H156热作模具钢动态再结晶的实验与数值模拟研究  

Experiment and numerical simulation study on dynamic recrystallization for H156 hot work die steel

作　　者：杜帅 李颖 李敏 何文武[1] Du Shuai;Li Ying;Li Min;He Wenwu(School of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,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

出　　处：《锻压技术》2023年第1期245-252,共8页Forging & Stamping Technology

基　　金：山西省重点学科建设经费资助项目(2019KJ029)。

摘　　要：通过Gleeb-1500D热模拟机,对H156热作模具钢进行单道次热压缩实验。实验中,变形温度控制在850~1220℃,应变速率控制在0.001~1 s^(-1),真应变为0.7。通过采集数据获得真应力-真应变曲线,得出流变应力与热变形参数之间的数学关系,建立了动态再结晶模型,并借助光学显微镜对不同热变形参数下实验样品的微观组织进行观察分析,建立了晶粒尺寸模型。通过DEFORM-3D有限元软件对H156热作模具钢的动态再结晶行为进行模拟,探究热变形参数对实验材料动态再结晶(DRX)行为的影响。结果表明:随着变形温度的增加,DRX体积分数增加,DRX晶粒分布越均匀;较大的应变速率会导致变形时间缩短,DRX区域减小,细小晶粒缺少充足的时间发生形核长大。因此,提高变形温度、降低应变速率有助于动态再结晶的完成。数值模拟结果与实验结果较吻合,验证了模型的准确性。For H156 hot work die steel, a single-pass thermal compression experiment was conducted by Gleeb-1500D thermal simulator under the deformation temperature of 850-1220 ℃, the strain rate of 0.001-1 s^(-1)and the true strain of 0.7, and the true stress-true strain curve was obtained by collected data. Then, the mathematical relationship between rheological stress and thermal deformation parameters was obtained, and a dynamic recrystallization model was established. Furthermore, the microstructure of experimental samples under different thermal deformation parameters was observed and analyzed by optical microscope, and the grain size model was established. Finally, the dynamic recrystallization behavior of H156 hot work die steel was simulated by finite element software DEFORM-3D, and the influences of thermal deformation parameters on the dynamic recrystallization behavior of experimental materials were explored. The results show that with the increasing of deformation temperature, and the DRX volume fraction increases, the distribution of DRX grains becomes more uniform. A large strain rate shortens the deformation time, reduces the DRX area, and the fine grains lack sufficient time for nucleation and growth. Therefore, increasing the deformation temperature and decreasing the strain rate are conducive to the completion of dynamic recrystallization, and the numerical simulation results are consistent with the experimental results, which verifies the accuracy of the model.

关 键 词：H156热作模具钢 动态再结晶模型 微观组织 变形温度 应变速率 

分 类 号：TG142.5[一般工业技术—材料科学与工程]