摘要
楔横轧技术在成形轴类零件时具有广阔的应用前景,为实现高铁车轴材料LZ50钢楔横轧成形,需构建能准确描述LZ50钢高温流变行为的本构模型。修正的Johnson-Cook和Zerilli-Armstrong模型对金属流变应力的预测较为精确,可建立LZ50钢关于这2种模型的流变应力本构方程,同时为精确分析LZ50钢在大型轴类件楔横轧成形过程中的变形行为,需进一步分析2种模型在不同温度的平均相对误差EAR、相关系数R以及均方差RMSE,从而判断模型的适用性,为楔横轧在线生产提供理论依据。通过Gleeble-3800热模拟试验机在不同压缩温度(900、1000、1100℃)、不同应变速率(0.1、1、10 s^(-1))条件下对LZ50钢进行热压缩试验;以1000℃和0.1 s^(-1)作为参考温度和参考应变速率,并通过修正的Johnson-Cook和Zerilli-Armstrong模型构建了2种高温流变应力本构方程,对比在0.3~0.8应变范围内2种模型预测流动应力与实测流动应力的平均相对误差EAR、相关系数R以及均方差RMSE。结果发现,修正的Johnson-Cook和Zerilli-Armstrong模型平均相对误差EAR分别为3.8%和6.9%,相关系数R分别为0.986和0.974,均方差RMSE分别为4.9798 MPa和8.0501 MPa;进一步对比2种模型在不同温度条件的平均相对误差EAR、相关系数R以及均方差RMSE,发现Johnson-Cook模型在预测900℃和1000℃的流变应力时具有更好的预测精度,而在预测1100℃的流变应力时Zerilli-Armstrong模型预测精度更高。
The cross wedge rolling technology has broad application prospects in forming axle parts.Therefore,in order to realize the cross wedge rolling forming of high-speed railway axle material LZ50 steel,it is necessary to build a constitutive model that can accurately describe its high-temperature rheological behavior.The modified Johnson Book and Zerilli Armstrong models are more accurate for predicting the metal flow stress,which can establish the constitutive equation of flow stress of LZ50 steel for these two models.At the same time,in order to accurately analyze the deformation behavior of LZ50 steel in the process of cross wedge rolling of large shaft parts,it is necessary to further analyze the average relative error EAR,correlation coefficient R and mean square error RMSE of the two models at different temperatures to judge the applicability of the model,It provides a theoretical basis for the online production of cross wedge rolling.The hot compression experiments were carried out on LZ50 steel by Gleeble-3800 thermal simulation testing machine at different compression temperatures(900,1000,1100℃)and strain rates(0.1,1,10 s^(-1)).The true compression strain was 0.8,and 1000℃and 0.1 s^(-1)were used as reference temperatures and strain rates.Two high temperature rheological stress constitutive equations were constructed through the modified Johnson-Cook and Zerilli-Armstrong models,Compare the average relative error EAR,correlation coefficient R and mean square error RMSE of the two models'predicted flow stress and measured flow stress in the strain range of 0.3-0.8.The results showed that the average relative error EAR of the modified Johnson-Cook and Zerilli-Armstrong models was 3.8%and 6.9%respectively,R were 0.986 and 0.974 respectively,and RMSE was 4.9798 MPa and 8.0501 MPa respectively.By comparing the average relative error EAR,correlation coefficient R and mean square error RMSE of the two models under different temperature conditions,it is found that Johnson-Cook model has better prediction accurac
作者
李诗谦
何涛
杜向阳
霍元明
贾东昇
李汉林
LI Shi-qian;HE Tao;DU Xiang-yang;HUO Yuan-ming;JIA Dong-sheng;LI Han-lin(School of Mechanical and Automotive Engineering,Shanghai University of Engineering Science,Shanghai 201620,China)
出处
《钢铁》
CAS
CSCD
北大核心
2023年第4期148-156,共9页
Iron and Steel
基金
国家重点研发计划资助项目(2018YFB1307900)
国家自然科学基金资助项目(52275350)
上海市自然科学基金资助项目(20ZR1422100)。
关键词
LZ50钢
流变应力
本构模型
热压缩试验
均方差
LZ50 steel
flow stress
constitutive model
thermal compression experiment
root mean squared error
