摘要
热轧淬火态中锰实验钢的初始显微组织通常由板条马氏体基体和极少量粒状奥氏体构成,存在明显的Mn偏析带。采用两步(750℃×1 h+700℃×1 h)临界退火工艺,在不显著改变残余奥氏体含量的前提下,通过分阶段控制富锰区和贫锰区的奥氏体逆转变程度,有效地促进残余奥氏体晶粒细化及机械稳定性的梯度分布。结果表明:在单轴拉伸过程中诱导了更充分和持续的应变诱发马氏体相变。通过相变/孪晶诱发塑性效应协同增韧,最终获得优异强度和韧性匹配,断后伸长率和强塑积达到85.3%和73.4 GPa·%。
Usually,the initial microstructure of hot-rolled and quenched medium-manganese experimental steel is composed of lath martensite matrix and a small amount of tiny granular austenite,also existing apparent Mn-segregation bands.Using double intercritical annealing(holding 60 min at 750℃followed by 60 min at 700℃),austenite reversion transformation in Mn-rich and Mn-lean regions are modulated by stages,which efficiently promoting the refinement of retained austenite grains and the optimization of mechanical stability distribution without apparent variation of volume fraction of retained austenite.The results show that adequate and sustained strain-induced martensite transformation is favored and boosted during uni-axial tensile deformation.Due to synergistic toughening of transformation and twinning induced plasticity effects,excellent combination of strength and ductility,such as the ultra-high total elongation of 85.3%and product of strength and plasticity(PSE)of 73.4 GPa∙%are obtained eventually.
作者
毛沛宁
黄兴民
吕超
刘俊杰
张娟
MAO Peining;HUANG Xingmin;LYU Chao;LIU Junjie;ZHANG Juan(Key Laboratory of Advanced Technologies of Materials,Ministry of Education,School of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 610031,China;Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province,School of Mechanics and Aeronautics and Astronautics,Southwest Jiaotong University,Chengdu 610031,China)
出处
《材料工程》
北大核心
2026年第3期170-180,共11页
Journal of Materials Engineering
基金
国家自然科学基金(12272325)。
关键词
两步临界退火
含铝中锰钢
Mn偏析
残余奥氏体
机械稳定性
double intercritical annealing
Al-contained medium-Mn steel
Mn segregation
retained austenite
mechanical stability
