文献类型：期刊文献

中文题名：双相不锈钢循环微变形行为的原位试验研究

英文题名：In-Situ Experimental Study on Cyclic MicroDeformation Behavior of Duplex Stainless Steel

作者：张涛[1];金鑫[2];陈蓉[1];朱明亮[1];郭素娟[1]

机构：[1]华东理工大学承压系统与安全教育部重点试验室,上海200237;[2]中广核研究院有限公司,广东深圳518028

年份：2022

卷号：43

期号：3

起止页码：502

中文期刊名：力学季刊

外文期刊名：Chinese Quarterly of Mechanics

收录：CSTPCD;;北大核心:【北大核心2020】；CSCD:【CSCD_E2021_2022】；

基金：国家自然科学基金(11872181,11302079);上海市浦江人才计划(2019PJD009)。

语种：中文

中文关键词：双相不锈钢;数字图像相关法;微变形;微棘轮变形;两相

外文关键词：duplex stainless steel;DIC;micro-deformation;micro-ratcheting deformation;two-phase

摘要：对双相不锈钢开展拉伸和应力循环控制下的原位试验研究,选择特征区域对其局部微变形行为的产生、分布和演化进行了研究和讨论.结果表明:双相不锈钢在较低的载荷作用下内部出现明显的应变梯度,随着拉伸载荷或循环周次的增长,其局部微应变不断增加,最大应变在奥氏体相、小晶粒、狭窄晶粒和不平整的晶界区不断汇集,同一时刻的局部最大微应变远大于宏观应变;循环载荷作用下双相不锈钢在微观尺度产生了局部微棘轮变形效应,微棘轮应变随着循环周次的增加不断累积,其增长速度逐渐降低并趋于饱和;随着循环周次的增加,最大微棘轮变形区逐渐扩展、联通形成大塑性变形带,晶粒走向呈45°方向时,变形带贯穿两相向垂直加载方向发展,而晶粒呈树根状走向时,由于受到两相交互和铁素体的阻碍作用,微棘轮变形带主要集中在奥氏体中沿着奥氏体晶粒走向发展.
In-situ tensile and stress cycling scanning electron microscope-digital image correlation(SEM-DIC)experiments were carried out on duplex stainless steel.The generation,distribution and evolution process of local micro-deformation behavior were discussed based on characteristic regions.It is shown that apparent strain gradient appeared inside the duplex stainless steel even at low loading levels.As the tensile loading level or the cycle times increase,the local microstrain increases,and the maximum strain continuously accumulates at the austenite grain,the small grain,the narrow grain and the irregular grain boundaries.At the same time,the local maximum microstrain was greater than the macroscopic strain.Under the cyclic loading,the local micro-ratcheting deformation mechanism occured in the duplex stainless steel.The ratcheting deformation accumulated with the increase of cycles whose growth rate decreased gradually until saturation.With the increase of cycles,the largest micro-ratcheting deformation zone gradually expanded and connected to form a large plastic zone.When the grains were oriented along 45°direction,the deformation bands were developed across the two phases perpendicular to the loading direction.When the grains took on a tree-root appearance,the micro-ratcheting deformation bands were mainly focused in the austenite and developed along the direction of the austenite grain boundary due to the interaction between the two phases and the hindrance of the ferrite.