Abstract: In the mold powder, the content of F is 0.5% by mass or less (including 0% by mass), CaO and SiO2 are included as main components, the mass ratio of CaO to SiO2 (CaO/SiO2) is 0.6 to 1.4, the content of B2O3 is 0.3 to 2.8% by mass, the content of Na2O is 5.0 to 20.0% by mass, the total content of Li2O and K2O is 0 to 4.0% by mass, the content of MgO is 0 to 3.5% by mass, the content of Al2O3 is 1.0 to 8.0% by mass, and the content of MnO is 1.0% by mass or less (including 0% by mass).

Abstract: The cross-sectional shape of a flow passage 31 is circular in a first portion 3; the shape of a flow passage 51 is a flat shape in a second portion 5; in a connecting portion 4, the shape of a flow passage 41 is a shape continuously connecting the flow passage 31 of the first portion 3 and the flow passage 51 of the second portion 5; an opening 52 is provided on the distal end side of the second portion 5 and extends along a plane direction of the flat shape; and assuming that a maximum value of a cross-sectional area of the flow passage 31 in the first portion 3 is given by S1, that a maximum value of a cross-sectional area of the flow passage 51 in the second portion 5 is given by S2, and that a minimum value of a cross-sectional area of the flow passage 31 within a range of 20% of a length L1 of the first portion 3 from a boundary portion 42 between the first portion 3 and the connecting portion 4 toward the upstream side is given by S3, S2 is greater than S1, the ratio S1/S3 between S1 and S3 is 1.

Abstract: A gas injection nozzle refractory with one or more gas injection small metal tubes buried therein has improved durability. The gas injection nozzle refractory includes a MgO—C central refractory with a small metal tube buried therein, and a MgO—C peripheral refractory surrounding the central refractory. The central refractory on a plane of the gas injection nozzle refractory has an external shape of a circle with a radius in the range of R+10 to R+150 mm concentric with a virtual circle with a minimum radius surrounding all buried small metal tubes, R mm being a radius of the virtual circle.

Abstract: A submerged entry nozzle includes a bottomed cylinder having a vertical side face with at least two outlet ports and having an inner side and an outer side. The outlet port satisfies the following expressions: Vi/Vo?1.1??Expression (l) Ho/Hi?1.1??Expression (2) where Vi indicates a vertical opening dimension of each of the at least two outlet ports on the inner side, Hi indicates a horizontal opening dimension of each of the at least two outlet ports on the inner side, Vo indicates a vertical opening dimension of each of the at least two outlet ports on the outer side, and Ho indicates a horizontal opening dimension of each of the at least two outlet ports on the outer side.

Abstract: Disclosed herein is a mud material comprising a refractory raw material, an organic binder, and a curing agent, wherein part or all of the organic binder is a novolac-type phenol resin, part or all of the curing agent is a methylene donor, and wherein the methylene donor is at least one selected from the group consisting of hexa(methoxymethyl)melamine and hexamethoxymethylolmelamine.

Abstract: A gas injection nozzle refractory with one or more gas injection small metal tubes buried therein has improved durability. The gas injection nozzle refractory includes a MgO-C central refractory with a small metal tube buried therein, and a MgO-C peripheral refractory surrounding the central refractory. The central refractory on a plane of the gas injection nozzle refractory has an external shape of a circle with a radius in the range of R+10 to R+150 mm concentric with a virtual circle with a minimum radius surrounding all buried small metal tubes, R mm being a radius of the virtual circle.

Abstract: In the mold powder, the content of F is 0.5% by mass or less (including 0% by mass), CaO and SiO2 are included as main components, the mass ratio of CaO to SiO2 (CaO/SiO2) is 0.6 to 1.4, the content of B2O3 is 0.3 to 2.8% by mass, the content of Na2O is 5.0 to 20.0% by mass, the total content of Li2O and K,0 is 0 to 4.0% by mass, the content of MgO is 0 to 3.5% by mass, the content of Al2O3 is 1.0 to 8.0% by mass, and the content of MnO is 1.0% by mass or less (including 0% by mass).

Abstract: A method of producing an exothermic mold powder in a form of sprayed granules of the present invention includes spray-drying into granules, an aqueous slurry containing: a raw material blend; and a metal silicon powder and/or a silicon alloy powder, the method comprising adjusting the pH of the aqueous slurry to 13 or less.

Abstract: A method of producing an exothermic mold powder in a form of sprayed granules of the present invention includes spray-drying into granules, an aqueous slurry containing: a raw material blend; and a metal silicon powder and/or a silicon alloy powder, the method comprising adjusting the pH of the aqueous slurry to 13 or less.

Abstract: The apparatus for continuous slab casting having a nozzle exchanging-holding mechanism capable of moving a submerged nozzle at the exchange of the nozzle through a moving-connecting space D of a base under a slide valve mechanism and keeping the connection between the submerged nozzle and the slide valve mechanism during the operation, and a rotation mechanism to rotate the base of the nozzle exchanging-holding mechanism, which is characterized by a fixing mechanism that fixes the submerged nozzle in the nozzle exchanging-holding mechanism by pressing the submerged nozzle toward one or both inner sides of the moving-connecting space D of the base in one or both directions perpendicular to the moving direction of the submerged nozzle during the nozzle exchange.

