Hot deformation behavior and constitutive modeling of Q345E alloy steel under hot compression  

作　　者：钱东升 彭亚亚 邓加东 

机构地区：[1]School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China [2]School of Automotive Engineering, Wuhan University of Technology, Wuhan 430070, China [3]Hubei Key Laboratory of Advanced Technology for Automotive Components, Wuhan 430070, China [4]State Key Laboratory of Materials Processing and Die & Mould Technology, Wuhan 430070, China

出　　处：《Journal of Central South University》2017年第2期284-295,共12页中南大学学报（英文版）

基　　金：Project(51135007)supported by the National Natural Science Foundation of China;Project(IRT13087)supported by the Innovative Research Team Development Program of Ministry of Education of China;Project(2012-86)supported by the High-end Talent Leading Program of Hubei Province,China;Project(2012-P08)supported by State Key Laboratory of Materials Processing and Die&Mould Technology,China

摘　　要：Q345E as one of typical low alloy steels is widely used in manufacturing basic components in many fields because of its eminent formability under elevated temperature. In this work, the deformation behavior of Q345E steel was investigated by hot compression experiments on Gleeble-3500 thermo-mechanical simulator with the temperature ranging from 850 ℃ to 1150 ℃ and strain rate ranging from 0.01 s-1 to 10 s-1. The experimental results indicate that dynamic softening of Q345E benefits from increasing deformation temperature and decreasing strain rate. The mathematical relationship between dynamic softening degree and deformation conditions is established to predict the dynamic softening degree quantitatively, which is further proved by some optical microstructures of Q345E. In addition, the experimental results also reveal that the stress level decreases with increasing deformation temperature and decreasing strain rate. The constitutive equation for flow stress of Q345E is formulated by Arrihenius equation and the modified Zener-Hollomon parameter considering the compensation of both strain and strain rate. The flow stress values predicted by the constitutive equation agree well with the experimental values, realizing the accurate prediction of the flow stress of Q345E steel under hot deformation.Q345E as one of typical low alloy steels is widely used in manufacturing basic components in many fields because of its eminent formability under elevated temperature. In this work, the deformation behavior of Q345 E steel was investigated by hot compression experiments on Gleeble-3500 thermo-mechanical simulator with the temperature ranging from 850 °C to 1150 °C and strain rate ranging from 0.01 s^(-1) to 10 s^(-1). The experimental results indicate that dynamic softening of Q345 E benefits from increasing deformation temperature and decreasing strain rate. The mathematical relationship between dynamic softening degree and deformation conditions is established to predict the dynamic softening degree quantitatively, which is further proved by some optical microstructures of Q345 E. In addition, the experimental results also reveal that the stress level decreases with increasing deformation temperature and decreasing strain rate. The constitutive equation for flow stress of Q345 E is formulated by Arrihenius equation and the modified Zener-Hollomon parameter considering the compensation of both strain and strain rate. The flow stress values predicted by the constitutive equation agree well with the experimental values, realizing the accurate prediction of the flow stress of Q345 E steel under hot deformation.

关 键 词：hot deformation behavior dynamic softening flow stress constitutive model 

分 类 号：TG142.33[一般工业技术—材料科学与工程] TQ323.4[金属学及工艺—金属材料]