Patent ID: 6913659

Claim:
A method for rapidly cooling a steel strip traveling through a continuous annealing facility comprising: providing a cooling chamber in the continuous annealing facility, with the cooling chamber having a surface facing the traveling steel strip; providing a plurality of nozzles protruding from said surface of the cooling chamber; maintaining tips of said plurality of nozzles at a 50 to 100mm distance from said surface of the traveling steel strip; disposing the cooling chamber in the continuous annealing facility for providing an Re number at an edge of the traveling steel strip satisfying the expression: Re number≦500,000, wherein Re number at the edge of the steel strip is defined as Re number=L×V/υ, wherein: L=½×steel strip width, V=average flow rate of gas in the direction of the width of the steel strip at an edge=Q/H, Q=½×amount of gas blown on the steel strip, υ=coefficient of kinematic viscosity, and H=distance (mm) from said surface of the cooling chamber to said surface of the traveling steel strip.