Abstract: In view of stopper rod abnormal erosion of SAE series low-carbon and low-alloy steel during casting process, stopper rod erosion mechanism and corresponding improvement measures were proposed through phase analysis and element distribution. The results show that the high carbon component in stopper rod reacts with the oxygen in molten steel to form a decarburized layer on the surface of stopper rod. The inclusions with high Si_O2 component in molten steel adhere to the surface of stopper rod, react with MgO, MgO·Al₂O₃, and form low melting point phase of Mg₂SiO₄ type, which is brought into molten steel under the action of molten steel, causing corrosion of stopper rod. The abnormal corrosion of stopper rod was significantly improved by selecting stopper rod with low carbon, high density and appropriate amount of SiC, increasing basicity of slag and reducing oxygen content in molten steel, and the number of tundish continuous casting furnaces increased from 8-10 furnaces to more than 15 furnaces.

Key words: low-carbon and low-alloy steel, corrosion mechanism of stopper rod, molten steel castability