热变形条件下V-10Cr-5Ti合金动态再结晶行为的元胞自动机模拟（英文）

Cellular automaton simulation of dynamic recrystallization behavior in V-10Cr-5Ti alloy under hot deformation conditions

通过在Gleeble-1500热模拟压缩机上对V-10Cr-5Ti合金进行温度为950～1350℃、应变速率为0.01～10 s^(-1)的热模拟压缩实验,并基于Arrhenius模型、位错密度模型、形核模型和晶粒长大模型,建立一种元胞自动机(CA)模型来模拟和表征动态再结晶过程中的组织演变。结果表明:流动应力对变形速率和变形温度具有强烈的依赖性,利用Arrhenius模型预测的应力值与实际测量值的误差小于8%。CA模型计算得到的初始平均晶粒尺寸为86.25μm,与试验测量得到的85.63μm相近。模拟表明:初始晶粒尺寸对动态再结晶组织演化影响并不显著,而提高应变速率或降低变形温度均可细化再结晶晶粒。

The deformation behavior of V-10Cr-5Ti alloy was studied on the Gleeble-1500 thermomechanical simulator at the temperatures of 950-1350℃, and the strain rates of 0.01-10 s^-1. Based on the Arrhenius model, dislocation density model, nucleation model and grain growth model, a numerical cellular automaton (CA) model coupling simulation of hot deformation is established to simulate and characterize the microstructural evolution during DRX. The results show that the flow stress is fairly sensitive to the strain rate and deformation temperature. The error between the predicted stress by the Arrhenius model and the actual measured value is less than 8%. The initial average grain size calculated by the CA model is 86.25 μm, which is close to the experimental result (85.63 μm). The simulations show that the effect of initial grain size on the dynamic recrystallization microstructure evolution is not significant, while increasing the strain rate or reducing the temperature can refine the recrystallized grains.