Interface reaction between novel microporous magnesia refractory and H13 steel: understanding purification mechanism
摘要
High-quality steel production requires superior-performance refractories. To meet the requirements of quality enhancement and efficiency improvement in the steelmaking industry, the application of the novel microporous magnesia with high strength, remarkable slag resistance, and excellent thermal insulation is promoted. The interface reaction between H13 steel and novel microporous magnesia castable was investigated by using the crucible method, to elucidate the molten steel purification mechanism. The interface microstructure was observed by scanning electron microscopy, and the composition, size, and amount of inclusions were statistically analyzed. A thermal calculation was conducted to gain a deeper understanding of the modification process of inclusions. Fused magnesia castables were used as the blank control. The results show that the average number density and size of inclusions were reduced by 5.99 mm−2 and 0.28 μm respectively after the same reaction time because the micropores enhanced the inclusion adsorption. The size of inclusions caused by erosion decreased. Also, more [Mg] dissolved into molten steel over 60 min reaction time and resulted in a 0.49 wt.% increase in inclusion Mg content, which modified the inclusion by decreasing their melting point. Therefore, applying novel microporous magnesia was beneficial for purifying H13 steel.