Abstract A comprehensive investigation of the process parameters–mechanical properties–microstructures relationship is essential for the manufacturing of large titanium alloy components. In this work, the macro hot deformation behaviors and microstructural evolution of TA31 with a forged equiaxed structure were studied in the range of 850–1,020 °C and 0.001–0.1 s −1 . A modified Johnson–Cook model incorporating the coupling effects of strain, temperature, and strain rate is developed to accurately capture the strain softening phenomenon for TA31. The parameters of the modified constitutive model are determined by the global optimization method, resulting in a correlation coefficient of 8.85 % and an average absolute relative error of 0.9932. It has been observed that dynamic recrystallization (DRX) occurs within the temperature range of 850–980 °C, primarily acting as the dominant softening mechanism in the lower (α+β) region. The contribution of dynamic recovery (DRV) to the softening process gradually increases in the upper (α+β) region and the β single-phase region. The change in the deformation mechanism is related to the extent of distortion energy and the effects of thermal activation. This study is important for the microstructure tailoring and processing optimization, which could offer practical guidance for industrial production applications.
Liang et al. (Tue,) studied this question.