9th International Conference on Modeling and Simulation of Metallurgical Processes in Steelmaking - STEELSIM2021

The free grain sedimentation is a common transportation phenomenon in molten steel during the continuous casting process and has great effects on the solidification structure and defects of as-cast. Based on our previously proposed multi-scale cellular automaton model (CA-FVM), the free grain sedimentation in the continuously cast billet is numerical simulated and its effects on the solidification structure of wire steel 82b cast by a bow-type caster with section size of 160 mm×160 mm are quantitatively analyzed. The results show that under the effect of gravity, the free equiaxed grains, which form ahead of the columnar grain, would settle down and block the columnar grain in the outer arc of strand. But the free equiaxed grain would be gradually away from the columnar grain tip in the inner arc of strand and remelt in the strand core with high temperature. Thus, the mechanical block of free equiaxed grain on the growth of columnar grain becomes weaker in inner arc than that in outer arc of strand, and asymmetric morphology of solidification structure in continuously cast billet of 82b with casting speed of 1.8m/min is quantitatively determined that the length of the columnar grains in the inner arc and outer arc of strand are 57.0 mm and 31.0 mm respectively.