42CrMo4钢的高温变形行为及本构模型  

High Temperature Deformation Behavior and Constitutive Model of 42CrMo4 Steel

作　　者：窦存超 孙振栋 郭宁[1] 沈德鹏 刘哲 程林 刘永超 唐炳涛 DOU Cunchao;SUN Zhendong;GUO Ning;SHEN Depeng;LIU Zhe;CHENG Lin;LIU Yongchao;TANG Bingtao(Faculty of Mechanical Engineering,Qilu University of Technology(Shandong Academy of Sciences),Jinan 250353,China;Jinlei Technology Co.,Ltd.,Jinan 271105,China)

机构地区：[1]齐鲁工业大学(山东省科学院)机械工程学院,山东济南250353 [2]金雷科技股份公司,山东济南271105

出　　处：《热加工工艺》2025年第5期77-85,共9页Hot Working Technology

基　　金：国家自然科学基金资助项目(52275344);泰山产业领军人才工程蓝色人才专项项目(TSLS20221101)。

摘　　要：采用Gleeble热模拟试验机进行等温压缩实验(变形量60%),测得温度(950~1200℃)和应变速率(0.001~1 s^(-1))下42CrMo4钢的真应力-应变曲线。结果显示,其流变应力曲线在大多变形条件下表现出动态再结晶的特征,流变应力随变形温度的降低和应变速率的升高而增大。计算得到其热变形激活能为382.5122 kJ/mol,并构建了“两段式”高温流动应力模型,模型计算值与实验值相关系数高达0.99784。用作图法求解加工硬化率,确定了临界应变和峰值应变,得到了42CrMo4钢热变形特性的动态再结晶数学模型。将高温流动应力模型和微观组织演变模型嵌入Deform 3D二次开发子程序,对某工件镦粗成形进行数值模拟,获得其平均晶粒尺寸和动态再结晶分数。结果表明,模拟结果与实验结果吻合性较好,验证了本文建立的42CrMo4钢的本构方程的准确性。Gleeble thermal simulation testing machine was used to carry out the thermal compression experiments with deformation amount of 60%.The true stress-true strain curves at high temperature of 950-1200℃and strain rate of 0.001-1 s^(-1)were obtained.The results show that the flow stress curves show the dynamic recrystallization characteristics under the most deformation conditions.The rheological stress increases with the deformation temperature decreasing and the strain rate increasing.The hot deformation activation energy is calculated to be 382.5122 kJ/mol.A"two-stage"high-temperature flow stress constitutive model was constructed.The correlation coefficient between the calculated and experimental values of the model is as high as 0.99784.The critical and peak strains were determined by obtaining the work-hardening rate using the graphical method.A dynamic recrystallization model of 42CrMo4 steel considering the hot deformation characterization was established.The high temperature constitutive model and the microstructure evolution model were embedded into the Deform 3D subroutine to perform a numerical simulation of upsetting of a workpiece to obtain the average grain size and the dynamic recrystallization volume fraction.The results show that the simulation results are in good agreement with the experimental results,which verifies the accuracy of the constitutive model of 42CrMo4 steel.

关 键 词：42CrMo4 等温压缩 流变应力 本构方程 数值模拟 

分 类 号：TG142.1[一般工业技术—材料科学与工程]