Abstract: A shear device (21) of an extrusion press having a booster mechanism using an air cylinder or electric motor to supplement thrust to an amount corresponding to hydraulic pressure is provided. A fastening part pressing against a die stack (4) is configured by a booster mechanism using a lever and a shear guide (24) is pressed against a horseshoe (13) to fasten it in the extrusion direction. Further, a clearance between a surface of the die stack and a shear knife can be held constant. Also, a booster mechanism using a lever is employed for a tilt mechanism for the shear guide in the extrusion press.

Abstract: A shearing device of an extrusion press for cutting off a discard includes a first drive device; a means for converting rotational motion generated by the first drive device to linear motion; a shearing-slide drive frame caused to move linearly by the means for converting rotational motion to linear motion, which shearing-slide drive frame is coupled to a shearing slide to which a shearing blade is fixed; a slide part coupled with the shearing-slide drive frame through a link unit; and a second drive device causing the slide part move linearly to cause the shearing-slide drive frame move linearly, wherein the first drive device and the second drive device are arranged in parallel with the means for converting rotational motion to linear motion.

Abstract: A shear device (21) of an extrusion press having a booster mechanism using an air cylinder or electric motor to supplement thrust to an amount corresponding to hydraulic pressure is provided. A fastening part pressing against a die stack (4) is configured by a booster mechanism using a lever and a shear guide (24) is pressed against a horseshoe (13) to fasten it in the extrusion direction. Further, a clearance between a surface of the die stack and a shear knife can be held constant. Also, a booster mechanism using a lever is employed for a tilt mechanism for the shear guide in the extrusion press.

Abstract: A defect on the surface or in the surface layer of a moving material can be detected by using a method comprising steps of: heating the surface of the material, obtaining thermal image data of the surface of the material using an infrared thermography camera while the surface of the material is being heated up at the heating step or being cooled down after heating, and detecting the defect by calculating Laplacian with respect to temperature of the surface represented by the thermal image data. When the thermal image data is obtained while the material is being heated up, a heating device and the camera is arranged so that thermal energy emitted from the heating device is reflected by the material to come into the camera.

Abstract: The present invention relates to a method of arranging and setting spray nozzles in a cooling apparatus comprising a plurality of pairs of constraining rolls for constraining and conveying a hot steel plate and one or more lines of spray nozzles between the pair of constraining rolls, each line having a plurality of spray nozzles and is disposed in a direction perpendicular to processing, and to the cooling apparatus and the method of cooling. The invention is characterized in that the spray nozzles are arranged such that a distribution of values ?Pn between two edges of the steel plate in the direction perpendicular to processing is not less than 80% of its highest value, with P being cooling water impact pressure on the cooling surface, ?Pn being the value of n power of P integrated in the processing direction between the pairs of constraining rolls, and 0.05?n?0.2.

Abstract: A defect on the surface or in the surface layer of a moving material can be detected by using a method comprising steps of: heating the surface of the material, obtaining thermal image data of the surface of the material using an infrared thermography camera while the surface of the material is being heated up at the heating step or being cooled down after heating, and detecting the defect by calculating Laplacian with respect to temperature of the surface represented by the thermal image data. When the thermal image data is obtained while the material is being heated up, a heating device and the camera is arranged so that thermal energy emitted from the heating device is reflected by the material to come into the camera.

Abstract: The present invention relates to an apparatus for cooling hot steel plate applied for controlled cooling of hot steel plate, obtained by hot rolling, while processing it constrained by constraining rolls and obtaining a steel material excellent and uniform in shape characteristics and provides a method of arranging and setting spray nozzles enabling uniform cooling in a direction perpendicular to processing and provides a method of arranging and setting spray nozzles of a spray cooling apparatus using two or more types of nozzles differing in amounts of water and spray regions to obtain a broad range of adjustment of amounts of water, wherein the spray nozzles are arranged so that a value of an n power of the impact pressures of the cooling water sprayed from the spray on the cooling surface integrated in the processing direction between pairs of constraining rolls becomes within ?20% of the highest value in the direction perpendicular to processing, where, 0.05?n?0.

Abstract: The present invention relates to an apparatus for cooling a hot steel plate which is processed and constrained by constraining rolls and a method of arranging and setting spray nozzles enabling uniform cooling in a direction perpendicular to processing. In the apparatus and method of the invention, the spray nozzles are arranged so that a value of n power of the impact pressure of the cooling water on the cooling surface integrated in the processing direction between pairs of constraining rolls becomes within ?20% of the highest value in the direction perpendicular to processing, where 0.05?n?0.2.

Abstract: An apparatus for controlled cooling of hot steel plate while constraining and conveying the plate by constraining rolls horizontally which is inexpensive and enabling continuous control of the cooling ability over a broad range, that is, a cooling apparatus for spraying hot steel plate hot rolled and transferred between pairs of constraining rolls with cooling water from pluralities of lines of spray nozzles so as to cool the same, which apparatus has lines of gentle cooling spray nozzles and lines of strong cooling spray nozzles with different orifice shapes and enables continuous control of the cooling ability over a broad range due to the fact that a maximum cooling water impact pressure integrated value of the lines of gentle cooling spray nozzles and a minimum cooling water impact pressure integrated value of the lines of strong cooling spray nozzles are continuous.

