In this study, to clarify the corrosion mechanism of CA6 based refractory by refining slag, the static crucible tests for CA6, CA6-Al2O3, and Al2O3 refractory, were carried out and the detail reaction processes were analyzed from the perspective of thermodynamic simulation and structural evolution. From the results, CaAl4O7 plays a vital role in the slag corrosion resistance of the three refractories. Regarding CA6 refractory, the double pyramid module in CA6 crystal structure was destroyed very quickly, leading to the rapid collapse of its structure to form the denser CaAl4O7 in high amounts. As a result, a reaction layer mainly composed of CaAl4O7 formed, which effectively inhibited the slag corrosion, so CA6 refractory exhibits the most excellent slag corrosion. Meanwhile, the formation of CaAl4O7 can also avoid CA6 particles entering the molten steel to introduce exogenous inclusions. For Al2O3 refractory, the generation of CaAl4O7 is much slower than that of CA6 and CA6-Al2O3 refractory, and the amount generated is also quite small, resulting in its worst slag corrosion among the three crucibles. Therefore, CA6 based refractory has excellent application potential in ladle refining and clean steel smelting.
Keywords: corrosion resistance; refining slag; refractory; thermodynamic simulation.