Abstract: Provided is a ZrO2—CaO—C based refractory material which is capable of maintaining high adhesion resistance over a long period of time, while exhibiting significant slaking resistance, and suppressing self-fluxing, i.e., exhibiting corrosion-erosion resistance. The refractory material comprises a CaO—ZrO2 composition containing a CaO component in an amount of 40% by mass to 60% by mass, wherein a mass ratio of the CaO component to a ZrO2 component is 0.67 to 1.5, and wherein the CaO—ZrO2 composition includes a eutectic microstructure of CaO crystals and CaZrO3 crystals, wherein a width of each of the CaO crystals observable in a cross-sectional microstructure is 50 ?m or less.

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: 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.

Abstract: A refractory product includes CaO component-containing refractory particles and MgO component-containing refractory particles. The refractory material contains, a chemical composition measured after it has undergone heating in a non-oxidizing atmosphere at 1000° C., one or more of the following metal oxides B2O3, TiO2, V2O5, P2O5 and SiO2 in a total amount of 0.1 to 5.0 mass %, and free carbon in an amount of 2 to 35 mass %, with the remainder including CaO and MgO whose mass ratio (CaO/MgO) is in the range of 0.1 to 1.5. In microscopic observation performed at room temperature on the refractory material which has undergone the above heating, an inorganic film comprised of CaO and the one or more metal oxides is formed in at least each CaO surface of the refractory particles each containing either one or both of a CaO component and an MgO component, with a thickness of 0.1 to 25 ?m.

Abstract: A refractory product includes CaO component-containing refractory particles and MgO component-containing refractory particles. The refractory material contains, a chemical composition measured after it has undergone heating in a non-oxidizing atmosphere at 1000° C., one or more of the following metal oxides B2O3, TiO2, V2O5, P2O5 and SiO2 in a total amount of 0.1 to 5.0 mass %, and free carbon in an amount of 2 to 35 mass %, with the remainder including CaO and MgO whose mass ratio (CaO/MgO) is in the range of 0.1 to 1.5. In microscopic observation performed at room temperature on the refractory material which has undergone the above heating, an inorganic film comprised of CaO and the one or more metal oxides is formed in at least each CaO surface of the refractory particles each containing either one or both of a CaO component and an MgO component, with a thickness of 0.1 to 25 ?m.

Abstract: 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.

Abstract: In a insert-type continuous casting nozzle comprising a highly functional layer formed to have a high corrosion resistance, a high anti-attachment capability, etc., and provided to define an inner bore thereof, the present invention is directed to providing a refractory material (mortar) for an intermediate layer of the continuous casting nozzle, which has a property capable of fixing an inner bore-side layer to an outer periphery-side layer (a nozzle body) of the continuous casting nozzle, while preventing the occurrence of expansion splitting in the outer periphery-side layer due to a difference in thermal expansion between the inner bore-side and outer periphery-side layers, and a continuous casting nozzle using the refractory material for the intermediate layer.

Abstract: [OBJECT] 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 [SOLUTION] 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.

Abstract: In a insert-type continuous casting nozzle comprising a highly functional layer formed to have a high corrosion resistance, a high anti-attachment capability, etc., and provided to define an inner bore thereof, the present invention is directed to providing a refractory material (mortar) for an intermediate layer of the continuous casting nozzle, which has a property capable of fixing an inner bore-side layer to an outer periphery-side layer (a nozzle body) of the continuous casting nozzle, while preventing the occurrence of expansion splitting in the outer periphery-side layer due to a difference in thermal expansion between the inner bore-side and outer periphery-side layers, and a continuous casting nozzle using the refractory material for the intermediate layer.

Abstract: Disclosed is a continuous casting nozzle, which comprises a layer formed to have high functions, such as high corrosion resistance and high anti-deposition capability, and disposed on the side of an inner bore thereof to serve as an inner bore-side layer, so as to enhance durability, wherein the continuous casting nozzle is capable of preventing expansion cracking of an outer periphery-side layer serving as a nozzle body thereof, due to a difference in thermal expansion between respective compositions of the inner bore-side layer and the outer periphery-side layer, while preventing peel-off of the inner bore-side layer during casting.