冷轧退火后铁素体不锈钢的晶界面分布

来源期刊：金属学报2010年第4期

论文作者：方晓英 王卫国 Rohrer G S 周邦新

文章页码：404 - 410

关键词：铁素体不锈钢； 晶界面分布； 晶界取向； EBSD

Key words：ferritic stainless steel； grain boundary plane distribution； grain boundary misorientation； EBSD

摘    要：采用EBSD技术测定了冷轧退火铁素体不锈钢样品单一截面(轧面)的取向成像显微图(OIM),采用直线拟合法重构出晶界迹线,利用五参数法对晶界面{hkl}的分布进行了统计分析.结果表明,经85%冷轧变形的样品再经780℃退火后,合金虽然不存在明显的晶粒取向织构,也不存在以特定轴角对为特征的晶界择优分布,但其晶界面{hkl}的分布却具有一定的择优特性,而且在不同退火阶段,随着平均晶粒尺寸由小变大,择优分布的晶界面随之改变.当平均晶粒尺寸为9μm时,择优分布的晶界面为{100}晶面,其分布密度超过平均值12%左右;随着晶粒的长大,当平均晶粒尺寸达到15μm时,择优分布的晶界面以{111}为主,其次为{100}和{112}晶面,其最高分布密度超过平均值10%左右.对于特定取向差晶界,这种晶界面的择优分布特性明显增强.分析认为,退火过程中某些低能晶界由于迁移速率低而被保留下来是晶界面分布存在择优性的重要原因.

Abstract: The grain boundary plane distribution in the cold-rolled and annealed ferritic stainless steel has been analyzed statistically by a five-parameter method based on the mis-orientations of adjacent grains and the orientations of grain boundary traces determined by electron backscatter diffraction (EBSD) attached to a field emission scanning electron microscope (FE-SEM).The results show that no preferred texture occurrs either in grain orientations or grain boundary mis orientations characterized by axis-angle pairs in the specimens which were cold rolled by 85% reduction in thickness and subsequently annealed at 780℃.However,there are developed textures for the orientations of grain boundary planes.And also,the preferred planes vary with averaged grain size levels.At the level of 9μm,grain boundary planes favor the {100} orientation,with their density distribution 12% higher than a random distribution;Whereas at the level of 15μm,{111} planes are preferred and {100} and {112} planes are sub-preferred,with the density distribution on {111} about 10% higher than a random distribution.Moreover,the anisotropy of grain boundary plane distributions is larger at specific mis-orientations.The discussion points out the preferred grain boundary planes might possess lower energies and tend to being preserved due to their lower growth rates during annealing.