Chen Xuewen, Lian Tingting, Zhang Bo, Du Yuqing, Du Kexue, Liu Bingqi, Li Zhipeng, Tian Xuanhe, Jung Dong-Won
School of Materials Science and Engineering, Henan University of Science and Technology, 263 Kaiyuan Avenue, Luoyang 471023, China.
Faculty of Mechanical, Jeju National University, Jeju Island 63243, Korea.
Materials (Basel). 2021 Apr 26;14(9):2216. doi: 10.3390/ma14092216.
As a novel kind of cold roller steel, Cr8 alloy steel has the characteristics of high hardness, high wear resistance and good toughness, which can effectively prolong the service life of the roller that is an important part of the steel rolling mill. How to accurately define the constitutive model parameters of metal materials is the major problem, because it seriously affects the accuracy of numerical simulation results of the roller hot forming process. In the study of Cr8 alloy steel's thermal deformation behavior of the present paper, the high temperature compression test was done on a Gleebel-1500D thermal/force simulation testing machine. A novel method of parameter identification was proposed based on inverse optimization. The Hansel-Spittel constitutive model was established by using the inverse optimization method. To carry out the verification on the accuracy of the established constitutive model, the predicted flow-stress of constitutive model was made a contrast to the experimental flow-stress, and the standard statistical parameters were also applied to further evaluation. The results showed a relatively high prediction accuracy of the Hansel-Spittel constitutive model based on the inverse optimization algorithm. Meanwhile, to obtain optimal parameters of Cr8 alloy steel in the thermal processing, 3D thermal processing maps concerning strain-rate, strain and temperature were built based on the dynamic material model. According to the 3D processing map, the most adequate thermal processing parameters of Cr8 alloy steel were obtianed as follows: strain 0.2-0.4, strain-rate 0.05-0.005 s, temperature 1100-1150 °C.
作为一种新型冷轧辊用钢，Cr8合金钢具有硬度高、耐磨性高和韧性好的特点，能有效延长轧钢机重要部件轧辊的使用寿命。如何准确确定金属材料的本构模型参数是主要问题，因为它严重影响轧辊热成形过程数值模拟结果的准确性。在本文对Cr8合金钢热变形行为的研究中，在Gleebel-1500D热/力模拟试验机上进行了高温压缩试验。提出了一种基于逆优化的参数识别新方法。采用逆优化方法建立了Hansel-Spittel本构模型。为验证所建立本构模型的准确性，将本构模型预测的流变应力与实验流变应力进行对比，并应用标准统计参数进行进一步评估。结果表明，基于逆优化算法的Hansel-Spittel本构模型具有较高的预测精度。同时，为了获得Cr8合金钢热加工的最优参数，基于动态材料模型构建了关于应变速率、应变和温度的三维热加工图。根据三维加工图，得出Cr8合金钢最适宜的热加工参数如下：应变0.2 - 0.4，应变速率0.05 - 0.005 s，温度1100 - 1150℃。
