Numerical simulation of cellular automaton in vacuum arc remelting during the solidification process

Abstract

In this paper, the finite element and cellular automaton coupling (CAFE) model is used to simulate the solidification process of a large ingot during vacuum consumable arc melting (VAR). The effects of melting temperature, melting rate, and mold cooling coefficient on temperature field distribution and solidification structure were studied by simulation. The results show that the microstructure predicted by the numerical method is consistent with the experimental results. As the melting temperature increases from 1500 °C to 1800 °C, the depth of the molten pool increases from 14 mm to 24 mm, the width of the mushy zone decreases from 10 mm to 9 mm, and the average radius of the grains increases from 584.3 μm to 679 μm. With the increase in melting rate from 6 kg min−1 to 12 kg min−1, the maximum depth of the molten pool increases from 4 mm to 32 mm, the width of the mushy zone increases from 8 mm to 13 mm, and the average grain radius decreases from 943 μm to 497 μm. As the cooling coefficient of the mold increases from 1000 W m−2·K−1 to 5000 W m−2·K−1, the depth of the molten pool decreases from 16.7 mm to 12 mm, the width of the mushy zone decreases from 7.3 mm to 5.9 mm, and the average radius of the grains increases from 630 μm to 1303.5 μm.