Influence of crucible material on inclusions in 95Cr saw-wire steel deoxidized by Si–Mn

To investigate the interaction mechanism between 95Cr saw-wire steel and different refractories, we conducted laboratory experiments at 1873 K. Five crucible materials (SiO₂, Al₂O₃, MgO·Al₂O₃, MgO, and MgO–CaO) were used. The results indicate that SiO₂, Al₂O₃, and MgO·Al₂O₃ are not suitable for smelting low-oxygen, low-Al_s 95Cr saw-wire steel, mainly because they react with the elements in the molten steel and pollute the steel samples. By contrast, MgO–CaO is an ideal choice to produce 95Cr saw-wire steel. It offers three advantages: (i) It does not decompose by itself at the steelmaking temperature of 1873 K because it exhibits good thermal stability; (ii) C, Si, and Mn in molten steel cannot react with it to increase the O content; and (iii) it not only desulfurizes and dephosphorizes but also removes Al₂O₃ inclusions from the steel simultaneously. As a result, the contents of the main elements (C, Si, Mn, Cr, N, T.O (total oxygen)) in the steel are not affected and the content of impurity elements (Al_s, P, and S) can be perfectly controlled within the target range. Furthermore, the number and size of inclusions in the steel samples decrease sharply when the MgO–CaO crucible is used.