Method for manufacturing hot-rolled steel sheet, steel sheet cutting location setting device, steel sheet cutting location setting method, and steel sheet manufacturing method

摘要

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.