使用Gleeble-3500型热模拟试验机对轧制态TC21合金在α+β两相区进行压缩变形试验，研究了合金在不同热变形温度（870~960℃）、不同应变速率（0.001~1 s^-1）条件下的组织和流变应力曲线，建立了流变应力本构方程和动态再结晶位错密度模型，并进行了显微组织模拟及验证。结果表明：合金的流变应力曲线呈现的软化机制以动态再结晶为主；应变速率一定时，变形后组织中α相含量随变形温度升高不断减少，α相尺寸先增大后减小；变形温度为870，900℃时，α相尺寸随应变速率增大而先减小后增大，变形温度升至930℃靠近相变点时，α相含量急剧减少，随应变速率增大，β相晶粒发生动态再结晶，晶粒细化；建立的应力计算模型用于峰值应力的预测，其结果较为准确，平均相对误差为6.274%；基于流变应力本构方程和位错密度模型进行的动态再结晶组织演变模拟结果与试验得到的显微组织基本相符，计算模型较为准确。

The compression deformation test of as-rolled TC21 alloy in α+β two-phase region was carried out by using Gleeble-3500 thermal simulation test machine. The microstructure and flow stress curves of the alloys at different hot deformation temperatures (870-960℃) and strain rates (0.001-1 s^-1) were studied. The flow stress constitutive equation and dynamic recrystallization dislocation density model were established, and the microstructure was simulated and verified. The results show that the softening mechanism of flow stress curve of the alloy was mainly dynamic recrystallization. When the strain rate was constant, the content of α phase in the deformed microstructure decreased continuously with increasing deformation temperature, and the size of α phase increased first and then decreased. When the deformation temperature was 870℃ and 900℃, the size of α phase decreased first and then increased with increasing strain rate. When the deformation temperature reached 930℃, which was close to the transformation point, the α phase content decreased sharply, and the β phase grain was dynamically recrystallized, and the grain size was refined. The established stress calculation model was used to predict the peak stress, and the results were relatively accurate with an average relative error of 6.274%. The simulation results of the dynamic recrystallization microstructure based on the flow stress constitutive equation and the dislocation density model were basically consistent with the microstructure obtained by the experiment, and the calculation model was relatively accurate.