| 摘要 |
A method of cooling a steel sheet, in which improved uniform cooling in the direction of steel sheet conveyance can be attained. The method is characterized by the following. In anterior section (4a) of cooling unit, during the passage of distal end region (11) of steel sheet, the cooling water rate is set to noninjection of water. At the passage of distal part region (12), the cooling water rate is gradually increased from 80 to 95 vol.% (Qiront) of standard water rate density (Qo). At the arrival of the boundary between distal part region and middle part region, water injection is conducted so that the cooling water rate agrees with the standard water rate density. During the passage of the middle part region, water injection is continued at the standard water rate density. In posterior section (4b) of the cooling unit, during the passage of the distal end region of the steel sheet, the cooling water rate is set to 80 to 95 vol.% of the standard water rate density. At the passage of the distal part region, the cooling water rate is gradually increased from 80 to 95 vol.% of standard water rate density. At the arrival of the boundary between distal part region and middle part region, water injection is conducted so that the cooling water rate agrees with the standard water rate density. During the passage of the middle part region, water injection is continued at the standard water rate density.
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