Study of microstructure simulation of spheroidal graphite cast iron

Based on the solidification kinetics, the mathematical model of microstruct ure formation of spheroidal graphite cast iron were established and the dev eloped codes were verified with the sample castings. In addition, four auto motive spheroidal graphite iron castings were simulated by using this model . The simulated results were compared and discussed with the quantitative e xperimental results of both sample castings and four automotive castings. I t is concluded that the nucleation and growth of graphite spheres are mainl y determined by the cooling rate during eutectic transformation. The conten ts of ferrite and pearlite of the matrix are governed by both the super-coo ling of eutectoid transformation and the number of nodule counts during eut ectic solidification, and the model of eutectoid transformation should be f urther improved.