Magnesia carbon brick has the advantages of high temperature resistance, good slag resistance, strong thermal shock resistance, high thermal conductivity and low high temperature creep, so it is widely used in steelmaking production. In the ladle refining process, the erosion of the slag line magnesia carbon brick is usually the most severely damaged area of ​​the lining. The long-term chemical erosion and mechanical erosion of the slag become the main damage mechanism. Damage is an important factor affecting production efficiency and production costs. The wettability between molten slag and refractory is one of the important indexes to measure the resistance of refractory to slag erosion and penetration.

Scholars from the University of Science and Technology Beijing used the sessile drop method to measure the contact angle between solid and liquid. They studied the wettability between the magnesium-carbon substrate and the two main components of the substrate and the LF refining slag, and studied the wettability The damage mechanism of magnesia-carbon bricks was studied from a sexual perspective. Studies have shown that at the refining temperature, the molten slag is in a non-wetting state for graphite, and the lower the temperature, the less likely it is to wet. The molten slag is completely wetted to the MgO component. The contact angle between the slag and the magnesium carbon substrate has a significant turning point when the temperature is 1460-1480°C. Below the turning point temperature, the reaction of MgO and carbon is inhibited, and the slag keeps the substrate in a non-wetting state. Above the turning point temperature, MgO and carbon in the magnesium-carbon substrate react to generate magnesium vapor and CO gas. This reaction leads to a decrease in the carbon mass fraction in the substrate, and the contact angle of the slag to the substrate decreases rapidly, and finally it is completely wetted. When the contact angle between the slag and the substrate is less than 90°, the slag will significantly penetrate the substrate. The pores formed by the reaction of MgO and carbon become the main channel for slag penetration. When the slag penetrates into the unreacted layer inside the magnesium-carbon substrate, the non-wettability between the two and the less porosity prevent further penetration of the slag.