Modelling of Density Changes of Nodular Cast Iron During Solidification by Cellular Automaton

Abstract

Results of predictions of nodular cast iron density changes during solidification are presented. These changes were calculated by using a mathematical model which bases on a Cellular Automaton - Finite Differences (CA-FD) method. The CA-FD model takes into account, among others, the independent nucleation of graphite and austenite as a function of undercooling, the migration rate of the grains’ borders, non-uniform distribution of temperature and concentration in the calculation domain, diffusion of the carbon in the liquid and the austenite. All simulation were performed at various: nucleation intensity and the eutectic saturation. It has been shown and proofed by other authors that the shrinkage phenomena take place at three stages: pre-eutectic shrinkage, eutectic expansion, and final shrinkage.