| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for suppressing the generation of local discoloration generated in the surface of a steel sheet after being immersed into water or a cleaning liquid and cooled in the outlet side of a continuous annealing furnace, to provide equipment suitable for this method, and a method for producing a cold rolled steel sheet free from local discoloration.SOLUTION: Provided is a method for cooling a cold rolled steel sheet characterized in that, at the outlet side of a continuous annealing, a steel sheet after annealing is immersed into water or a cleaning fluid and is cooled to 40°C or lower, thereafter, water is jetted thereto to water-wash the surface of the steel sheet, and successively, the steel sheet after the water washing is dried, also provided is cooling equipment for a cold rolled steel sheet at the outlet side of the continuous annealing furnace including: a cooling means of immersing a steel sheet into water or a cooling fluid; a water injection means of injecting water to the surface of the steel sheet after cooling; a water exhaustion means of exhausting water injected to the steel sheet; and a drying means of drying the steel sheet injected with water, and also provided is a method for producing a cold rolled steel sheet characterized in that a steel sheet is subjected to continuous annealing, is thereafter immersed into water or cleaning water and is cooled to 40°C or lower, water is injected thereto to water-wash the surface of the steel sheet, and successively, the steel sheet after the water washing is dried. |
