CORROSION OF MAGNESIA CARBON REFRACTORY AT STEEL-SLAG BOUNDARY DURING ORIENTED SILICON STEELMAKING

摘要

The corrosion process of MgO-C refractory with different graphite content at the steel-slag boundary during oriented silicon steelmaking were investigated via dynamic experiment combined with electron probe microanalysis with energy disperses spectroscopy (EDAS) and chemical analysis. Thermodynamic analysis were performed to assist understanding the related processes. The experiment is done via induction furnace with Ar atmosphere protection , the MgO-C mixes were fabricated into crucible shape by isostatic presser under 200 MPa first and then it was placed into induction furnace with oriented silicon steel, the refining slag was added into the crucible sooner after the steel was melt. The experiment is done at 1600°C for 2 hours.The corrosion of MgO-C refractory at steel-slag boundary is severe under dynamic experiment. The graphite and periclase of refractories dissolve into steel melt and deteriorates the integrity of the refractory and results in corrosion. It can be concluded from the results that the carbon content in MgO-C brick should be controlled to a certain amount to reach a balance among slag resistance, thermal shock resistance and the effect of carbon oxidation and solution loss on integrity of MgO-C refractory.