Simulated multipass deformation experiments were carried out via torsion testing on a Ti-6Al-4V alloy in the two-phase region under both isothermal and continuous cooling conditions. Flow softening was observed during the isothermal multipass deformation tests as indicated by the evolution of the mean flow stress (MFS). The MFS values increased with interpass time from 2 s to 32 s. Using BSE-SEM characterization techniques, dynamic phase transformation (alpha to beta) and coarsening of the alpha phase took place. The quantitative results indicate that the alpha phase transforms into beta during straining, but it retransforms statically into alpha by amounts that increase with interpass time. The flow softening observed is the net result of softening by dynamic transformation and hardening by reverse transformation.

通过等温和连续冷却条件下的两相区Ti-6Al-4V合金的扭转试验，进行了模拟的多道次变形实验。平均流动应力（MFS）的演变表明，在等温多次通过变形试验中观察到了流动软化。MFS值随着间隔时间从2 s增加到32 s。使用BSE-SEM表征技术，发生了动态相变（α到β）和α相的粗化。定量结果表明，在拉伸过程中，α相转变为β，但随着相交时间的增加，它会静态地重新转变为α。观察到的流动软化是通过动态转变软化和通过反向转变硬化的最终结果。