Effect of Al content on the reaction between Fe−10Mn−xAl (x = 0.035wt%, 0.5wt%, 1wt%, and 2wt%) steel and CaO−SiO₂−Al₂O₃−MgO slag

The effect of Al content (0.035wt%, 0.5wt%, 1wt%, and 2wt%) on the composition change of steel and slag as well as inclusion transformation of high manganese steel after it has equilibrated with CaO−SiO₂−Al₂O₃−MgO slag was studied using the method of slag/steel reaction. The experimental results showed that as the initial content of Al increased from 0.035wt% to 2wt%, Al gradually replaced Mn to react with SiO₂ in slag to avoid the loss of Mn due to the reaction; this process caused both Al₂O₃ in slag and Si in steel to increase while SiO₂ and MnO in slag to reduce. In addition, the type of inclusions also evolved as the initial Al content increased. The evolution route of inclusions was MnO → MnO−Al₂O₃−MgO → MgO → MnO−CaO−Al₂O₃−MgO and MnO−CaO−MgO. The shape of inclusions evolved from spherical to irregular, became faceted, and finally transformed to spherical. The average size of inclusions presented a trend that was increasing first and then decreasing. The transformation mechanism of inclusions was explored. As the initial content of Al increased, Mg and Ca were reduced from top slag into molten steel in sequence, which consequently caused the transformation of inclusions.