Z2CND18.12N奥氏体不锈钢低周疲劳损伤的EBSD分析  

EBSD analysis of low-cycle fatigue damage in Z2CND18.12N austenitic stainless steel

作　　者：车枫 孟亦圆 林莉[1] 罗忠兵[1] CHE Feng;MENG Yiyuan;LIN Li;LUO Zhongbing(NDT&E Laboratory,Dalian University of Technology,Dalian 116024,Liaoning,China)

机构地区：[1]大连理工大学无损检测研究所,辽宁大连116024

出　　处：《材料工程》2024年第6期177-183,共7页Journal of Materials Engineering

基　　金：国家自然科学基金项目(51775087);辽宁省“兴辽英才计划”项目(XLYC1902082)。

摘　　要：针对核电管道用Z2CND18.12N奥氏体不锈钢的低周疲劳损伤,研究电子背散射衍射(electron backscattered diffraction,EBSD)采集与后处理参数对局域取向差(local misorientation,ML)的影响,基于优选参数探讨特征取向晶粒的损伤规律。结果表明:测试步长、取向差平均范围(filter)及像素合并参数(binning)均影响ML测试结果,综合考虑晶粒尺寸、测试精度和效率等因素,优选确定binning 2×2,filter 11×11,测试步长为2μm或5μm。选取损伤程度不同的两个区域,〈111〉取向晶粒ΔM_(L)的峰值和平均值变化均高于〈101〉和〈001〉取向,〈101〉取向ΔM_(L)数值最小;同时,ML在小晶粒特别是晶界及交汇处数值较大。结合晶粒尺寸、晶界对变形分布的不均匀性进行了讨论。结果证实ML可以有效评价Z2CND18.12N钢的变形损伤,为发展基于多物理参量的材料以及结构损伤评价技术提供了参考和借鉴。Aimed at low-cycle fatigue damage of Z2CND18.12N austenitic stainless steel for nuclear power pipelines,the influences of the acquisition and post-processing parameters on the local misorientation(ML)were studied by electron backscattered diffraction(EBSD)technique.The damage evolution of grains with typical orientations was discussed based on the parameters after optimization.The results show that the step size,filter and binning all affect the value of ML.Taking into account factors such as grain size,testing accuracy,and efficiency,the optimal selection is to determine binning 2×2,filter 11×11,and testing step size of 2μm or 5μm,respectively.Two damage regions with different levels are characterized.The peak and average values ofΔM_(L) in〈111〉orientation are higher than those in〈101〉and〈001〉orientations,and the values ofΔM_(L) in〈101〉orientation are the smallest.Large ML is observed in small grains,especially in the grain boundaries and intersections.Meanwhile,non-uniformity of deformation distribution was discussed in according to the effects of grain size and grain boundary.It is confirmed that ML can effectively evaluate the deformation damage of Z2CND18.12N steel,which is valuable for the development of material and structural damage evaluation technology based on multi-physical parameters.

关 键 词：奥氏体不锈钢 疲劳 电子背散射衍射 晶体取向 局域取向差 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TG115[金属学及工艺—金属材料] TB31[金属学及工艺—金属学]