Metal plateness controlling method and device

A method for controlling flatness of a metal sheet or plate comprising the following steps:

• (a) measuring surface temperatures of the metal sheet or plate at edge portions and a center portion across a width of the metal sheet or plate at an exit of a tandem or reversing finishing mill,
• (b) controlling heating temperatures of the edge portions and/or the center portion based on the measured surface temperatures, and then,
• (c) water-cooling and/or hot-leveling the metal sheet or plate,
• whereby the heating temperatures of the edge portions of the steel sheet or plate are controlled so that the surface temperature of each edge portion measured in a range of 50 to 200 mm from each edge as the edge portion, and that of the center portion thereof, becomes within ±50° C. of each other.

A method for controlling flatness of a metal sheet or plate comprising the following steps:

• (a) measuring surface temperatures of the metal sheet or plate at edge portions and a center portion across a width of the metal sheet or plate after one or more rolling passes at a reversing finishing mill,
• (b) controlling heating temperatures of the edge portions and/or the center portion based on the measured surface temperatures, and then
• (c) water-cooling and/or hot-leveling the metal sheet or plate,
• whereby the heating temperatures of the edge portions of the steel sheet or plate are controlled so that the surface temperature of each edge portion measured in the range of 50 to 200 mm from each edge as the edge portion, and that of the center portion thereof, become within ±50° C. of each other.