Abstract: Provided is a thermal spray material capable of, when used in a thermal spray operation for repairing a furnace wall of an industrial furnace or for other purposes, maintaining good post-repetition bondability with respect to a target surface to thereby prevent peel-off of a resulting thermally sprayed deposit, and improving initial ignitability while suppressing dust-generating property. The thermal spray material comprised a basic compound comprising at least one of a Ca component and an Mg component, a metal Si powder, and a silica-based or alumina-silica based powder. A content rate of a fraction constituting the basic compound and having a particle size of 0.15 mm or less is 30 mass % or more with respect to 100 mass % of the basic compound, and a content rate of a fraction constituting the metal Si powder and having a particle size of 20 ?m or less is from 10 mass % to 25 mass % with respect to 100 mass % of the thermal spray material.

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 address the technical problem of allowing an unshaped refractory material using a spinel-containing alumina cement to provide further improved corrosion resistance and slag infiltration resistance while reducing the occurrence of crack/peeling, an unshaped refractory material is provided which comprises a refractory raw material mixture having a particle size of 8 mm or less, with the refractory raw material mixture having an alumina cement at least a part of which is a spinel-containing alumina cement, and, with respect to 100 mass % of the refractory raw material mixture, the alumina cement contains CaO in an amount of 0.5 to 2.5 mass %, and the spinel-containing alumina cement contains spinel in an amount of 3.5 to 10.5 mass %.

Abstract: An immersion nozzle for use with an immersion nozzle replacement apparatus, capable of preventing crack formation due to the presence of a neck region. The immersion nozzle includes a nozzle body, a flange, and a metal casing. The nozzle body is formed such that a region of an outer peripheral surface thereof located above a point of power of an upward supporting force from a supporting device extends vertically up to an upper edge of the nozzle body without any dimensional change with respect to an central axis of an inner bore of the nozzle body. The outer peripheral surface region is not joined to the metal casing.

Abstract: In the present invention, the attempt was made to increase the denseness (to lower the porosity) of a magnesia carbon brick furthermore thereby providing the magnesia carbon brick having a high durability never found in the past. The magnesia carbon brick of the present invention comprises a magnesia raw material and a graphite, wherein the magnesia carbon brick contains the graphite with the amount thereof in the range of 8% or more by mass and 25% or less by mass and the magnesia raw material with the amount thereof in the range of 75% or more by mass and 92% or less by mass, the both amounts being relative to the total amount of the magnesia raw material and the graphite; as a grain size distribution of the magnesia raw material, the magnesia raw material having particle diameter of in the range of 0.

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: Disclosed is a technique for suppressing a firing property and a dust generating property while improving bondability, in a thermal spray material for use in a thermite spraying process. The thermal spray material comprises a refractory material powder and a metal Si powder and capable of being sprayed onto a target surface using oxygen or oxygen-containing gas as a carrier gas and melt-adhered to the target surface based on heat generated by combustion of the metal Si powder, wherein the metal Si powder is contained in an amount of 10 to 25 mass % with respect to the entire thermal spray material, and wherein the metal Si powder has a median size of 10 ?m or less, and contains a fraction having a particle size of 2 ?m or less in an amount of 8 mass % or less with respect to the entire metal Si powder.

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 the present invention, the attempt was made to increase the denseness (to lower the porosity) of a magnesia carbon brick furthermore thereby providing the magnesia carbon brick having a high durability never found in the past. The magnesia carbon brick of the present invention comprises a magnesia raw material and a graphite, wherein the magnesia carbon brick contains the graphite with the amount thereof in the range of 8% or more by mass and 25% or less by mass and the magnesia raw material with the amount thereof in the range of 75% or more by mass and 92% or less by mass, the both amounts being relative to the total amount of the magnesia raw material and the graphite; as a grain size distribution of the magnesia raw material, the magnesia raw material having particle diameter of in the range of 0.

Abstract: The invention provides a plate-fixing structure designed for use with a sliding nozzle device to fix a plate to a plate-receiving metal frame. The plate-fixing structure is usable in a concavo-convex fitting technique with respect to fitting a convex or concave portion of a plate to a corresponding convex or concave portion of a plate-receiving metal frame to easily achieve alignment between the convex or concave portion of the plate and the corresponding convex or concave portion of the plate-receiving metal frame. A plate for use with the plate-fixing structure is also provided.

Abstract: With a view to adding, to an upper nozzle formed with a bore having a shape capable of creating a less energy loss or smooth (constant) molten steel flow to suppress the occurrence of adhesion of inclusions and metals in molten steel, a gas injection function to thereby further suppress the occurrence of the adhesion, the present invention provides a method of using an upper nozzle configured to have a cross-sectional shape of a wall surface defining the bore, taken along an axis of the bore, comprising a curve represented by the following formula: log(r (z))=(1/n)×log((H+L)/(H+z))+log(r (L)) (n=1.5 to 6), where: L is a length of the upper nozzle; H is a calculational hydrostatic head height; and r (z) is an inner radius of the bore at a position downwardly away from an upper edge of the bore by a distance z. The method comprises using the upper nozzle in such a manner as to satisfy the following relationship: RG?4.

