粒团簇的尺寸随冷轧压下量的增加而下降。初始状态的固溶或时效对690合金在1100℃再结晶退火后的晶界特征分布无明显影响。

Effects of initial state, cold rolling reduction ratio, and annealing at 1100 ℃ on the grain boundary character distribution （GBCD） in 690 alloy have been investigated by electron backscatter diffraction （EBSD） and orientation imaging microscopy （OIM）. It can increase the grain boundary ratio of low ∑CSL （coincidence site lattice, ∑≤29 by Palumbo-Aust criterion） to be more than 70%, and simultaneously forms the grains-cluster of large size by cold rolling of 5% and subsequent annealing high at 1100 ℃. The proportion of low ∑CSL grain boundaries and the size of grains-cluster decrease with the increase of strain. The initial state, i.e. solution annealed or aged, does not affect the GBCD obviously.