两步退火热处理对Hastelloy C-276合金晶界特征分布的影响  

Grain Boundary Character Distributions of Hastelloy C-276 Alloy with Two-Step Annealing Heat-Treatment

作　　者：张晓宇[1,2] 李德富[1] 郭胜利[1] 赵宪明[2] Zhang Xiaoyu;Li Defu;Guo Shengli;Zhao Xianming(Processing Division, Beijing General Research Institute for Nonferrous Metals, Beijing 100088, China;State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, China)

机构地区：[1]北京有色金属研究总院加工事业部,北京100088 [2]东北大学轧制技术及连轧自动化国家重点实验室,辽宁沈阳110819

出　　处：《稀有金属》2018年第6期608-613,共6页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(50834008)资助

摘　　要：Hastelloy C-276合金经小变形量5%冷轧变形后,分别采用高温一次退火和二次退火两种方式进行热处理,其晶界特征分布采用电子背散射衍射技术进行表征。结果表明,经二次退火热处理后的试样相对于一次退火热处理试样具有更高比例Σ3晶界的产生,通过晶界间相互作用,进而形成较高比例Σ9和Σ27晶界,使得总的Σ3~n晶界比例达到了78.8%。并且这些特殊晶界有效地阻断大角度晶界的连通性,进一步形成大尺寸晶粒团簇组织,使二次退火试样晶界特征分布得到优化。对比分析两种不同热处理制度下的Σ3和Σ9晶界面分布,可知Σ3晶界面分布主要集中在以{111}极点为中心的扩展区域内,Σ9晶界面主要分布在[110]晶带范围内。这两种晶界面由于热处理制度不同,其分布范围也有所不同。由于二次退火产生非共格孪晶Σ3晶界的较多,使得二次退火试样中的Σ3晶界面分布范围大于一次退火,并导致试样中更多Σ9晶界面偏离了〈110〉取向。Hastelloy C-276 samples were cold-rolled with thickness reduction of 5% and employed by one-step annealing and twostep annealing processing to heat-treatment,and their grain boundary character distributions（GBCDs） were characterized by electron back scatter diffraction（EBSD） techniques. The results showed that more Σ3 boundaries were produced in two-step annealing heattreatment sample compared to one-step one. Meanwhile,through the interactions of special boundaries,higher proportions of Σ9 andΣ27 boundaries were formed; the fraction of total Σ3~n boundaries was up to 78. 8%. Those special boundaries contributed to disrupt the connectivity of high angle boundary network and the larger clusters were formed. The grain boundary character distributions of two-step annealing heat-treatment sample were optimized. According to the analysis of Σ3 and Σ9 grain boundary plane distributions by different annealing processes,the relative areas of Σ3 boundary planes were centered on {111} planes and the distributions of grain boundary density planes for Σ9 boundary were centered on [110] zone. Due to the different annealing processes,the relative areas for Σ3 andΣ9 boundaries in both samples were different. The relative areas of Σ3 grain boundary plane distribution in two-step annealing heattreatment sample were larger than those of one-step one. It was due to more incoherent Σ3 boundaries productions,which resulted in more grain boundary plane with orientations of Σ9 were deviated from the reference 〈 110 〉 misorientation.

关 键 词：二次退火热处理 HASTELLOY C-276合金 晶界特征分布 

分 类 号：TG111[金属学及工艺—物理冶金]