Abstract: A method of and an apparatus for controlling a molten metal surface in a mold that are effective to various disturbances are provided. The method and the apparatus for controlling a molten metal surface level in a mold according to the present invention perform the following operations of: measuring the molten metal surface level in the mold of a continuous-casting machine; changing a reference position of oscillation of the mold based on the difference between a molten metal surface setting value set in advance as a desired value of the molten metal surface and a measured value of the molten metal surface level; and making the reference position of oscillation follow molten metal surface fluctuations.

Abstract: A roller leveler for flattening a metal sheet or plate having a cut-sheet form includes leveling rolls disposed in a staggered state on upper and lower sides of a pass line and configured to sandwich and flatten the metal sheet while pressing it therethrough, a hydraulic pressing cylinder for pressing the metal sheet via the leveling rolls, intermediate rolls set in contact with the respective leveling rolls from outside and larger in diameter than the leveling rolls, and a drive unit for rotating the intermediate rolls. The roller leveler causes the drive unit to rotate the intermediate rolls and transmits the driving force to the leveling rolls to pass the metal sheet while causing the pressing cylinder to press the metal sheet via the leveling rolls.

Abstract: A roller leveler for flattening a metal sheet or plate having a cut-sheet form includes leveling rolls disposed in a staggered state on upper and lower sides of a pass line and configured to sandwich and flatten the metal sheet while pressing it therethrough, a hydraulic pressing cylinder configured to press the metal sheet via the leveling rolls, a drive unit configured to rotate the leveling rolls, and a pinch roll unit disposed on one side of a leveling roll array area and including a pair of pinch rolls. The pressing cylinder presses the metal sheet via the leveling rolls with a pressing amount necessary for flattening the metal sheet, while the metal sheet is passed by a drawing force applied by the pinch rolls and a driving force applied by the drive unit.

Abstract: A welder for a metal rolling system, which is disposed in the metal rolling system and is configured to perform spot-welding on a product strip, includes a back bar disposed below the pass line and welding guns disposed above the pass line to perform series welding for welding a plurality of points at one time.

Abstract: The continuous rolling method and the continuous rolling apparatus provide good product quality and product yield by successively joining pluralities of traveling hot steel pieces by flash welding, and by rolling thus prepared endless steel piece, thus preventing generation of flaws in the rolling step, thereby manufacture steel rods, wires, and the like by the continuous rolling technology. The method has: a heating step for heating billet to a specified temperature; a flash welding step for joining the trailing end of preceding billet with the leading end of succeeding billet while they are traveling using flash welding; a deburring step for removing burrs from the welded part; a trimming step for trimming corners of cross section of the deburred welded part; and a rolling step for rolling the joined billets.

Abstract: A waste heat recovery structure includes a first exhaust gas flow path provided to each of steel making electric arc furnaces to discharge exhaust gas thereinto; a waste heat boiler disposed on the first exhaust gas flow path to recover waste heat as saturated steam from exhaust gas; a steam accumulator configured to store steam formed by confluence of saturated steam parts, each generated by the waste heat boiler; a steam super heater configured to turn steam into superheated steam by heating; a second exhaust gas flow path configured to lead exhaust gas from the waste heat boiler to the steam super heater to use it for superheating; a third exhaust gas flow path configured to discharge exhaust gas from the waste heat boiler not through the steam super heater; and a switching device configured to switch flow paths between the second and third exhaust gas flow paths.

Abstract: A pusher includes a pusher main body configured to push forward a target object; a pusher main body cylinder connected to the pusher main body and configured to move the pusher main body forward and backward; a pusher carriage connected to the pusher main body cylinder; and a pusher carriage cylinder connected to the pusher carriage and configured to move the pusher carriage forward and backward, the pusher carriage cylinder having a pushing-out direction opposite to a pushing-out direction of the pusher main body cylinder.

Abstract: A system for transporting red-hot coke including a non-rotary coke receiving car which travels on a first rail for receiving coke from at least one coke oven chamber; at least two rotary coke buckets, the at least two rotary coke buckets being mounted on a turntable, wherein the turntable is operable to orbit the at least two rotary coke buckets around its center, and the turntable travels along a second rail; one or two sets of discharge devices, each containing a discharge chute and a dust collector hood, which is operable to discharge the coke from the non-rotary coke receiving car to the at least two rotary coke buckets; and a hoist for hoisting and transporting the at least two rotary coke buckets to a coke dry quenching unit.

Abstract: Equipment and a method for transporting red-hot coke are provided, which do not need increase in size of a hoist, reinforcement of a CDQ system, and the like, even when the amount capacity of a coke bucket does not correspond to an amount equivalent to the coke amount from one oven chamber. In particular, transporting equipment for red-hot coke, includes: a non-rotary coke receiving car for receiving coke out of a coke oven; a coke bucket for receiving the coke discharged from the coke receiving car; a transporting device for transporting the coke bucket to a hoist position; and a hoist for transporting the coke bucket to a coke dry quenching system.

Abstract: An electric arc melting facility includes a melting chamber configured to melt a source iron therein by electric arc discharge generated from an electrode, and a source iron feeder configured to continuously feed the source iron to the melting chamber. The facility further includes a state change detector configured to detect a state change of the melting chamber when the electric arc discharge is generated from the electrode, and a controller configured to adjust a feed rate at which the source iron feeder feeds the source iron to the melting chamber, based on a detection result of the state change detectors.

Abstract: [PROBLEMS] To provide a roll, a rolling mill and rolling method capable of not only effectively correcting the plate crown of a material to be rolled but also reducing the edge drop and preventing a roll from damage caused by the increase of the local line pressure between the rolls. [MEANS FOR SOLVING PROBLEMS] A roll crown is formed by a continuous curve having a local maximum point and a local minimum value point where the central region held between the local maximum point and the local minimum point represents one function and the end region from the local maximum point to the nearer roll end represents another function having an inclination of steeper gradient (or having a radius decreasing more sharply toward the roll end) than that of the extension of the function in the central region.

