| 摘要 |
PURPOSE:To uniformly and efficiently cool a thick steel plate from front end part to rear end part by guiding cooling water of slit jet at upstream side in a first step cooling zone of roller quenching apparatus to the downstream side and also cooling by water injection nozzle. CONSTITUTION:While pressing the thick steel plate 1 upward and downward by plural rolls 2 and carrying, the cooling water is injected from front and back faces of the plate 1 to cool. By this method, at the upstream side in the first step cooling zone, the slit jet cooling is executed by the slit nozzle 6 and also at the downstream side, the cooling water is guided by covers 14. In the cover 14, water injection nozzles 16 are arranged in plural lines. After colliding against the surface of plate 1 by injecting from the nozzle 6, the water is again collided to the injected cooling water from the nozzles 16, to form a dipped stirring part, which is sufficiently brought into contact with the front and back faces of plate 1 without jumping. Therefore, even at the front and rear end parts of plate 1, the formation of dipped stirring part can be maintained. |
