临界淬火态热轧中锰钢单轴拉伸过程中的塑性失稳行为  

Plasticity instability behavior of hot rolled medium-Mn steel after inter-critical quenching during uniaxial tension

作　　者：刘俊杰 黄兴民[1,2] 姚鑫 赵君文[1] 张娟[3] 余代尧 毛沛宁 LIU Junjie;HUANG Xingmin;YAO Xin;ZHAO Junwen;ZHANG Juan;YU Daiyao;MAO Peining(School of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 610031,China;Key Laboratory of Advanced Technologies of Materials of Ministry of Education,Southwest Jiaotong University,Chengdu 610031,China;School of Mechanics and Aerospace Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学材料科学与工程学院,成都610031 [2]西南交通大学材料先进技术教育部重点实验室,成都610031 [3]西南交通大学力学与航空航天学院,成都610031

出　　处：《材料工程》2024年第12期134-142,共9页Journal of Materials Engineering

基　　金：四川省科技计划资助项目(2020YFH0102);国家自然科学基金项目(12272325)。

摘　　要：结合数字图像相关法(digital image correlation,DIC)、红外热成像(infrared thermal imaging,IRT)、电子背散射衍射(electron backscatter diffraction,EBSD)和显微硬度分布,重点分析临界淬火态中锰钢在单轴拉伸过程中的塑性失稳行为。结果表明:实验钢在单轴拉伸过程中应变诱导马氏体转变主要发生在拉伸变形前期,存在明显的PLC(Portevin-Le Chatelier)带形成与传播,伴随着热量波动,经历了从A型到B型带再到A型PLC带的转变;PLC带的形成原因是增殖位错与间隙溶质原子的相互作用,即动态应变时效(dynamic strain aging,DSA),前期位错会优先向低密度位错区域运动即沿轴向单向传播(A型PLC带),中期位错的增殖和开始交互作用的影响致使形成跳跃性(B型)PLC带,后期位错密度的增大和交互作用的增强,再次致使A型PLC带的形成。Combined with digital image correlation(DIC),infrared thermal imaging(IRT),electron backscatter diffraction(EBSD),and microhardness distribution,the plastic instability behavior of medium-Mn steel processed by inter-critical quenching during uniaxial tension was analyzed.The results show that the strain-induced martensite transformation of experimental steel mainly occurs in the early stage of uniaxial tension.The Portevin-Le Chatelier(PLC)bands are obviously formed and propagated during this process,accompanied by thermal fluctuations.Moreover,the type of the PLC bands has transitioned from type A to type B and then to type A.The PLC bands are formed by the interaction between dislocation multiplication and interstitial solute atoms,i.e.,dynamic strain aging(DSA).In the early stage of deformation,the dislocation will preferentially move to the low-density dislocation area,i.e.,propagate unidirectionally along the axis(the type A band).Then,in the middle stage,the dislocation multiplication and initial interaction leads to the jumping(type B)PLC band formation.Finally,dislocation density and interactions increase in the later stage of deformation,leading to the formation of the type A PLC band again.

关 键 词：热轧中锰钢 PLC带 塑性失稳 动态应变时效 应变诱导马氏体相变 

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