Abstract: An apparatus for controlled cooling of hot steel plate while constraining and conveying the plate by constraining rolls horizontally which is inexpensive and enabling continuous control of the cooling ability over a broad range, that is, a cooling apparatus for spraying hot steel plate hot rolled and transferred between pairs of constraining rolls with cooling water from pluralities of lines of spray nozzles so as to cool the same, which apparatus has lines of gentle cooling spray nozzles and lines of strong cooling spray nozzles with different orifice shapes and enables continuous control of the cooling ability over a broad range due to the fact that a maximum cooling water impact pressure integrated value of the lines of gentle cooling spray nozzles and a minimum cooling water impact pressure integrated value of the lines of strong cooling spray nozzles are continuous.

Abstract: A method of production of an ultralow carbon cast slab characterized by adding Ti to molten steel decarburized to a carbon concentration of 0.01 mass % or less, further adding at least one of Ce, La, and Nd, and using an immersion nozzle to inject the above molten steel from a tundish to a casting mold for continuous casting while maintaining a flow rate of Ar gas blown from any location in a range from a tundish upper nozzle to discharge ports of said immersion nozzle at 3 Nl (normal liter)/min or less.

Abstract: The present invention relates to an apparatus for cooling hot steel plate applied for controlled cooling of hot steel plate, obtained by hot rolling, while processing it constrained by constraining rolls and obtaining a steel material excellent and uniform in shape characteristics and provides a method of arranging and setting spray nozzles enabling uniform cooling in a direction perpendicular to processing and provides a method of arranging and setting spray nozzles of a spray cooling apparatus using two or more types of nozzles differing in amounts of water and spray regions to obtain a broad range of adjustment of amounts of water, wherein the spray nozzles are arranged so that a value of an n power of the impact pressures of the cooling water sprayed from the spray on the cooling surface integrated in the processing direction between pairs of constraining rolls becomes within ?20% of the highest value in the direction perpendicular to processing, where, 0.05?n?0.

Abstract: A billet produced by continuous casting having little central segregation, in particular a billet of high carbon steel produced by continuous casting, and a manufacturing method therefor are provided. In the continuous casting billet, the size of the dendritic equiaxed crystal in a billet central portion is reduced to be not more than 6 mm. For this purpose, electromagnetic stirring is performed so that the inclining angle of the primary dendrite within 10 mm of a billet surface layer is increased to be not less than 10°. Furthermore, the mechanical soft reduction is performed during continuous casting so that the diameter of the center porosity in the billet central portion is reduced to be not more than 4 mm. Thereby, in particular in the manufacturing of the continuous casting billet having a carbon content of not less than 0.

Abstract: A transferred plasma heating anode for heating a molten metal in a container by applying Ar plasma generated by passing a direct current through the molten metal, the transferred plasma heating anode comprising; an anode, composed of a conductive metal, that has an internal cooling structure, a metal protector having an internal cooling structure that is placed outside the anode with a constant gap between the anode and the protector, and a gas supply means that supplies an Ar-containing gas to the gap, is characterized by the central portion on the external surface of the anode tip end being inwardly recessed.

Abstract: A billet produced by continuous casting having little central segregation, in particular a billet of high carbon steel produced by continuous casting, and a manufacturing method therefor are provided. In the continuous casting billet, the size of the dendritic equiaxed crystal in a billet central portion is reduced to be not more than 6 mm. For this purpose, electromagnetic stirring is performed so that the inclining angle of the primary dendrite within 10 mm of a billet surface layer is increased to be not less than 10°. Furthermore, the mechanical soft reduction is performed during continuous casting so that the diameter of the center porosity in the billet central portion is reduced to be not more than 4 mm. Thereby, in particular in the manufacturing of the continuous casting billet having a carbon content of not less than 0.

Abstract: A transferred plasma heating anode for heating a molten metal in a container by applying Ar plasma generated by passing a direct current through the molten metal, the transferred plasma heating anode comprising; an anode, composed of a conductive metal, that has an internal cooling structure, a metal protector having an internal cooling structure that is placed outside the anode with a constant gap between the anode and the protector, and a gas supply means that supplies an Ar-containing gas to the gap, is characterized by the central portion on the external surface of the anode tip end being inwardly recessed.

Abstract: Hot steel plate as hot-rolled is passed forward longitudinally through pairs of top and bottom rollers disposed in the direction of the plate travel. The steel plate is cooled with water supplied to its top and bottom surfaces from the nozzles on a plurality of cooling units disposed in the same longitudinal direction. Each cooling unit is disposed between adjoining pairs of the top and bottom rollers. Before cooling is started, the temperature distribution in the steel plate is determined and the desired mean cooling rate is set. The distance from the plate edge over which the supply of the cooling water at least to the bottom side of the plate is to be cut off is determined for each cooling unit on the basis of the determined temperature distribution and preset mean cooling rate. By so doing, the temperature of the inner edge portion of the steel plate is kept above the temperature of the middle portion, thereby allowing the Ar.sub.