Nippon Steel Corporation

Hiroshi Niitani

Yoshihiro Serizawa

Satoru Hayashi

Tomofumi Hosho

Takayuki Murai

Yoshiaki Suematsu

Naoko Katou

Tomoya Nakao

Takumu Ushizawa

Rumi Matsumoto

Nobumasa Hayashi

The present cooling device includes: when cooling regions obtained by dividing an entire cooling region into a plurality of portions in a steel sheet conveyance direction and three or more portions in a width direction are set as divided cooling surfaces, a cooling water nozzleand a switching device that switches between collision and non-collision of cooling water jetted from the cooling water nozzlewith the divided cooling surface, the cooling water nozzleand the switching device provided for each of the divided cooling surfaces; and a control device that controls operation of the switching device based on a width-direction temperature distribution. The cooling water nozzlehas a jet axis P inclined with respect to a vertical line to the entire cooling region when viewed in the steel sheet conveyance direction, and the cooling water goes to the side opposite to the cooling water nozzlein the width direction after colliding with the divided cooling surface.

Cooling device for hot-rolled steel sheet and cooling method of hot-rolled steel sheet

Provided is a cooling device, where a hot-finish-rolling mill includes a plurality of nozzles which spray cooling water toward one of or both of upper and lower surfaces of a hot-rolled steel sheet just after rolled by rolling stands, the nozzles are provided on the inside of the upper and lower guides or adjoining to the guides on a downstream side, and a nozzle spray distance changes depending on a position of the nozzle in a rolling direction, wherein a spray angle of the nozzle at a position whose nozzle spray distance is the largest is smaller than a spray angle of the nozzle at a position whose nozzle spray distance is the smallest, and the spray angle of the nozzle becomes the same or smaller as the nozzle spray distance becomes large.

Cooling device and cooling method of hot-rolled steel sheet

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Tokyo, Japan

Hiroshi Niitani