Nippon Steel Sumitomo Metal Corporation

Shingo Kuriyama

Koji Noguchi

Shigeru Ogawa

Daisuke Kasai

Tooru Akashi

Takeo Itoh

Hitoshi Nikaido

Fuminori Tasaki

The apparatus for cooling a hot-rolled steel sheet of the invention includes a thermometer that measures the temperature of the hot-rolled steel sheet; a shape meter that measures a shape of the hot-rolled steel sheet; a top side cooling device that cools a top surface of the hot-rolled steel sheet in a cooling section; a bottom side cooling device that cools a bottom surface of the hot-rolled steel sheet in the cooling section; and a control device that controls at least one of an amount of heat dissipated from the top surface by cooling and an amount of heat dissipated from the bottom surface by cooling of the hot-rolled steel sheet in the cooling section by controlling the top side cooling device and the bottom side cooling device based on temperature measurement results and shape measurement results.

Apparatus for cooling hot-rolled steel sheet

A method for manufacturing a steel sheet of the invention includes a hot-rolling process in which a steel material is hot-rolled using a finishing mill so as to obtain a hot-rolled steel sheet; and a cooling process in which the hot-rolled steel sheet is cooled. The hot-rolling process includes a target steepness-setting process in which a target steepness of the edge wave shape is set based on first correlation data indicating a correlation between a steepness of the edge wave shape of the hot-rolled steel sheet and a temperature standard deviation Y; and a shape-controlling process in which operation parameters of the finishing mill are controlled so as to match the steepness of the edge wave shape with the target steepness.

Method for manufacturing steel sheet

The method for cooling a hot-rolled steel sheet of the invention includes a target ratio-setting process in which a top and bottom heat transfer coefficient ratio X1, at which a temperature standard deviation Y becomes a minimum value Ymin, is set as a target ratio Xt based on correlation data between a top and bottom heat transfer coefficient ratio X of the hot-rolled steel sheet and the temperature standard deviation Y of the hot-rolled steel sheet; and a cooling control process in which at least one of an amount of heat dissipated from a top surface by cooling and an amount of heat dissipated from a bottom surface by cooling of the hot-rolled steel sheet in the cooling section is controlled so that the top and bottom heat transfer coefficient ratio X of the hot-rolled steel sheet in the cooling section matches the target ratio Xt.

Method for cooling hot-rolled steel sheet

Growing community of inventors

Tokyo, Japan

Shingo Kuriyama