Effect of grain size on the intrinsic mechanical stability of austenite in transformation-induced plasticity steels:The competition between martensite transformation and dislocation slip

作     者：D.P.Yang T.Wang Z.T.Miao P.J.Du G.D.Wang H.L.Yi D.P.Yang;T.Wang;Z.T.Miao;P.J.Du;G.D.Wang;H.L.Yi

作者机构：State Key Laboratory of Rolling and AutomationNortheastern UniversityShenyang 110819China 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2023年第162卷第31期

页      面：38-43页

核心收录：

学科分类：080503[工学-材料加工工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0802[工学-机械工程] 080201[工学-机械制造及其自动化] 

基　　金：supported by the National Natural Science Foundation(No.52101128) the National Key R&D Program(No.2018YFE0306102) the Postdoctoral Science Foundation(No.2022M710021) the Northeastern University Postdoctoral Research Fund of China(No.20220202) 

主　　题：austenite martensite transformation 

摘      要：The deformation accompanied by austenite to martensite trans-formation was first studied in Fe-Ni alloys,high-Mn steels,and austenitic stainless steels with a full austenite *** plasticity of these steels can be improved by the trans-formation during deformation and hence they were named as transformation-induced plasticity(TRIP)steels[1].Over the past few decades,a series of TRIP steels with multiphase microstructure for automotive applications were *** steels contain-ing a certain amount of austenite were called TRIP-assisted steels,such as low-alloy TRIP steels[2],carbide-free bainitic steels[3],δ-TRIP steels[4],quenching and partitioning steels[5],and medium-Mn steels[6].The mechanical property of TRIP steels is largely determined by the mechanical stability of austenite[7]which de-pends on the chemical composition[8],grain size[9],orientation[10],and morphology[11]of austenite grains,as well as the nature of neighboring phases[12].In most cases of TRIP-assisted steels,larger austenite grains transform to martensite earlier or faster than smaller austenite grains with the increase of macrostrain[13-18],indicating lower mechanical ***,larger austen-ite grains usually contain less C and Mn[13,17-19]and suffer more strain than smaller grains during deformation[20],it doesn’t mean that grain refinement increases the mechanical stability of austen-ite.