Reaction Between MnO-SiO₂-FeO Solid Oxide and Solid Steel Deoxidized by Si and Mn During Heat Treatment at 1473 K (1200 °C)

A new method using a confocal scanning laser microscope for melting oxide at 1673 K (1400 °C) to produce a diffusion couple, which consists of oxide and an iron-based alloy, has been developed for the investigation of a solid-state reaction between them. It is important to obtain good contact between the Fe-Mn-Si alloy and MnO-SiO₂-FeO oxide before the diffusion experiment to observe diffusion of elements between them at 1473 K (1200 °C). In this system, the melting point of the oxides is higher than the temperature where the reaction would be observed. The pretreatment involving melting oxide at 1673 K (1400 °C) to obtain good contact with the alloy was carried out using a new method. The effect of the pretreatment at 1673 K (1400 °C) on the diffusion experiment at 1473 K (1200 °C) was minimized by this new method. The effect of diffusion of oxygen on the solid-state reaction between the Fe-Mn-Si alloy and MnO-SiO₂-FeO oxide at 1473 K (1200 °C) was observed clearly and showed good agreement with Wagner’s model of internal oxidation of metal.