Abstract: An electric arc melting facility includes a melting chamber configured to melt a source iron therein by an electrode, and a shaft-shaped preheating chamber directly connected to the melting chamber. The preheating chamber includes a bottom surface inclined downward toward the melting chamber. A shaft opening dimension is set to an optimum value for controlling the supply of the source iron. A pushing device is disposed at a lower side of the preheating chamber and configured to move the source iron toward the melting chamber. The supply of the source iron from the preheating chamber to the melting chamber is performed by operating the pushing device. The supply of the source iron from the preheating chamber to the melting chamber is stopped by halting the operation of the pushing device.

Abstract: A roller leveler is provided having a substantially uniform pitch of leveling rolls arranged in a zigzag manner. The roller leveler is provided with a first roll group having first leveling rolls arranged with a pitch “P1” in the carrying direction of a steel plate, a second roll group having five pieces of second leveling rolls which are arranged with the pitch “P1” in the carrying direction of the steel plate and have a zigzag arrangement with respect to the first leveling rolls, a first retract mechanism for retracting the middle first leveling rolls from the pass line, and second retract mechanisms for retracting the pairs of end second leveling rolls from the pass line. The second roll group has third leveling rolls disposed with the pitch “P1” in the carrying direction of the steel plate with respect to the outermost second leveling rolls.

Abstract: An air supply apparatus includes a plurality of movable carriages arranged along a circular carriage path; a movable circular duct arranged along the carriage path and connected to each of the carriages through a connection air duct; a water sealing device including a circular water seal chamber arranged along the carriage path and a water sealing plate having a lower end part thereof sunk in sealing water in the circular water seal chamber; a stationary circular duct arranged along the carriage path and fitted into the movable circular duct through the water sealing device to be freely movable, wherein the movable circular duct and the stationary circular duct form a circular air path; and an atmospheric zone that stops leakage of air in the carriage being provided in a predetermined position of the carriage path, wherein an upper space of the circular water seal chamber on a circular air path side communicates with the circular air path on a movable circular duct side, the circular air path on the movable c

Abstract: Equipment and a method for transporting red-hot coke are provided, which do not need increase in size of a hoist, reinforcement of a CDQ system, and the like, even when the amount capacity of a coke bucket does not correspond to an amount equivalent to the coke amount from one oven chamber. In particular, transporting equipment for red-hot coke, includes: a non-rotary coke receiving car for receiving coke out of a coke oven; a coke bucket for receiving the coke discharged from the coke receiving car; a transporting device for transporting the coke bucket to a hoist position; and a hoist for transporting the coke bucket to a coke dry quenching system.

Abstract: To provide a roll, a rolling mill and rolling method capable of not only effectively correcting the plate crown of a material to be rolled but also reducing the edge drop and preventing a roll from damage caused by the increase of the local line pressure between the rolls. A roll crown is formed by a continuous curve having a local maximum point and a local minimum value point where the central region held between the local maximum point and the local minimum point represents one function and the end region from the local maximum point to the nearer roll end represents another function having an inclination of steeper gradient (or having a radius decreasing more sharply toward the roll end) than that of the extension of the function in the central region.

Abstract: The continuous rolling method and the continuous rolling apparatus provide good product quality and product yield by successively joining pluralities of traveling hot steel pieces by flash welding, and by rolling thus prepared endless steel piece, thus preventing generation of flaws in the rolling step, thereby manufacture steel rods, wires, and the like by the continuous rolling technology. The method has: a heating step for heating billet to a specified temperature; a flash welding step for joining the trailing end of preceding billet with the leading end of succeeding billet while they are traveling using flash welding; a deburring step for removing burrs from the welded part; a trimming step for trimming corners of cross section of the deburred welded part; and a rolling step for rolling the joined billets.

Abstract: An indirect heating furnace heats a substance in a reaction tube with a high-temperature combustion gas without contact between the substance and the combustion gas. The reaction tube is a stationary ceramic tube. A combustion device for supplying said heating high-temperature combustion gas into the furnace in comprised of at least one pair of regenerative burners.

Abstract: The present invention provides an arc-melting apparatus which attains extremely high efficiency by preheating scraps using exhaust gas from the melting chamber. The arc-melting apparatus needs for no device to carry and supply an iron source to a melting chamber, which makes it possible to preheat the next charge. The arc-melting apparatus has a melting furnace which melts scraps, a preheating shaft connected directly to an upper part of one side of the melting furnace, an arc electrode for melting scraps in the melting furnace, a bucket for supplying scraps to the preheat shaft so as to continuously maintain scraps in the melting furnace and in the preheating shaft, a tapping portion having a tapping hole, being projected outward from the melting furnace and a tilting device for tilting the melting furnace on a side of the tapping portion. The tapping portion is arranged at an orthogonal direction to the direction of the supplied cold iron source.

Abstract: A burr located at an edge of a steel piece is cut by disposing a cutter such that the flank of the cutter is substantially in parallel with the surface of the steel piece and the angle between the cutting edge of the cutter and the edge of the steel piece which the burr intersects is at least 45°. The cutter is relatively moved toward the outside of the steel piece along the lengthwise direction of the burr, or the cutter is disposed with the flank of the cutter substantially in parallel with the surface of the steel piece and the angle between the cutting edge of the cutter and the edge of the steel piece is at least 90°. The burr located at the edge of the steel piece is cut by relatively moving the cutter perpendicularly to the lengthwise direction of the burr.