Interfacial reaction between Al2O3-C refractory and Al killed steel

In the current investigation, the thin filmmethod was employed to clarify the formation mechanism of inclusions at the interface between refractory and liquid Fe. According to the electron probe micro-analysis (EPMA) mapping of the interface, a Si peak corresponding to SiO2 was significant at the interface between the refractory and Fe and a small amount of Fe oxide existed. A reacted layer was formed in a way that initially FeO enriched liquid layer was widely distributed on the Fe surface and FeO and SiO2 in the liquid layer were reduced by Al in liquid Fe to develop solid Al2O3 enriched layer of inclusions. Some inclusions in the liquid Fe might be produced by the remaining oxygen in Ar gas which was supplied through the nozzle to prevent the adherence of inclusions onto it. Thermodynamic prediction was carried out to confirm if the oxygen partial pressure with increasing the oxygen activity on Fe surface could closely be related to the formation of reacted layer.