Research progress on functional MgO-C refractories for stopper rods in continuous casting tundishes

As a critical functional refractory component in continuous casting, the tundish stopper rod directly influences process continuity, molten steel cleanliness, and final product quality. Traditional Al₂O₃-C stopper rods face technical limitations—including chemical erosion, carbon oxidation, and insufficient high-temperature strength—when casting calcium-treated steels, high-manganese steels, and high-oxygen steels. This paper examines the performance advantages of MgO-C refractories as an alternative, focusing on their erosion-resistance mechanism and its effects on steel cleanliness and thermal shock resistance. Studies indicate that MgO-C materials inhibit the formation of low-melting-point phases due to the high melting point and low reactivity of MgO with steel components; a dense MgO reaction layer formed on the surface effectively blocks molten steel penetration; and the graphite component provides excellent thermal shock resistance and high-temperature structural stability. Furthermore, MgO-C materials help improve steel cleanliness by adsorbing inclusions such as Al₂O₃ and SiO₂ and mitigating carbon pickup. However, challenges remain for industrial application, including balancing carbon-free requirements with high performance, ensuring reliability in long-sized stopper rod structures, and controlling costs. Future efforts should promote wider adoption of MgO-C stopper rods in efficient continuous casting through multi-scale simulation, composite design, and process optimization.