Abstract: A slab continuous casting apparatus according to this invention is configured to supply molten metal from a tundish to a slab water-cooled mold through at least an upper nozzle, a stopper, and an immersion nozzle and solidify the molten metal, and is provided with an immersion nozzle quick replacement mechanism. The slab continuous casting apparatus includes a discharge direction change mechanism that is provided between the stopper and the immersion nozzle and is capable of freely changing a discharge angle of the molten metal in a horizontal cross-section during casting.

Abstract: The invention provides rotating a submerged nozzle during casting to arbitrarily change the discharge angle of molten metal, causing the molten metal in the mold for slab to be rotated and stirred. A slab continuous casting apparatus according to the invention supplies molten metal from a tundish to a water-cooled mold for slab through at least an upper nozzle, a slide valve and a submerged nozzle and solidified the molten metal and provided with a submerged-nozzle quick replacement mechanism. The slab continuous casting apparatus further includes a discharge-direction changing mechanism capable of arbitrarily changing discharge angle of the molten metal as viewed in a horizontal cross section, during casting, the discharge-direction changing mechanism being provided between a slide valve device for opening and closing the slide valve and the submerged nozzle.

Abstract: A submerged nozzle for continuous casting of molten metal, wherein two or more discharge hole flow passages are provided on a cylindrical side surface of a submerged nozzle, and first and second inner surface side walls and first and second outer surface side walls of the discharge hole flow passages in a horizontal cross-section of the submerged nozzle when in use are composed by straight lines formed so as to be inflected at an inner side point of inflection and an outer side point of inflection.

Abstract: A slide valve apparatus for automatic application of surface pressure is configured to include a connection switching device (20) for switching a connection position of a drive device (7) and a slide case (4) between a first connection position (discharge position) during molten metal discharge and a second connection position (surface pressure operation position) during surface pressure application/release. As a result, the drive stroke of the drive device can be greatly reduced and the already installed drive device can be used as is when a SV apparatus is upgraded.

Abstract: This invention relates to a gas blowing nozzle for blowing a gas to a molten metal in a furnace, the gas blowing nozzle including: a first nozzle section including a plurality of first narrow metal pipes having open furnace-side tips exposed to an inside of the furnace and being in the state of capable of blowing a gas to the molten metal in the furnace, a first surge tank communicated with the first narrow metal pipes, and a first refractory protecting the first narrow metal pipes and the first surge tank; and a second nozzle section including a plurality of second narrow metal pipes, a second surge tank communicated with the second narrow metal pipes, and a second refractory protecting the second narrow metal pipes and the second surge tank.

Abstract: A length from a lower end position of the detection head (11) to a measurement lower limit of the detection head (11) is divided by height positions separated with a predetermined interval pitch. A plurality of virtual level plates (40) are prepared to be placed respectively at the height positions separated with a predetermined interval pitch such that gaps between themselves and each wide face of the mold (1) are not larger than 2 mm respectively at the height positions. Calibration is carried out while using each of the virtual level plates (40) at a corresponding one of the height positions.

Abstract: In order to simplify work of applying and releasing a surface pressure in a slide valve device constructed of a fixed plate, a slide plate, a seal plate, and the like, provided is a slide valve device for automatic surface pressure application and a surface pressure application method therefor, the slide valve device including: a base frame (2) including a positioning member (51) for determining an arrangement location (X) of a seal case (21) and a stopper (52) for fixing the seal case (21) at the arrangement location (X); and a slide case (4) including a pusher (53) for sliding the seal case (21) together with the slide case (4) when sliding the slide case (4) in a surface pressure application direction.

Abstract: A submerged nozzle supporting-replacing mechanism, which is constituted to set an entire width dimension (L3) of each of clampers (20 and 21) to be smaller than a flange diameter dimension (L1) of a submerged nozzle (9) so as to position each of the clampers (20 and 21) by a positioning member (26), and so as to guide an upper surface (43) of a fresh submerged nozzle (9A) by a positioning liner (6), to thereby regulate a height position of the fresh submerged nozzle (9A) during movement in a horizontal direction thereof. The position of the clampers are regulated by setting the entire width dimension of the clampers to be smaller than the flange diameter dimension of the submerged nozzle, which can be smoothly replaced by providing the positioning liner.

Abstract: This invention relates to a gas blowing nozzle for blowing a gas to a molten metal in a furnace, the gas blowing nozzle including: a first nozzle section including a plurality of first narrow metal pipes having open furnace-side tips exposed to an inside of the furnace and being in the state of capable of blowing a gas to the molten metal in the furnace, a first surge tank communicated with the first narrow metal pipes, and a first refractory protecting the first narrow metal pipes and the first surge tank; and a second nozzle section including a plurality of second narrow metal pipes, a second surge tank communicated with the second narrow metal pipes, and a second refractory protecting the second narrow metal pipes and the second surge tank.

Abstract: A slide valve device for automatic surface pressure application including a slide valve having a three-layer structure, in which the movable bodies of the seal case is slidable on a support surface of a spring holder. The slide case and the seal case are coupled with each other by means of a coupling device or a coupling stopper, and the cases are slid together by means of an actuator so as to apply and release a surface pressure.