冷拉伸预变形及热处理对Hastelloy C-276合金晶界特征的影响  

Influence of cold tensile pre-deformation and heat treatment on grain boundary characteristics of Hastelloy C-276 alloy

作　　者：刘翊安 张晓宇 孙欢迎 庞国星 吴伟 Liu Yian;Zhang Xiaoyu;Sun Huanying;Pang Guoxing;Wu Wei(School of Materials Engineering,North China Institute of Aerospace Engineering,Langfang Hebei 065000,China)

机构地区：[1]北华航天工业学院材料工程学院,河北廊坊065000

出　　处：《金属热处理》2021年第7期13-18,共6页Heat Treatment of Metals

基　　金：河北省科技厅基金(18211043);北华航天工业学院科研基金重点项目(ZD-2020-02);北华航天工业学院青年基金(KY-2018-27)。

摘　　要：对Hastelloy C-276合金分别进行2%、6%、14%、22%、30%和54%冷拉伸预形变后经1100℃×15 min等温退火并水冷,采用EBSD技术分析变形量对其合金晶界特征分布和晶粒尺寸的影响。结果表明,随着变形量的增加,总的特殊晶界比例呈先下降后上升最后下降的趋势。当变形量为14%时,总的特殊晶界比例出现峰值点,达到了64.8%,同时Σ1晶界比例出现拐点,呈下降趋势,变形储存能得以释放,有利于特殊晶界的产生。此时,晶粒组织处于再结晶初始阶段。但大变形条件下的退火并不利于特殊晶界比例的提高。随着晶粒尺寸的增加,退火孪晶密度降低,选择适当的晶粒尺寸有利于晶界特征分布优化。Hastelloy C-276 alloy was cold tensile deformed for 2%,6%,14%,22%,30%and 54%,respectively,then isothermally annealed at 1100℃for 15 min and water cooled.Effects of deformation on the grain boundary characteristic distribution and on the grain size of the alloy were analyzed by EBSD technology.The results show that the total special grain boundary ratio shows a trend of decreasing first,then increasing and finally decreasing.When the deformation is up to 14%,the total proportion of special boundary reaches its peak point as to 64.8%;the Σ1 grain boundary proportion appears inflection point then tends to decrease,and the deformation storage energy can be released so the special grain boundary formation is promoted.At this time,the grain structure is in the initial stage of recrystallization.However,annealing under large deformation conditions is not conducive to increase the proportion of special grain boundaries.With the increase of grain size,the density of annealing twin decreases,so to optimize the grain size is conducive to the optimization of grain boundary character distribution.

关 键 词：冷变形 热处理 退火孪晶 晶界特征分布 孪晶密度 

分 类 号：TG111[金属学及工艺—物理冶金]