The Mechanism of Inhibiting the Adsorption of Rare-Earth Inclusions in Molten Steel by Al2O3, YAlO3 and Y2O3 Refractory by Impressed Current

The adsorption of rare-earth Y-based inclusions (Y, Y2O3, Y2O2S) on Al2O3, YAlO3, and Y2O3 refractory surfaces is a primary cause of nozzle clogging during the continuous casting of rare-earth steels. Conventional anti-clogging strategies, being passive and offline, lack real-time adjustability. This study aims to elucidate the mechanism by which external positive charge modulates interfacial adsorption. Using first-principles calculations combined with partial density of states, charge density difference, and thermodynamic analyses, we investigated the adsorption behavior of Y, Y2O3, and Y2O2S on Al2O3 (001), YAlO3 (001), and Y2O3 (001) surfaces under neutral and positively charged states (+2, +4). A triple inhibition mechanism is revealed: electronically, external charge disrupts O-p and Y-d orbital hybridization, attenuating interfacial covalent bonding; electrostatically, the net positive charge shifts the interfacial interaction from attraction to repulsion, creating a physical barrier; and thermodynamically, the Gibbs free energy change ΔG increases under charged conditions, indicating a quantifiable reduction in adsorption spontaneity. These findings provide a theoretical basis for the development of active anti-clogging strategies in rare-earth steel production.