先进高强DP980钢动态再结晶行为  

Dynamic recrystallization behavior of high strength DP980 steel

作　　者：仲维锋[1] 庄利珍 滕敦波[1] ZHONG Wei-feng;ZHUANG Li-zhen;TENG Dun-bo(College of Engineering,Yantai Nanshan University,Yantai 265713,China)

机构地区：[1]烟台南山学院工学院

出　　处：《塑性工程学报》2019年第4期171-175,共5页Journal of Plasticity Engineering

基　　金：山东省自然科学基金资助项目(ZR2016EMP05)

摘　　要：在Gleeble 3500多功能热模拟试验机上,对高强DP980钢进行了单道次压缩实验,研究了该钢在1323~1423 K和0.05~10 s-1变形条件下的热变形行为,分析了变形温度和变形速率对流变应力曲线的影响,揭示了变形软化机制,分析了在热变形过程中微观组织的演变规律,分阶段建立了热压缩变形抗力本构模型。结果表明:流变应力对变形温度和应变速率都很敏感,随变形温度的增加和变形速率的减小而减小,低应变速率下呈动态再结晶型软化机制;应变速率ε·>0.1 s-1时,呈动态回复型软化机制。同一变形温度下,低应变速率易于该钢中奥氏体再结晶的启动;同一变形速率下,变形温度越高,奥氏体再结晶现象越明显。分阶段所建立的本构模型预测值与实验值的相关系数达到0.9978,平均相对误差绝对值为2.67%,证明此模型具有较高精度。The hot compressive deformation behaviors of high strength DP980 steel were investigated at temperature range from 1323 to 1423 K and strain rate from 0.05 to 10 s-1 by single pass hot compression test on Gleeble 3500 thermo-simulation machine.The influence of deformation temperature and deformation strain rate on the flow stress curves was analyzed,the softening mechanism of the experimental steel was revealed,the microstructure evolution during the hot deformation process was investigated,and the deformation resistance consti-tutive model was established by stages.The results show that the flow stress is sensitive to deformation temperature and deformation strain rate,decreases with the increase of deformation temperature and the decrease of strain rate.The dynamic recrystallization(DRX)soften-ing mechanism is more evident at low strain rates,while dynamic recovery(DRV)softening mechanism is dominant when strain rate is higher than 0.1 s-1.At the same deformation temperature,the recrystallization is easy to trigger at low strain rate.And at the same strain rate,the deformation temperature is higher,the more obvious austenite recrystallization.The correlation coefficient between the predicted and tested valus of the established constitutive model by stages is 0.9978 and the average absolute value of relative error is 2.67%,which indicates the constitutive model has high precision.

关 键 词：高强DP钢 变形行为 本构模型 动态再结晶软化机制 

分 类 号：TG111.7[金属学及工艺—物理冶金]