低周疲劳变形过程中Fe-33Mn-4Si合金钢的微观组织演变  

Microstructure evolution of Fe-33Mn-4Si steel during low-cycle fatigue deformation

作　　者：孙琦迪 杨蔚涛 郝庆国 关肖虎 章斌 杨旗 SUN Qidi;YANG Weitao;HAO Qingguo;GUAN Xiaohu;ZHANG Bin;YANG Qi(Shanghai Research Institute of Materials,Shanghai 200437,China;Shanghai Key Laboratory of Engineering Materials Application and Evaluation,Shanghai 200437,China;School of Metallurgical Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China;Analytical Applications Center,Shimadzu(China)Co.,Ltd.Shanghai Branch,Shanghai 200233,China)

机构地区：[1]上海材料研究所,上海200437 [2]上海市工程材料应用与评价重点实验室,上海200437 [3]西安建筑科技大学冶金工程学院,西安710055 [4]岛津企业管理(中国)有限公司分析中心,上海200233

出　　处：《材料工程》2022年第4期162-171,共10页Journal of Materials Engineering

基　　金：上海市优秀学术/技术带头人计划资助项目(18XD1420700)。

摘　　要：借助X射线衍射和电子背散射衍射,研究低周疲劳变形过程中Fe-33Mn-4Si合金钢的微观组织演变及其对力学行为的影响。结果表明:实验用钢的原始微观组织由奥氏体和热诱发ε马氏体两相组成。原始组织通过影响变形过程中ε马氏体相变来影响实验用钢的低周疲劳变形行为。在变形初期(100周次内),随循环周次增加,ε马氏体含量迅速增加并且马氏体不同变体之间频繁相互交叉作用,使实验用钢的平均峰值应力和循环加工硬化程度快速增加;随后至疲劳断裂,ε马氏体成为变形微观组织中主要组成相,ε马氏体含量和马氏体不同变体的交叉频次随循环周次的增加而增速放缓,导致平均峰值应力和循环加工硬化程度的增速也明显减缓。The microstructure evolution and mechanical behavior of an Fe-33Mn-4Si alloy steel under low-cycle fatigue deformation were investigated by using the X-ray diffraction and electron backscatter diffraction techniques.Results show that the experimental steel has an initial microstructure consisting of austenite and thermally inducedε-martensite.The initial microstructure remarkably affects the low-cycle fatigue property of the experimental steel through influencing theε-martensitic transformation during deformation.At the early stage of fatigue deformation(first 100 deformation cycles),with increasing deformation cycles,a rapid increase in the volume fraction ofε-martensite and the frequency of the intersection ofε-martensite with different variants result in a quick rise in cyclic average peak stress and work hardening degree.With the continuation of cyclic deformation up to fatigue fracture,theε-martensite becomes the dominant constituent phase in the deformation microstructure,and the volume fraction ofε-martensite and the frequency of the intersection ofε-martensite increase at an appreciably slower rate,thereafter significantly slowing the increase in cyclic average peak stress and work hardening degree.

关 键 词：Fe-Mn-Si合金钢 低周疲劳变形 微观组织演变 Ε马氏体 退火孪晶 

分 类 号：TG142.1[一般工业技术—材料科学与工程]