锻态42CrMo钢高温变形过程中本构模型修正及激活能演化  

Modification of constitutive model and evolution of activation energy for forged 42CrMo steel during high temperature deformation process

作　　者：陈园园 齐会萍[1] 李永堂[1] 庞晓龙 Chen Yuanyuan;Qi Huiping;Li Yongtang;Pang Xiaolong(College of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China;College of Mechanical Engineering,Jinzhong University,Jinzhong 030600,China)

机构地区：[1]太原科技大学材料科学与工程学院,山西太原030024 [2]晋中学院机械系,山西晋中030600

出　　处：《锻压技术》2021年第11期260-269,共10页Forging & Stamping Technology

基　　金：国家自然科学基金资助项目(51875383,51575371);山西省高校科技创新项目(2020L0579)。

摘　　要：采用Gleeble-3500D热模拟试验机,对锻态42CrMo钢进行高温压缩试验,试验变形温度为1123、1223和1323 K,试验应变速率为0.01、0.1、1和5 s^(-1),采集到流动应力-应变曲线。试验结果显示,该材料的流动应力同时受到应变、应变速率及变形温度的影响。借助Arrhenius本构模型,考虑应变、应变速率和变形温度对锻态42CrMo钢不同材料参数的影响,将应变、应变速率和变形温度的影响纳入本构方程,建立考虑应变、应变速率和变形温度的锻态42CrMo钢本构模型,并对传统本构方程进行修正。通过对比试验和预测流动应力,对该模型的适用性进行了评价,得到R和ARRE值分别为0.9926和3.54%,并将该修正的本构模型的精度与前人本构模型精度进行对比,发现修正的本构模型的精度明显更高,说明考虑应变、应变速率和变形温度的本构模型能够更准确、更全面地预测该材料的流动应力。而且不同变形条件下的激活能随着变形温度的升高先降低后升高,随着应变速率的升高先升高后降低,同时激活能受到应变和应变速率耦合效应的影响。The high temperature compression experiments of forged 42 CrMo steel were conducted by thermal simulator Gleeble-3500 D at the deformation temperatures of 1123,1223 and 1323 K and the strain rates of 0.01,0.1,1 and 5 s^(-1),and the flow stress-strain curves were obtained.The experimental results show that the flow stress of material is simultaneously affected by strain,strain rate and deformation temperature.With the help of Arrhenius constitutive model,the influences of the strain,strain rate and deformation temperature on different material parameters of forged 42 CrMo steel were considered,the effects of the strain,strain rate and deformation temperature were incorporated into the constitutive equation to establish a constitutive model of forged 42 CrMo steel considering strain,strain rate and deformation temperature,and the traditional constitutive model was modified.Then,the applicability of the model was evaluated by comparative experiments and prediction of flow stress,and the values of R and ARRE are 0.9926 and 3.54%,respectively.Comparing the accuracy of the modified constitutive model with that of previous constitutive models,it is found that the accuracy of the modified constitutive model is higher obviously.It shows that the constitutive model considering strain,strain rate and deformation temperature can predict the flow stress of the material more accurately and comprehensively.Furthermore,the activation energy under different deformation conditions shows firstly decreases and then increases with the increasing of deformation temperature and firstly increases and then decreases with the increasing of strain rate.At the same time,the activation energy is affected by the coupled effect of strain and strain rate.

关 键 词：锻态42CrMo钢 高温压缩变形 本构模型 激活能 流动应力 

分 类 号：TG333[金属学及工艺—金属压力加工]