Cellular Automaton Simulation of Dendrite Growth in Solidification Process of Cr17 Stainless Steel under Mechanical Vibration

Herein, a coupled model of temperature field and dendrite growth is built to examine the solidification microstructure of Cr17 stainless steel under vibration. The temperature field is calculated with ANSYS FLUENT software. In addition, considering solute diffusion and local curvature, a low grid anisotropic cellular automaton (CA) model is used to simulate the dendrite growth. To verify the major source of crystal nucleus in the melts, a mechanical model of dendrite fracture is built, and an investigation is conducted on the critical condition of grain dissociation. As indicated from the results, the dendrites are stripped and dissociated into the melt when the vibration frequency and amplitude values exceed the critical condition of dendrite fracture, the grains are dissociated more easily, and the more equiaxed grains are indicated in the melt with the increase in the vibration frequency. It is preliminarily demonstrated that vibration can facilitate the dendrites to break and be dissociated from the chilling generator surface. The simulation results comply with the experiment.