Cellular automaton simulation of dynamic recrystallization behavior in V-10Cr-5Ti alloy under hot deformation conditions
(1. National Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology, Harbin 150001, China;
2. Institute of Machinery Manufacturing Technology, China Academy of Engineering Physics, Mianyang 621900, China;
3. China Nuclear Industry No. 23 Construction Co., Ltd., Beijing 101300, China)
2. Institute of Machinery Manufacturing Technology, China Academy of Engineering Physics, Mianyang 621900, China;
3. China Nuclear Industry No. 23 Construction Co., Ltd., Beijing 101300, China)
Abstract: The deformation behavior of V-10Cr-5Ti alloy was studied on the Gleeble-1500 thermomechanical simulator at the temperatures of 950-1350 °C, 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.
Key words: V-10Cr-5Ti alloy; hot deformation; dynamic recrystallization; cellular automaton; microstructure; numerical simulation; grain refinement