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 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: Herein disclosed is an endless hot rolling method using a hot strip mill substantially composed of a roughing mill and a finishing mill having a roll bender and a roll shifter to continuously roll sequentially joined different rolling materials. The method comprises the steps of: calculating a roll shift range in an axial direction for each rolling material so as to provide a desired crown; determining a rolling sequence so as to obtain a common roll shift range for each pair of neighboring rolling materials; connecting a preceding material at the tail end thereof to the head end of the succeeding material, between the roughing mill and the finishing mill; shifting the rolls during transition from the preceding material to the succeeding material so that the roll position corresponding to the joint of the two materials is within a common roll shift range for the materials; and changing the roll bending load in accordance with the roll shift pattern so as to achieve the desired crown of each material.

Abstract: A sheet crown control method and apparatus for use in endless rolling in which consecutively fed sheets are joined to each other to be continuously rolled through a rolling equipment line. The rolling equipment line includes a junction device for joining consecutively fed sheets to each other, a plurality of stands arranged in tandem on the downstream side of the junction device and having a roll bender load adjusting mechanism and a roll crossing mechanism. The roll cross angle of rolls incorporated in a stand of each rolling mill is set at a predetermined value beforehand if there is a roll cross angle that will enable a target sheet crown to be applied to each sheet and the roll bender load of each stand is adjusted on-line, thereby effecting sheet crown control. Rolling also may be performed while adjusting the roll cross angle of rolls incorporated in stands of each rolling mill on-line together with the roll bender load.

Abstract: A method of continuously hot-rolling sheet bars in which a roughly rolled leading sheet bar and a trailing sheet bar are abutted prior to a hot finish rolling step. Plastic deformation of either or both of the cut rear and front end portions of the leading and trailing sheet bars is applied. End portions are brought into contact with each other due to metal flow, forming a gap portion between the sheet bars. The thickness of the sheet bar around the gap portion is enlarged in comparison to the thickness of the contact portions, and hot finish rolling fills the gap so that the bars are strongly joined over their width.

Abstract: A wet skin-pass rolling method for rolling a steel sheet by a mill while adjusting the hardness of said steel sheet through control of the rolling reduction. The method comprises determining an allowable range of reduction ratio from a predetermined desired range of hardness of the product, determining a command delivery-side sheet thickness to be obtained at the delivery side of the mill on the basis of the sheet thickness measured at the entry side of the mill, and adjusting the sheet thickness control in accordance with the command delivery-side sheet thickness.

Abstract: A process and an equipment for micro-pattern forming on the surface of a rolling roll, and a metallic thin sheet and preparation thereof by transferring a micro-pattern on the surface by use of the roll are provided. Such a rolling roll can be attained by a method wherein resin film mixed with optical absorbing agent is formed on the surface, a Q switch YAG laser having an output of 5 to 100W is applied to make a marking on this resin film, a part of the coated film is removed in strict accordance with the pattern, then an etching process is applied to the roll surface. The metallic thin sheet skin pass rolled by this roll is used as a car panel and is superior in pressworkability and sharpness of reflections.

Abstract: A slab is successively fed between periodically moving press tools to reduce the slab in a widthwise direction. In this method, the leading and tail end portions of a given length in the slab are reduced at a reduced width wider than that of remaining steady portion.