车轴用LZ50钢的热变形行为及高温塑性本构方程  

Hot deformation behavior and high temperature plastic constitutive equation of LZ50 steel for axle

作　　者：郑晓华[1] 柏永青[1] 贾晓斌 Zheng Xiaohua;Bai Yongqing;Jia Xiaobin(College of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan Shanxi 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：《金属热处理》2020年第10期31-34,共4页Heat Treatment of Metals

基　　金：国家自然科学基金(51775361)。

摘　　要：借助Gleeble-1500D热模拟试验机,在温度1050~1200℃,应变速率0.01~1 s^(-1),变形量在50%的条件下对LZ50高速铁路车轴钢试样进行热变形压缩试验。通过试验测得该材料不同工艺参数下的真应力-应变曲线,采用Arrhenius双曲正弦函数推导LZ50钢的高温塑性本构方程,并分析了不同热加工条件下LZ50钢的动态再结晶行为。结果表明,LZ50钢对温度和应变速率的变化较为敏感,温度越高,应变速率越低,所对应流动应力值越小。LZ50钢的变形激活能为217920.626 J/mol。变形温度越高,应变速率越低,再结晶现象越容易发生。Taking LZ50 steel for high-speed railway axle as the research object,Gleeble-1500D thermal simulation machine was used to conduct the hot deformation compression experiment at the temperature of 1050-1200℃,with the strain rate of 0.01-1 s-1,and 50%deformation.The true stress-strain curves of LZ50 steel under different process parameters were obtained by experiments.And the plastic constitutive equation of LZ50 steel at high temperature was deduced by Arrhenius hyperbolic sine function.The dynamic recrystallization behavior of LZ50 steel under different thermal deformation conditions was analyzed.The results show that LZ50 steel is sensitive to the changes of temperature and strain rate.With the increase of temperature and the decrease of strain rate,the flow stress decreases.The deformation activation energy of LZ50 steel is 217920.626 J/mol.The higher the deformation temperature,the lower the strain rate is,and the dynamic recrystallization is more likely to occur.

关 键 词：LZ50钢 本构方程 热变形激活能 动态再结晶 

分 类 号：TG115.21[金属学及工艺—物理冶金] TG142.7[金属学及工艺—金属学]