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: According to the invention, the rear end of a preceding metal piece and a front end of a succeeding metal piece are heated, pressed and joined prior to the finishing hot rolling. An alternating magnetic field running through the metal pieces in the thickness direction thereof is generated in an end region on opposed faces of the respective metal pieces to perform heating. Another alternating magnetic field whose direction is reverse with respect to that of the former alternating magnetic field is partially generated in the end region on the opposed faces of the metal pieces and in either a region where the metal pieces exist or a region outside width ends of the metal pieces. This assures a uniform heating of the end region on the opposed faces of the metal pieces over their full width to reliably join the both metal pieces to each other.

Abstract: A method and apparatus for joining metal pieces wherein the rear end of a preceding metal piece and a front end of a metal piece are heated and then pressed together prior to hot finished rolling. The temperature the ends of the metal pieces are heated to is a temperature range between the solidus and liquidus line temperatures of the metal(s) to be joined.

Abstract: According to the invention, the rear end of a preceding metal piece and a front end of a succeeding metal piece are heated, pressed and joined prior to the finishing hot rolling. An alternating magnetic field running through the metal pieces in the thickness direction thereof is generated in an end region on opposed faces of the respective metal pieces to perform heating. Another alternating magnetic field whose direction is reverse with respect to that of the former alternating magnetic field is partially generated in the end region on the opposed faces of the metal pieces and in either a region where the metal pieces exist or a region outside width ends of the metal pieces. This assures a uniform heating of the end region on the opposed faces of the metal pieces over their full width to reliably join the both metal pieces to each other.

Abstract: Method and apparatus for joining metal pieces using induction heating. Metal pieces to be joined are placed end-to-end with a gap between them and induction heated in the thickness portion. To maximize speed and even heating edge-to-edge of the ends, members of a magnetic substance are provided in a gap between the inductor and the piece to be heated, thereby enhancing local heating effect by increasing magnetic flux density. Once heated, the ends are pressed together end-to-end for joining.

Abstract: In the present invention, in cutting the top and bottom surfaces of a hot-rolled sheet by the rotation of milling cutters holding the sheet therebetween in the thickness direction of the sheet in the running process of the hot-rolled sheet, the cutting resistance determined by the cutting conditions including the type of hot-rolled sheet, the temperature in cutting, and the cut depth is controlled by the adjustment of cut depth, and cutting is performed by making the tension produced on the hot-rolled sheet by the cutting resistance lower than the breaking strength of the joint portion to prevent the breakage of hot-rolled sheet.

Abstract: In the present invention, in cutting the top and bottom surfaces of a hot-rolled sheet by the rotation of milling cutters holding the sheet therebetween in the thickness direction of the sheet in the running process of the hot-rolled sheet, the cutting resistance determined by the cutting conditions including the type of hot-rolled sheet, the temperature in cutting, and the cut depth is controlled by the adjustment of cut depth, and cutting is performed by making the tension produced on the hot-rolled sheet by the cutting resistance lower than the breaking strength of the joint portion to prevent the breakage of hot-rolled sheet.

Abstract: An apparatus for joining metal pieces using induction heating. Preceding and succeeding metal pieces are followed by a carriage which carries an inductor. The inductor has the ability to move in the longitudinal direction of the metal pieces relative to the carriage to allow the inductor to move more or less upon the preceding or succeeding metal pieces to increase or decrease the induction heating effect, thereby taking into account any thickness variation of the metal pieces and yet still heating them evenly with regard to each other, prior to their being pressed against each other for joining before hot finishing rolling.

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: 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 heng 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: A surface cutting apparatus for hot-rolled products cuts top and bottom surfaces of a hot-rolled steel product continuously or intermittently by passing the steel product between a pair of rotary drums (milling cutters) that rotate in a direction reverse to each other. The apparatus includes a disk having a larger diameter than that of the rotary drums at one or both ends of at least one of the rotary drums. The disk recognizes a gap between the rotary drums, allowing a zero adjustment to be made without excessively pressing the rotary drums. The measurement can be by a non-contact distance meter, eddy-current type sensor or other sensor.

Abstract: A post continuous hot rolling method where a rear end portion of a preced metal block and a fore end portion of a succeeding metal block are cut and the metal blocks joined to each other by heating and pressing followed by a finish rolling, wherein a poorly joined portion is removed by shaving the defective portion through application of rotating cutters prior to a final finish rolling of the joined blocks.

Abstract: According to the invention, the rear end of a preceding metal piece and a front end of a succeeding metal piece are heated, pressed and joined prior to the finishing hot rolling. An alternating magnetic field running through the metal pieces in the thickness direction thereof is generated in an end region on opposed faces of the respective metal pieces to perform heating. Another alternating magnetic field whose direction is reverse with respect to that of the former alternating magnetic field is partially generated in the end region on the opposed faces of the metal pieces and in either a region where the metal pieces exist or a region outside width ends of the metal pieces. This assures a uniform heating of the end region on the opposed faces of the metal pieces over their full width to reliably join the both metal pieces to each other.

Abstract: A surface cutting method for a hot-rolled steel product that includes a joint portion having a predetermined breaking strength includes a step of clamping the steel product between a pair of milling cutters that are arranged on top and bottom surfaces of the steel product, while the steel product is conveyed in a longitudinal running direction. The top and bottom surfaces of the steel product are subjected to cutting by rotating the milling cutters in a rotating direction. A cutting resistance applied to the milling cutters during the cutting is determined based on parameters including type of steel, width, thickness, surface temperature and conveying speed of the steel product, as well as circumferential speed and cutting depth of the milling cutters.

Abstract: A method of producing steel pipes is provided which comprises the steps of providing a steel strip, processing the steel strip into a preheated open pipe, preheating the open pipe at its two opposite longitudinal edges at a temperature higher than about the Curie point, heating the open pipe at the two opposite edges at a temperature higher than about 1,300.degree. C. but lower than the melting point of the steel strip, pressure welding the resultant open pipe with a squeeze roll to thereby form a steel pipe, smoothing the steel pipe at its thick-walled portion formed on an outer surface of the welded seam, and subsequently cutting or winding the resulting steel pipe. An apparatus adapted to form the steel pipes is also provided.

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: This invention rapidly and surely joins sheet bars to each other for continuously hot rolling in a high productivity by a combination of a treatment that the front end portion and the back end portion of these sheet bars are contacted and heated at such a contact region by applying alternating magnetic fields so as to pass in a thickness direction of the sheet bar with a treatment of pushing at least one of these sheet bars.

Abstract: In this invention, a back end portion of a preceding sheet bar and a front end of a succeeding sheet bar are cut in a transfer line at an entrance side of a finish rolling mill so that at least both side edge regions of these sheet bars are contacted with each other at a butted contact state thereof and a gap is formed between both end portions and then portions to be joined int he preceding and succeeding sheet bars are locally heated and pushed to join them while gradually enlarging a joining area, whereby the required time is largely reduced as compared with the conventional technique and also it is attempted to miniaturize the heating apparatus and shorten the length of the apparatus.