EFFECT OF TWO FREE DENDRITIC GROWTH MODELS ON THE SIMULATION OF MICROSTRUCTURE FORMATION IN SOLIDIFICATION PROCESS OF Fe-0.4WT.C ALLOY

摘要

The crystal nucleation and free dendritic growth during solidification is the key factor in determining the microstructure evolutions and morphology. Microscopic simulation using available nucleation and dendritic growth models can be a useful tool for understanding and controlling of such evolution. The present study was conducted to simulate the solidification microstructure formation of Fe-0.4wt.%C alloy using the CALCOSOFT software based on a 3D cellular automaton-finite element (CAFE) method. The two kinds of free dendritic growth models, the LGK model and the KGT model, were used respectively to describe the dendrite growth kinetics in solidification process. The effect of convective heat transfer coefficients on the microstructure was also studied. The calculated results showed that more columnar grains appear with the convective heat transfer coefficients increasing in spite of using different growth models. The simulated results are different under lower convective heat transfer coefficients, but when the convective heat transfer coefficient increases, the results are similar.