Phase field simulation on the synergistic variation of solidification structure morphology and segregation for continuous casting process of high carbon steel billets

The Fe-0.82 wt.% C binary alloy was taken as an example to simulate the solidification process of high carbon steel continuous casting billet by phase field method. Synergistic changes of solidification structure morphology and solute element segregation at different solidification stages were studied. The thickness of solute diffusion layer at solidification interface decreased with increasing cooling rate and undercooling. Increasing the degree of undercooling and decreasing the cooling rate was beneficial to increase the degree of complexity. For the segregation of C element, in the early stage of solidification, the greater the degree of undercooling and the cooling rate, the smaller the segregation ratio; and in the late stage of solidification, the degree of undercooling had little effect on segregation ratio, and the greater the cooling rate, the greater the segregation ratio. Therefore, high undercooling and cooling rate should be maintained in the early stage of solidification.