to loss of the matrix structure since ZrO2 particles are not enough to overlap together. When ZrO2 content is more than 20 vol%, the dense transition layer begins to form, and its thickness increases with increasing ZrO2 content [63].Without protective refractories addition, the h-BN and non-oxide are easily corroded by molten steel. ZrO2 are effective inhibitors for weakening corrosion process, which can inhibit the formation of protective layer between the bulk composite and molten steel. The corrosion rate is decelerated by the addition of ZrO2. Therefore, the addition of ZrO2 is beneficial to the decrease of corrosion rate, and improves the corrosion resistance by retarding the infiltration of dissolved oxygen into bulk composite. As are sult, h-BN-ZrO2-SiC composite ceramics have been considered as promising materials in metallurgical industry, especially directly contacting with molten steel as containment materials for continuous casting of steel.The corrosion mechanisms of h-BN matrix composite ceramics in molten steel are mainly proposed by slight dissolution and chemical reaction with dissolved oxygen. Recently, several physical and empirical models have been developed for corrosion processes of ceramic matrix composites. A general modeling can be made by assuming the simple linear and parabolic terms for corrosion process against molten steel. Chen et al. calculated the values of linear and parabolic rate constants of h-BN-ZrO2-SiC composites in molten steel at 1600◦C [63]. Kumar et al. further extend this idea by accounting for the corrosion depth in the radial direction with using the multi phase METSIM model in combination with FactSage to investigate interaction between molten steel and composites in N2 atmosphere [62]. The model prediction trends further con-firm that residual corrosion layer as inhibitor plays an active rolein the improvement of corrosion resistance by obstructing the further infiltration of molten steel. The components would come incontact with steel only through the formed pores, which slowed its dissolution and corrosion process.