Interfacial reaction between Al 2 O 3 –C refractory and Al killed steel

Abstract

In the current investigation, the thin film method 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.