COOLING CONTROL METHOD FOR STRIP

PURPOSE:To uniformize the quality of a material in the width direction by combining a 1st cooling means provided with movable drain plates and a 2nd cooling means having nozzles arranged at equal spaces and restricting a using ratio of the 1st cooling means within a specific percentage range to the total using ratio. CONSTITUTION:A cooling control device 5 is composed of nozzles 3 arranged at equal spaces, movable drain plates 2, and a driving shaft 1; the plates 2 are movable to an optical position by rotation of the shaft 1. By that composition, the device 5 optionally selects a 1st cooling means indirectly injecting cooling water onto edge parts of a strip 4 or a 2nd cooling means uniformly injecting cooling water. In the case of cooling the strip 4 in hot rolling, a using ratio of the 1st cooling means is limited to 40-80% of the total using ratio to restrict cooling. The quality of a material of the strip 4 in the width direction is uniformized and the shape quality of products is improved because the cooling is uniformized.