METHOD FOR COOLING A STEEL STRIP IN A CONTINUOUS-ANNEALING FURNACE

摘要

The present invention relates to a method for cooling a steel strip (1) in a continuous-annealig furnace. Conventionally, the steel strip (1) is cooled by a water medium and, thus, oxidation is inevitable. Recently developed roll cooling methods can prevent oxidation but are disadvantageous in that the steel strip (1) is nonuniformly cooled as seen in its short width direction. The present invention attains uniform cooling by means of feedback control and feedback-feedforward control, in which the blowing width of the gas-jet cooler (21, 53) is controlled by detecting the sheet temperature distribution with a thermometer(s) (24, 55, 60).