Numerical Simulation of the Solidification Microstructure of Fe-3.0 Pct Non-oriented Silicon Steel Ribbons Prepared by Planar Flow Casting

A mathematical model based on the macroscopic finite element method coupling with micro-cellular automata is employed to simulate and analyze the macroscopic fluid flow, heat transfer, and solidification behavior, as well as microstructural variations in the planar flow casting process. It is found that, at the macroscopic level, the melt is injected from the nozzle to the cooling wheel, forming a melt puddle that gradually reaches its steady state. The solid-liquid mixed layer along the solidification front is very thin, and the solidification process is carried out in a laminar manner, which is favorable to the realization of sequential solidification and obtaining a ribbon with a dense microstructure. At the microscopic level, the microstructure of the ribbon produced by planar flow casting consists of equiaxed grains near the wheel surface and columnar grains oriented normally to the surface of the cooling wheel. Increasing both the melt superheat and the melt injection velocity results in an increase in grain size and the proportion of columnar grains, a decrease in the grain misorientation angle, and a smaller grain misorientation angle. Increasing the heat transfer coefficient and the cooling wheel speed will decrease grain size, reduce the proportion of columnar grains, and increase the grain misorientation angle.