| 摘要 |
PROBLEM TO BE SOLVED: To provide a cooling method for a steel material which can reduce the unevenness of cooling without increasing the number of cooling water spray nozzles. SOLUTION: A cooling water nozzle 10 is equipped with a discharge port 4 formed on its tip end face 5, a first passage 1 which leads to the discharge port 4, and a second passage 2 which has a smaller cross section than the first passage 1 and leads to the discharge port 4. In a cooling zone of a hot rolling line which manufactures an H-section steel, the cooling water nozzle 10 is placed slantingly toward the inner face of the flange of the H-section steel at a place lower than the top of conveyance rollers for conveying the H-section steel so that the first passage 1 comes nearer to the inner face of the flange of the H-section steel than the second passage 2. Cooling water from the cooling water nozzle 10 is jetted to the inner face of the flange of the H-section steel so that the inner face of the flange of the H-section steel is cooled with the jetted cooling water. The cooling method comprises a step of slantingly placing the cooling water nozzle 10 toward the inner face of the flange of the H-section steel and a step of jetting the cooling water from the cooling water nozzle 10 to the inner face of the flange of the H-section steel. COPYRIGHT: (C)2006,JPO&NCIPI |
