公开(公告)号：US20170182534A1

公开(公告)日：2017-06-29

申请号：US15314744

申请日：2015-05-13

Applicant: JFE STEEL CORPORATION

Inventor： Hiroto GOTO ,  Naoki NAKATA ,  Yukio KIMURA ,  Masaru MIYAKE ,  Satoshi UEOKA ,  Nobuo NISHIURA ,  Sonomi SHIRASAKI ,  Takaomi KATO

IPC: B21B15/00 ,  B21B1/38 ,  B21B1/26

CPC classification number: B21B15/0007 ,  B21B1/22 ,  B21B1/224 ,  B21B1/26 ,  B21B1/34 ,  B21B1/38 ,  B21B38/00 ,  B21B38/006 ,  B21B2001/225 ,  B21B2015/0014 ,  B21B2263/20

Abstract: A method for manufacturing a hot-rolled steel sheet having a large thickness and a large width, a larger sheet width and a lower temperature can stably be cut at a cutting load equal to that of a conventional steel sheet having a usual sheet thickness, a usual sheet width and a usual temperature. In a rough rolling step, the steel sheet is formed so that the shortest length L (mm) from a concave portion bottom to a convex portion top of the fishtail shape satisfies Equation (1) mentioned below, and an intermediate portion between the concave portion bottom and the convex portion top, defined as a desired cutting location, is cut: (2X+30)≦L≦300  (1), in which X is a maximum deviation (mm) of the cutting location of a crop cutting machine and 0≦X≦90.

公开(公告)号：US20190076896A1

公开(公告)日：2019-03-14

申请号：US15765557

申请日：2016-11-18

Applicant: JFE STEEL CORPORATION

Inventor： Hiroto GOTO ,  Yukio KIMURA ,  Satoshi UEOKA ,  Nobuo NISHIURA ,  Sonomi SHIRASAKI

IPC: B21B1/26

Abstract: A hot-rolled steel sheet not exceeding a coil opener allowable load during unwinding includes a steel sheet cut in unsteady portions at its longitudinal head and tail ends in a cutting step after a rough rolling step, having a width of 1,200 mm to 2,300 mm, a thickness of 13 mm to 25.4 mm, and at least an API standard X65-grade strength, and used in a state of being unwound after having been wound around a coil. A longitudinal end corresponding to the unwinding start includes a portion at its widthwise center recessed inwards in the longitudinal direction with respect to its two widthwise ends, the two widthwise ends projection sizes with respect to the recessed portion at the widthwise center are 20 to 295 mm, and the sum of the widths of projecting portions at the two widthwise ends is set to ¼ to ½ of the sheet width.