Cooling device for hot-rolled steel strip

Abstract

Provided is a cooling system for a hot-rolled steel strip capable of increasing the cooling rate for rapidly cooling a rolled steel immediately after rolling and suitable for an apparatus for manufacturing a hot-rolled steel strip having a fine-grained structure. For this purpose, guides (16A, 16B) having guiding surfaces (16a, 16b) to guide a rolled steel (W) exiting work rolls (12A, 12B) in the conveyance direction are provided at exits of the work rolls in a final stand (Sn) of a finish rolling mill line in a manner that the guides can follow a change in the diameter of the work rolls, a number of injection holes (21A, 21B) are formed in the guides, and a number of rolled steel cooling nozzles (23A, 23B) are provided to spray a large amount of cooling water through the injection holes directly onto the rolled steel.

Description

technical field [0001] The present invention relates to a cooling device for a hot-rolled steel strip, and more specifically, to a hot-rolled steel strip suitable for producing a ferrite structure with a fine-grained grain size of, for example, 3 to 4 μm or less. cooling device in the device. Background technique [0002] As a cooling device for a hot-rolled steel strip, there are devices disclosed in Patent Documents 1 to 3, for example. That is, Patent Document 1 describes a device in which the first cooling device installed immediately behind the final stand in the finishing mill row of the hot rolling facility is equipped with a cooling device for forming a strip shape or an ellipse shape on the surface to be cooled of the steel plate. The nozzles in the jet collision area and the barrier rollers used to block the cooling water sprayed from the nozzles are formed with a water storage tank for cooling water in the area between the rollers of the final stand and the barri...

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Problems solved by technology

[0019] However, in the above-mentioned conventional cooling device, either the cooling capacity is insufficient or the cost is high because of the large size of the device, therefore, it cannot be realized as a device for manufacturing a hot-rolled steel strip composed of a fine grain structure.

[0020] That is, in the cooling device of Patent Document 1, a non-cooling area in which measuring equipment is arranged is provided between the first cooling device and the second cooling device. above) and it is necessary to arrange a plurality of nozzles near the output side of the work roll, and it is necessary to provide a guide with a guide surface, but there is no description about the guide

[0021] In addition, in the cooling device of Patent Document 2, since a plurality of cooling units are arranged in the conveying direction, it is not cooling immediately after rolling, but the rolls are arranged at about 1.1 to 1.3 times the roll diameter. There are enough nozzles, so the cooling rate cannot be obtained sufficiently, so it cannot be applied to the device for manufacturing hot-rolled steel strip composed of fine-grained structure.

[0022] In addition, in the cooling device of Patent Document 3, the rolling material cooling nozzle is arranged on the output side of the workpiece roll, but the spray hole for directly spraying cooling water on the rolling material to cool the rolling material is not provided on the wiper. Therefore, In the lower part (or upper part) of the part where the wiper is installed, there is an area where the rolled product cannot be cooled, so that the cooling rate cannot be realized sufficiently

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