Fine equiaxed dendritic structure of a medium carbon steel cast using pulsed magneto-oscillation melt treatment

Abstract

The application of a pulsed magneto-oscillation (PMO) technique during the solidification of a commercial high melting point medium carbon steel ingot (φ140 mm × 450 mm) produced fully equiaxed grains in the cast ingot, indicating that the PMO process significantly promotes heterogeneous nucleation near the solid-liquid interface. The vigorous convection induced by PMO forced the partly solidified grains to move from the solid-liquid interface and became randomly distributed throughout the melt, which resulted in the formation of uniformly sized equiaxed dendrites throughout the whole ingot. Building on the developed nucleation mechanism and a flow field simulation of pure aluminum, a PMO-induced grain refinement model for steel is proposed.