Refractory material, continuous casting nozzle using the refractory material, production methods for the continuous casting nozzle, and continuous casting methods using the continuous casting nozzle

摘要

In an operation of continuous casting of steel grade such as aluminum-killed steel where a nozzle clogging phenomenon is particularly likely to occur, it is intended to prevent adhesion of inclusions (typically, Al₂O₃) on a nozzle used in the casting operation, and clogging of the nozzle due to the inclusions. A refractory material 10 is arranged to define a part or an entirety of a molten steel-contacting surface of a continuous casting nozzle, wherein the refractory material 10 contains: a CaO component in an amount of 0.5 mass % or more; one or both of B₂O₃ and R₂O (R is one selected from the group consisting of Na, K and Li) in an amount of 0.5 mass % or more; Al₂O₃ in an amount of 50 mass % or more; and free carbon in an amount of 8.0 to 34.5 mass %, and wherein a total amount of CaO, B₂O₃ and R₂O is in the range of 1.0 to 15.0 mass %, and a mass ratio of CaO/(B₂O₃+R₂O) is in the range of 0.1 to 3.0.