Abstract: A refractory material contains: 40 mass % or more of MgO; 4 to 30 mass % of a free carbon component; and one or more of B2O3, P2O5, SiO2 and TiO2, in a total amount of 0.3 to 3 mass %, with the remainder being at least one other type of additional refractory component. A void layer exists in an interface between a carbon-containing matrix microstructure residing at least on opposite sides of a maximum-size one of a plurality of MgO-containing particles in the refractory material, and the maximum-size MgO-containing particle. A sum of respective thicknesses of the void layer at two positions on the opposite sides is 0.2 to 3.0% of a ratio with respect to particle size of the maximum-size MgO-containing particle. An inorganic compound of MgO and the one or more of B2O3, P2O5, SiO2 and TiO2 exists entirety or partially in a surface of each of the MgO-containing particles.

Abstract: A refractory to be used repeatedly or for a long period of time, such as a refractory for casting, especially a nozzle for casting and an SN plate, has improved tolerance. The refractory for casting contains Al4O4C in the range of 15 to 60% by mass, both inclusive, an Al component as a metal in the range of 1.2 to 10.0% by mass, both inclusive, and a balance including Al2O3, a free C, and other refractory component; a sum of Al4O4C, Al2O3, and the Al component as a metal is 85% or more by mass; and a content of Al4O4C (Al4O4C), a content of the Al component as a metal (Al), and a content of the free carbon (C). The contact of the free carbon satisfies the following Equation 1 and Equation 2: 1.0?C/(Al4O4C×0.038+Al×0.33) (Equation 1) and 1.0?C/(Al4O4C×0.13+Al×0.67) (Equation 2).

Abstract: A refractory to be used repeatedly or for a long period of time, such as a refractory for casting, especially a nozzle for casting and an SN plate, has improved tolerance. The refractory for casting contains Al4O4C in the range of 15 to 60% by mass, both inclusive, an Al component as a metal in the range of 1.2 to 10.0% by mass, both inclusive, and a balance including Al2O3, a free C, and other refractory component; a sum of Al4O4C, Al2O3, and the Al component as a metal is 85% or more by mass; and a content of Al4O4C (Al4O4C), a content of the Al component as a metal (Al), and a content of the free carbon (C). The contact of the free carbon satisfies the following Equation 1 and Equation 2: 1.0?C/(Al4O4C×0.038+Al×0.33)??(Equation 1) and 1.0?C/(Al4O4C×0.13+Al×0.67)??(Equation 2).

Abstract: In order to suppress destruction of a refractory which contains a metal aluminum, the refractory is a refractory for steel casting which includes a refractory material containing a free carbon in the range of 1 to 10% by mass, both inclusive, a metal aluminum in the range of 1 to 15% by mass, both inclusive, and a metal oxide in a balance. The refractory for steel casting satisfies the following Equation 1: 0.31×Al?(P?4)/D (Equation 1), with a metal aluminum content in the refractory designated by Al % by mass, an apparent porosity thereof designated by P %, and a bulk density thereof designated by D.

Abstract: Provided is a refractory material having both excellent erosion/corrosion resistance and thermal shock resistance, which has hardly been obtainable by conventional techniques, and a casting nozzle using the refractory material. The refractory material of the present invention contains: MgO in an amount of 40 mass % or more; a free carbon component in an amount of 4 to 30 mass %; and one or more selected from the group consisting of B2O3, P2O5, SiO2 and TiO2, in a total amount of 0.3 to 3 mass %, with the remainder being at least one other type of additional refractory component, wherein a void layer exists in an interface between a carbon-containing matrix microstructure residing at least on opposite sides of a maximum-size one of a plurality of MgO-containing particles in the refractory material, and the maximum-size MgO-containing particle, wherein a sum of respective thicknesses of the void layer at two positions on the opposite sides is 0.2 to 3.