Dynamic interaction between refractory and low-carbon low-silicon Al-killed steel

To investigate the dynamic interaction between refining refractory and low-carbon low-silicon Al-killed steel, the "refractory-molten steel-inclusion" system was analyzed using dynamic erosion experiments and the FactSage database. This study discussed the formation of interfacial layers between various refining refractories and molten steel, as well as the transformation of nonmetallic inclusions in steel. The findings indicate that the interaction between refractories and molten steel produces a distinct interface layer. The influence of various refining refractories on inclusions varies significantly. MgO-C refractory promotes the formation of MgO<middle dot>Al2O3 inclusions in steel, while Al2O3-MgO refractory leads to the formation of SiO2-MnO-Al2O3 inclusions. Both Al2O3-SiC refractory and Al2O3-MgO-C refractory result in Al2O3 inclusions with trace levels of MgO. Steel refined with Al2O3-MgO-C refractory has increased MgO content within Al2O3 inclusions but still does not reach the stoichiometric ratio of MgO<middle dot>Al2O3. As the initial Al content increases, the influence of MgO-C refractory inclusions becomes increasingly noticeable. The average MgO content within the inclusions rises with the reaction duration, achieving as high as 62.9%. The transition path of Al2O3 inclusions in molten steel follows "Al2O3 -> MgO<middle dot>Al2O3 -> MgO."