Numerical simulation of solidification structure formation in high Mn steel casting using cellular automaton method

Abstract

Numerical simulation analysis was carried out to predict the solidification grain structure in commercial scale high Mn steel casting using the cellular automaton (CA) method, and the critical pouring temperature to produce fine equiaxed structure was examined. In the present simulation, heterogeneous nucleation in bulk liquid and the crystal multiplication due to the 'Big Bang' mechanism were taken into account. Fine equiaxed grain structure was formed in the simulation with low pouring temperature of 1 638 K and mixed structure with columnar and equiaxed crystals was formed with higher pouring temperature of 1 663 K. These simulated structures agreed with experimentally observed structures in real castings. To determine the critical pouring temperature to produce fine equiaxed crystal structure, CA simulations for several pouring temperatures were carried out and it was predicted that to obtain fine equiaxed grains in the high Mn steel casting, it will be required to cast with pouring temperature of less than 1 648 K. © 2008 ISIJ.