通过Gleeble-1500热模拟单轴压缩试验，研究了一种含1.79% Al (质量分数)的以Al替代Si微合金化高强度钢在温度为900~1100℃、应变速率为0.01~30 s-1条件下的热变形行为.建立了考虑应变量对材料常数影响的双曲正弦本构方程，利用建立的本构方程预测的应力-应变曲线与实验值吻合良好，表明建立的本构方程可以对实验钢的流变应力给出相对准确的预测.建立了实验钢的加工图，根据加工图分析确定了实验钢的动态再结晶区为1000~1100℃和0.01~1 s-1.组织观察表明在动态再结晶区实验钢发生了动态再结晶，而失稳区对应的组织出现了变形集中带或“项链”组织.最后将建立的本构方程和加工图联合运用，为更全面地研究实验钢在不同变形条件下的热变形行为提供了方法.
The compressive deformation behavior of a new microalloyed high-strength steel containing 1.79% Al was investigated at temperatures from 900 to 1100℃ and strain rates from 0.01 to 30 s-1 on a Gleeble-1500 thermo-simulation machine. A hyperbolic sine equation with strain-dependent constants was developed for the steel. The predicted flow stress curves by the constitutive equation well agreed with experimental results, indicating that the constitutive equation can give a relatively accurate estimate of flow stress for the steel. According to processing map analysis, the dynamic recrystallization zone of the steel was determined as 1000 to 1100℃ and 0.01 to 1 s-1 . Microstructure observation showed that dynamic recrystallization occurred in this dynamic recrystallization zone, and in the instability zone, flow localization and necklace structure was observed. Finally, a combination of the constitutive equation and pro-cessing map provided a method for comprehensively investigating the hot deformation behavior of the steel under different conditions.