摘要
采用Gleeble-3800热模拟试验机在950~1050℃变形温度范围及0.01~0.1 s^(-1)应变速率条件下对300M超高强钢进行热压缩实验。基于动态材料模型建立了应变补偿本构方程,研究了实验钢在高温下的热变形行为。采用电子背散射衍射技术结合ARPGE晶体学分析软件,研究了不同变形条件下超高强钢的显微组织演变规律。结果表明,在实验温度范围内,温度升高通过促进动态回复降低位错密度,导致流变应力下降;而应变速率增加引起几何必要位错密度增加,致使流变应力上升。晶体学分析揭示了协调塑性变形模式下马氏体变体呈现显著取向择优特性。此外,300M超高强钢的热变形激活能为353.37 kJ·mol^(-1),建立的本构方程相关系数达到0.99703,平均相对误差仅为1.80%,表明该方程能够有效预测不同变形条件下300M超高强钢的流变应力。
The hot compression experiments of 300M ultra-high strength steel was conducted on the Gleeble-3800 thermal simulation ex-perimental machine at the deformation temperature of 950-1050℃and the strain rate of 0.01-0.1 s-1.Then,based on the dynamic ma-terial model,the strain compensation constitutive equation was established,and the hot deformation behavior of experimental steel at high temperatures was studied.Furthermore,the microstructure evolution laws of ultra-high strength steel under different deformation conditions were studied by electron backscatter diffraction technology combined with ARPGE crystallographic analysis software.The results indicate that within the experimental temperature range,the increase in temperature reduces dislocation density by promoting dynamic recovery,resulting in a decrease in the rheological stress.While the increase in strain rate leads to an increase in geometrically necessary dislocation density,resulting in an increase in the rheological stress.Crystallographic analysis reveals that the martensite variants exhibit significant orientation preference characteristics under coordinated plastic deformation mode.In addition,the hot deformation activation energy of 300M ultra-high strength steel is 353.37 kJ·mol^(-1),the correlation coefficient of the established constitutive equation reaches 0.99703,and the average rela-tive error is only 1.80%,indicating that the equation can effectively predict the rheological stress under different deformation conditions.
作者
许瑜倩
Xu Yuqian(College of Metallurgical Engineering,Anhui University of Technology,Ma′anshan 243000,China)
出处
《锻压技术》
北大核心
2025年第6期221-233,共13页
Forging & Stamping Technology
关键词
300M超高强钢
热变形行为
本构方程
动态再结晶
流变应力
300M ultra-high strength steel
hot deformation behavior
constitutive equations
dynamic recrystallization
rheological stress
