Development of a CA-FVM Model withWeakened Mesh Anisotropy and Application to Fe-C Alloy

Abstract

In order to match the growth of the decentered square and the evolution of the interface cell in a two-dimensional cellular automaton-finite volume method (CA-FVM) model with decentered square algorithm, the present work first alters the determination of the half length of the square diagonal according to the preferential growth orientation, and then modifies the interface evolution considering the contribution of neighboring solid cells. Accordingly, the sharp interface (physical basis of the model), the growth orientation, and the growth consistence are reasonably guaranteed. The CA-FVM model presents some capabilities in predicting the free growth of equiaxed dendrites. With the increase of the cooling rate, the solidification structure gradually changes from cell to dendrite, and the solute segregation becomes more severe. Meanwhile, the predicted solute segregation under the intensive cooling condition is consistent with the calculation by Ueshima model at the initial solidification stage. The predicted competition behavior of columnar dendrites is qualitatively consistent with the observation in the continuously cast steel billet. The predicted dendrite arm spacings are close to the measurements.