COOLING APPARATUS FOR STEEL PLATE, APPARATUS FOR PRODUCING HOT ROLLED STEEL PLATE AND METHOD OF PRODUCING HOT ROLLED STEEL PLATE

摘要

PROBLEM TO BE SOLVED: To provide a cooling apparatus for hot rolled steel plates which can keep uniformity of high cooling even when cooling water is supplied at a high water amount density.SOLUTION: A cooling apparatus is arranged on the side of steps in the downstream of a hot finishing mill, is capable of injecting cooling water from a plurality of nozzles at a water amount density of 10 m/(mmin) or higher with an injection range of cooling water in the plate width direction of a steel plate of 1 m or greater and is characterized by meeting the condition (P-P)/P≥1.4, where P(kPa) is the impact pressure at a position where the impact pressure becomes maximum, P(kPa) is the impact pressure at a position where the impact pressure becomes minimum and P(kPa) is an average impact pressure of cooling water injected from the nozzle, when cooling water injected from a nozzle impacts on a steel plate according to an injection pattern for the nozzle.