Abstract: The present invention provides an SN plate capable of being formed in a large size while using a highly corrosion resistant and highly thermally expansible refractory product. In the SN plate of the present invention, a specific refractory member 1a having a thermal expansion rate as measured at 1500° C. of 1.15 to 2.50% due to addition of aluminum for improving corrosion resistance is arranged as a part of the SN plate to cover at least a practically critical region of the SN plate. A thickness of the specific refractory member is set in a range of 15 to 25 mm. A portion of the SN plate other than the specific refractory member is made up of an unburned or burned refractory product consisting primarily of an alumina-carbon composite.

Abstract: Disclosed is a boron carbide-based ceramics material which has a high density and a high specific rigidity, but additionally with excellent processability, and a production method for the boron carbide-based ceramics material. Specifically, the high-rigidity ceramics material contains boron carbide in an amount of 90 to 99.5 mass %, wherein at least silicon, aluminum, oxygen and nitrogen coexist in a grain boundary phase between crystal grains of the boron carbide. This high-rigidity ceramics material can be produced by a method comprising: preparing a boron carbide powder, and, as a sintering aid, one or more selected from the group consisting of an oxide, a nitride and an oxynitride of silicon, an oxide, a nitride and an oxynitride of aluminum, and a composite oxide, a composite nitride and a composite oxynitride of aluminum and silicon, in such a manner as to contain all of Si, Al, O and N; and subjecting the boron carbide powder and the sintering aid to mixing, forming and sintering.

Abstract: Provided is a plate fixing structure which is usable in a concavo-convex fitting technique for fitting with respect to a fitting concave or convex portion provided in a plate-receiving metal frame, and capable of easily achieving an alignment between the fitting convex portion and the fitting concave portion, and a plate for use with the fixing structure. The plate 10 is provided with a first engagement portion 14 extending from one of opposite ends thereof in a sliding direction thereof, and a second engagement portion extending from the other end, and the plate-receiving metal frame 20 is provided with a first support portion 22 and a second support portion 23 each configured to allow a respective one of the first engagement portion 14 and the second engagement portion 15 to be engaged therewith.

Abstract: It is an object to provide an aluminum oxycarbide composition capable of suppressing oxidation of Al4O4C during use to maintain advantageous effects of Al4O4C for a long time. In an aluminum oxycarbide composition comprising Al4O4C crystals, the Al4O4C crystals have an average diameter of 20 ?m or more, based on an assumption that a cross-sectional area of each Al4O4C crystal during observation of the aluminum oxycarbide composition in an arbitrary cross-section thereof is converted into a diameter of a circle having the same area as the cross-sectional area. This aluminum oxycarbide composition can be produced by subjecting a carbon-based raw material and an alumina-based raw material to melting in an arc furnace and then cooling within the arc furnace.

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: Disclosed is a method of producing a plate brick, which comprises: adding an organic binder to a refractory raw material mixture containing aluminum and/or an aluminum alloy; kneading them; forming the kneaded mixture into a shaped body; and burning the shaped body in a nitrogen gas atmosphere at a temperature of 1000 to 1400° C., wherein: when a temperature of a furnace atmosphere is 300° C. or more, the atmosphere is set to a nitrogen gas atmosphere; and when the temperature of the furnace atmosphere is 1000° C. or more, an oxygen gas concentration in the atmosphere is maintained at 100 volume ppm or less, and a sum of a carbon monoxide gas concentration and a carbon dioxide gas concentration is maintained at 1.0 volume % or less.

Abstract: Disclosed is a sliding nozzle plate (composite sliding nozzle plate) (2) for use in a sliding nozzle device for adjusting an outflow amount of molten metal from a molten metal vessel. The sliding nozzle plate (2) comprises a sliding nozzle plate body and a tubular member (3) formed with a flange (3a) and attached to a bore (through-hole (1c?)) of the sliding nozzle plate body, and satisfies the following conditional formulas (1) and (2): ?B??I?5??(1); and ?B??R?4??(2), where: ?B is a diameter (mm) of the bore of the sliding nozzle plate body; ?I is an outer diameter (mm) of the flange of the tubular member; and ?R is an outer diameter (mm) of the non-flange portion of the tubular member. The composite sliding nozzle plate is capable of preventing displacement of the tubular member and molten metal penetration into a joint between the tubular member and the sliding nozzle plate body.

Abstract: Disclosed is a boron carbide-based ceramics material which has a high density and a high specific rigidity, but additionally with excellent processability, and a production method for the boron carbide-based ceramics material. Specifically, the high-rigidity ceramics material contains boron carbide in an amount of 90 to 99.5 mass %, wherein at least silicon, aluminum, oxygen and nitrogen coexist in a grain boundary phase between crystal grains of the boron carbide. This high-rigidity ceramics material can be produced by a method comprising: preparing a boron carbide powder, and, as a sintering aid, one or more selected from the group consisting of an oxide, a nitride and an oxynitride of silicon, an oxide, a nitride and an oxynitride of aluminum, and a composite oxide, a composite nitride and a composite oxynitride of aluminum and silicon, in such a manner as to contain all of Si, Al, O and N; and subjecting the boron carbide powder and the sintering aid to mixing, forming and sintering.