Abstract: A trailing end of a preceding bar is arranged slantingly by an angle .theta. relative to a succeeding bar such that the lower edge of the leading end face of the succeeding bar is vertically shifted from the lower edge of the trailing end face of the preceding bar with the leading end face of the succeeding bar abutting against the trailing end face of the preceding bar. After that, the succeeding bar is vertically depressed by applying a predetermined force. Since the trailing end face is inclined by .theta. relative to the leading end face, the depression causes a relative slide between surfaces of both the end faces and, at the same time, a pressure P is also produced by the wedge effect, the pressure P causing a compression force and a plastic deformation between both the end faces.

Abstract: In a continuous hot rolling system, at least one melt-cut torch is set in a predetermined positional relationship with respect to a trailing end of a preceding hot material and a leading end of an adjacent succeeding hot material. An injected flow of cutting gas from the melt-cut torch is blown against a portion of at least one of the trailing end of the preceding material and the leading end of the succeeding material to melt-cut the portion. The portion extends from an end surface of the one end over a predetermined length. The trailing end of the preceding material and the leading end of the succeeding material are forced against each other and are butt-joined to each other. By doing so, there are produced joining surfaces superior in surface accuracy and high in temperature, to allow joining to be high in accuracy and strength. This joining may be made with respect to slabs before rough rolling, or may be made with respect to bars after rough rolling.

Abstract: The presence of carbon dioxide contained in a gas can be detected through measurement of the change in the electrical resistance of a hydroxyapatite in contact with carbon dioxide gas. The sensitivity of the hydroxyapatite to carbon dioxide gas can be enhanced by the formation of a composite of the hydroxyapatite with an inorganic carbonate, e.g., sodium carbonate or calcium carbonate. The sensitivity to carbon dioxide gas can be further enhanced by the formation of a composite of the hydroxyapatite with an inorganic halide, e.g., calcium chloride.

Abstract: A twin-roll type continuous casting apparatus comprises a pair of rotatable drums and a pair of side dams disposed on both axial ends of the drums so that a pool of molten steel is defined by the drums and the side dams. As the drums are rotated in counter directions, the molten steel is cooled so that the molten steel is partially solidified to form solidification shells which are then pressure-bonded to each other as they pass through the narrowest gap defined between the drums, so that a steel sheet is formed by continuous casting. The side dam is composed of a side refractory part which functions to maintain the pool of molten steel and a metallic member which supports the side refractory part and which serves as a cooling plate for cooling the steel.

Abstract: A pair of rotating rolls cool the molten metal to form a solidified shell on the surface thereof and compress the solidified shells to produce a metal sheet. A number of bearing boxes are disposed in a housing for rotatably supporting the respective ends of the rolls, and a rigid member is disposed between the bearing boxes in the housing. A prestress or initial force is applied to the rigid member through the bearing box, and a controller regulates the rotating speed of a drive in order to control the separating force occurring at a compression of the solidified shells by the rolls. By controlling the separating force, a leakage of the molten metal is prevented and a sheet metal having a uniform thickness is continuously obtained.

Abstract: A belt type continuous casting machine having a container for accommodating molten steel therein, a nozzle for supplying the molten steel from the container, a belt mold having a pair of metal belts and a pair of side members, and a cooling pad positioned adjacent to the back surface of the metal belt for forming a gap acting as a water film portion therebetween. The cooling pad is provided with a plurality of inlet ports and outlet ports for enabling a flow of cooling water into the water film portion therethrough. The diameters of these ports and the vertical distance between the inlet port and the adjacent outlet port are varied for controlling fluid pressure in the water film portion in correspondence with an external load acting on the metal belt. By securing a desired water film thickness deformation of the belt mold is prevented, and a flat cast slab with a good surface is obtained.

Abstract: In a continuous galvanizing line, oscillation of a steel strip withdrawn from a molten zinc metal bath is prevented by anti-vibration magnets disposed in the vicinity of the respective side edges of the steel strip. The magnets cause tension in the strip in a direction of strip width and amplitude of the oscillation of the strip perpendicular to the strip surfaces is reduced. Also, by magnetic force of the magnet, bending of the running strip is cured and uniform coating is obtained. A gap between the magnet and the strip side edge is automatically controlled by detecting the gap continuously.

Abstract: A method of and apparatus for effecting slitting rolling on a steel sheet, wherein a wide steel sheet is slit in the breadthwise direction into a plurality of steel sheets having smaller width and the slit steel sheets are moved in the breadthwise direction to form and maintain a predetermined distance therebetween. The steel sheets are then rolled independently to have edge drops on both breadthwise ends thereof, and, thereafter, the slit steel sheets having edge drops are subjected to a plating step. According to the invention, it is possible to obtain plated steel sheet product of high quality by slitting rolling.

Abstract: A continuous casting apparatus includes a mold defined by a pair of side plates in a curved shape or ring-shaped rotary members and a pair of endless belts. One of the belts is inscribed in the side plates or the ring-shaped rotary members. The other belt is circumscribed with the side plates or the ring-shaped rotary members. The belts rotate in synchronism with the cast piece. On the rear surfaces of the belts, there are provided means for supporting and cooling the mold and cast piece.

Abstract: A method of and apparatus for cooling and guiding a strip of metal discharged from a casting mold into a straightening section of a continuous casting machine in which a casting wheel is provided with a peripheral groove with a portion of its length closed by an endless belt to form the casting mold. A surface of the metal strip on the side of the casting wheel is cooled by a sheet of liquid coolant which flows on the surface and guided by a hydrostatic bearing of the liquid coolant while the metal strip is gradually straightened.

Abstract: A coil unwind method wherein a large coil is formed by successively jointing a plurality of coils unwound from an unwind machine for unwinding transportable coils, and thereafter a strip is unwound from said large coil to be supplied to a processing equipment.