Numerical prediction of microstructure evolution of high-speed railway axle formed using hot cross wedge rolling

作     者：Huo, Yuanming Huo, Cunlong Ren, Xu He, Tao Hosseini, Seyed Reza Elmi Wang, Baoyu Cui, Yongliang Jia, Changyuan Liu, Keran Du, Xiangyang 

作者机构：Shanghai Univ Engn Sci Sch Mech & Automot Engn Shanghai 201620 Peoples R China Iran Univ Sci & Technol IUST Sch Met & Mat Engn Tehran Iran Univ Sci & Technol Beijing Sch Mech Engn Beijing 100083 Peoples R China Taiyuan Heavy Ind Railway Transit Equipment Co Ltd Taiyuan 030032 Peoples R China 

出 版 物：《MATERIALS TODAY COMMUNICATIONS》 (Mater. Today Commun.)

年 卷 期：2023年第35卷

核心收录：

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：National Natural Science Foundation of China Natural Science Foundation of Shanghai [20ZR1422100] International cooperative scientific research platform of SUES Shanghai Sci- ence and Technology Commission Key Project 

主　　题：High-speed railway axle Cross wedge rolling Dynamic recrystallization Numerical simulation Process parameters optimization 

摘      要：The ununiform distribution of the grain size and coarse crystals is easy to be appeared in the high-speed railway axle (HSRA) formed by hot cross wedge rolling (CWR). It seriously reduces the comprehensive mechanical properties of the HSRA. It is vital to numerically predict microstructure evolution, so that the mixed and coarse crystals can be accurately controlled via process parameters optimization. In this study, the microstructure evolution model of the 40CrNiMo steel was developed and implemented into the DEFORM-3D software by programming a user subroutine to simulate hot upsetting. Microstructure of specimens after hot upsetting experiment was investigated to validate the finite element (FE) prediction model of microstructure evolution. The simulation results were close to the experimental results, which verifies that the established microstructure evolution model has a good predictability. The developed microstructure evolution model and the FE prediction system of hot CWR were used to simulate the forming of HSRA. Hot CWR simulations of HSRA was conducted at rolling temperature of 1000 degrees C and rolling sped of 1.5 r/min with initial grain size of 200um. Numerical prediction of dynamic recrystallization (DRX) volume fraction and average grain size in three segments of CWR, such as wedge entering segment, widening segment and finishing segment, were carried out to study the microstructure evolution of CWR. Results show that the maximum average grain size locates in the heart of hub axle section, which is smaller than grade 5 and above (d 62.5 m). It indicates that the microstructure of HSRA after CWR meet the requirements of grain structure grade in international standard of EN13261. Effects of rolling temperatures, rolling speeds and initial grain sizes on the microstructure distribution after hot CWR were analyzed using FE simulations for 40CrNiMo steel. The rolling temperature of 1050 degrees C, rolling speed of 6 r/min and initial average g