Abstract: A batch annealing furnace includes a coil support base on which an end face of a coil is mounted and that supports the coil with an axis of the coil being upright, an inner cover that covers an entire body of the coil mounted on the coil support base, and a cooling pipe that extends downward from the upper part of the inner cover to a cavity of the inner peripheral part of the coil mounted on the coil support base and cools the coil from the inner surface side by passing a coolant through the inside of the cooling pipe.

Abstract: A batch annealing furnace includes a coil support base on which an end face of a coil is mounted and that supports the coil with an axis of the coil being upright, an inner cover that covers an entire body of the coil mounted on the coil support base, and a cooling pipe that extends downward from the upper part of the inner cover to a cavity of the inner peripheral part of the coil mounted on the coil support base and cools the coil from the inner surface side by passing a coolant through the inside of the cooling pipe.

Abstract: A coated steel sheet composed of a steel sheet and at least two types of coating layers formed thereon is provided with an electrodeposition painting having a superior appearance. The coated steel sheet has an arithmetic mean roughness Ra, which is defined by JIS B 0601-1994, of from about 0.7 to about 1.5 ?m and a peak per inch PPI of from about 180 to about 250.

Abstract: A coated steel sheet composed of a steel sheet and at least two types of coating layers formed thereon is provided with an electrodeposition painting having a superior appearance. The coated steel sheet has an arithmetic mean roughness Ra, which is defined by JIS B 0601-1994, of from about 0.7 to about 1.5 &mgr;m and a peak per inch PPI of from about 180 to about 250.

Abstract: A continuous hot rolling mill with a metal block conveying apparatus and a metal block joining apparatus which moves with the metal blocks along the metal block conveying apparatus to conform a joining operation. The metal block conveying apparatus uses rollers supported by cylinders with a common hydraulic circuit which allows the cylinders to follow guide rails on the metal block joining apparatus and lower out of the path of the metal block joining apparatus and then return to a metal block support position after the metal block joining apparatus' passage without individual control circuits and valves for each of the cylinders.

Abstract: The invention comprises a continuous hot rolling method in which a rear end portion of a preceding metal block and a fore end portion of a succeeding metal block are cut and the metal blocks are joined to each other by heating and pressing followed by a finish rolling. A region of each metal block is restrained from a clamping position to the end portion thereof in order to prevent a change in level of the metal blocks in heating and pressing the piece. The end portions of the metal blocks can be thus prevented from deformation.

Abstract: During rolling with a rolling mill, which includes a sheet shape altering device capable of altering a mechanical sheet crown, while the sheet shape altering device is operated correspondingly with a target mechanical sheet crown set value during the dimensional alteration in rolling, the invention enables a stable sheet shape to be achieved, even when the mechanical sheet crown is altered to a large extent during rolling. Specifically, the target mechanical sheet crown set value, during the dimensional alteration in rolling, is previously set based on target mechanical sheet crown set values, before and after the dimensional alteration, prior to start of the dimensional alteration in rolling. The sheet shape altering device is then operated so that an actual mechanical sheet crown, during the dimensional alteration in rolling, is equal to the target mechanical sheet crown set value during the dimensional alteration in rolling.

Abstract: A continuous hot rolling method is available for continuously hot finish rolling steel pieces. The trailing end of a preceding steel piece and the leading end of a succeeding steel piece are cut by a drum shear which sandwiches the steel piece between its upper drum and lower drum, having cutting blades on the peripheries of the drums. The cut ends are heated to raise the temperatures thereof by high-frequency induction heating, pressed against each other to butt-join the cut ends. The joined steel pieces are then supplied to a rolling equipment. The trailing end of the preceding steel piece and the leading end of the succeeding steel piece are cut individually by two pairs of the cutting blades. One pair of the cutting blades has the obverses of the blades oriented in opposite directions in the obverse side and the reverse side of the steel piece.

Abstract: A method and apparatus for continuously finishing hot-rolling steel strips include partially joining a rear end of a preceding steel strip and a leading end of a succeeding steel strip after the strips have passed through a rough hot-rolling step. The joint is flattened. The joint is rolled with a first stand of a tandem rolling mill. The mill is provided with a plurality of stands that includes a pair of work rolls and backup rolls and/or intermediate rolls, so that a compression stress acts at the unjointed section of the strips in the longitudinal direction of the joint while tracking the joint. Shape-control-rolling is performed on the joint with a second and succeeding stands so that a section of the steel strip other than the joint is subjected to the shape-control-rolling at all the stands.

Abstract: A method for continuously hot-rolling steel pieces, includes butt-joining the rear end of the preceding steel piece and the leading end of the succeeding steel piece, then finish-rolling the butt-joined steel pieces by supplying a continuous hot rolling facility provided with a plurality of stands having a bending function of a work roll. The method involves estimating the variation of the rolling force occurring during rolling the joint of the steel pieces at the non-stationary zone caused by said joint, calculating the changing bending force of the work roll during rolling the joint of the steel pieces from the estimated variation of the rolling force, and determining the pattern for changing the bending force taking account of said changing force, and rolling the joint of the steel pieces by regulating the bending force in response to said pattern over at least one stand, while tracking down the joint of the steel piece immediately after joining.

Abstract: When a semi-solidified metal composition is formed in a forging die assembly, it is formed under conditions satisfying particular mass fraction solid and flowing rate in the die and then held under a given pressure until the metal composition is completely solidified.

Abstract: In a method and an apparatus for producing a solid-liquid metal mixture in which non-dendritic primary solid particles are dispersed into the remaining liquid matrix through electromagnetic induction system, a core member is arranged inside a cooling agitation tank provided with an electromagnetic induction coil therearound.

Abstract: Semi-solidified metal compositions are stably produced by pouring molten metal into a cooling agitation vessel, agitating it while cooling to produce a slurry of semi-solidified metal composition at a solid-liquid coexistent state and discharging out the semi-solidified metal composition from a discharge port of the vessel. In this case, the cooling agitation is carried out so that a relation of fraction solid, solidification rate and shear rate satisfies the following equation (1).eta.=a/2(1/f.sub.s -1/f.sub.scr).ltoreq.10 (1).

Abstract: In a method and an apparatus for producing a solid-liquid metal mixture in which non-dendritic primary solid particles are dispersed into the remaining liquid matrix through electromagnetic induction system, a core member is arranged inside a cooling agitation tank provided with an electromagnetic induction coil therearound.