中锰 TRIP 钢棘轮行为的晶粒尺寸依赖性相场研究  

A Phase-field Study on the Grain Size Dependence of the Medium-Mn TRIP Steel Ratcheting Behavior

作　　者：杨云俊 畅舒心 张娟[1,2] YANG Yunjun;CHANG Shuxin;ZHANG Juan(School of Mechanics and Aerospace Engineering,Southwest Jiaotong University,Chengdu 611756,China;Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province,Southwest Jiaotong University,Chengdu 611756,China)

机构地区：[1]西南交通大学力学与航空航天学院,成都611756 [2]西南交通大学应用力学与结构安全四川省重点实验室,成都611756

出　　处：《四川轻化工大学学报(自然科学版)》2025年第1期1-10,共10页Journal of Sichuan University of Science & Engineering(Natural Science Edition)

基　　金：国家自然科学基金项目(12272325)。

摘　　要：基于Ginzburg-Landau理论和晶体塑性理论,建立了一个可以合理反映晶粒尺寸依赖性的二维多晶弹塑性相场模型,采用相场与有限元相结合的方法模拟研究了晶粒尺寸对中锰相变诱发塑性(TRIP)钢棘轮行为的影响。研究表明,随着晶粒尺寸的减小,材料抵抗塑性变形的能力和奥氏体的稳定性逐渐提高,中锰TRIP钢的循环稳定性增强;多晶系统的TRIP效应随晶粒尺寸地减小逐渐减弱,棘轮应变率和相变生成的马氏体含量均逐渐降低,当晶粒尺寸从1.0μm减小至0.2μm,循环结束时棘轮应变和马氏体含量分别减少了0.69%和11.1%。中锰TRIP钢棘轮行为的晶粒尺寸依赖性可解释为:随着晶粒尺寸的减小,TRIP钢中各相的位错滑移抗力和晶界对位错滑移的阻碍增大,由位错引发的塑性变形减小;同时,奥氏体的机械稳定性随晶粒尺寸的减小而增加,多晶系统中的马氏体相变和相变诱发塑性应变减少。因此循环变形过程中塑性变形的产生和累积受到抑制,导致中锰TRIP钢的棘轮效应减弱。Based on the Ginzburg-Landau and crystalline plasticity theory,a two-dimensional polycrystalline elastoplastic phase-field model has been established,which can reasonably reflect the grain size dependence.The effect of grain size on ratcheting behavior of medium-Mn TRIP steel is studied by combining the phase-field with finite element method.The simulated results show that the resistance of the material to plastic deformation and the stability of austenite gradually increases with the decrease of grain size,and the cyclic stability of medium-Mn TRIP steel is enhanced.With the decrease of grain size,the TRIP effect in polycrystalline systems gradually weakens,resulting in a decrease in both the ratcheting strain rate and the content of martensite generated from phase transformation.When the grain size decreases from 1.0μm to 0.2μm,the ratcheting strain and martensite content decrease by 0.69%and 11.1%,respectively,at the end of the cycle.The grain-size dependence of ratcheting behavior in medium-Mn TRIP steels can be elucidated as follows:as the grain size diminishes,the resistance to dislocation slip of the phases and the hindrance of dislocation movement by grain boundaries in TRIP steels increase,leading to the reduction in plastic deformation induced by dislocations.Simultaneously,the mechanical stability of austenite increases with the decrease of grain size,causing a decrease in martensitic transformation and phase-transformation-induced plastic strain within the polycrystalline system.Consequently,the initiation and accumulation of plastic deformation during cyclic loading are restrained,resulting in a diminished ratcheting effect in medium-Mn TRIP steels.

关 键 词：中锰钢 晶粒尺寸 棘轮行为 马氏体相变 相场法 

分 类 号：O341[理学—固体力学]