We analyze the erosion mechanism of magnesia carbon bricks from the aspects of slag, carbon content and carbon structure in magnesia-carbon bricks, raw materials of magnesia-carbon bricks, and additives in MgO-C Brick, and get the erosion of magnesia-carbon bricks. The damage process mainly includes the following: oxidation-decarburization-porosity-erosion-erosion-shedding-damage. In this process, due to the oxidative removal of carbon, the brick structure becomes loose and brittle, and it is worn out under the erosion of molten steel. At the same time, due to the oxidative removal of carbon and the loose brick body, the slag penetrates into the decarburized layer, and Reacts with magnesia particles.
1. Erosion of refined slag
The ladle undergoes LF and VD refining treatment, and is affected by arc light, vacuum and steel slag erosion, which accelerates the erosion of the slag line. Calcium oxide, silicon dioxide and other substances in the slag chemically react with the refractory bricks, forming a slag penetration layer on the surface of the magnesia carbon brick, causing discontinuous damage to the inner lining. Both iron oxide and iron trioxide in low alkalinity slag will corrode refractory materials.
2. High temperature vacuum accelerates the damage of MgO-C Bricks
Magnesia carbon bricks will accelerate volatilization under high temperature and vacuum. The weight loss caused by vacuum degassing reduces the strength and softness of refractory materials and accelerates the corrosion of MgO-C Brick.
3. In the production process, the temperature of the steel is low, and the temperature is greatly increased during refining, so that the temperature of the slag near the electrode is too high, and the slag line is just at the far ends of the permeable brick, which is a dead zone of circulation, and the slag temperature is timely without slag. Transmission, causing erosion of the slag line at the arc point.