| 摘要 |
PURPOSE:To control the openings of ventilation dampers so as to make the temperature of a charged bar material to be a set temperature, and to obtain a bar material of alloy steel free from deposited bainite, by providing plural ventilation dampers and thermometers to an upper slow-cooling cover located above a cooling bed, and providing a lower slow-cooling cover to the underside of a material to be cooled. CONSTITUTION:An upper slow-cooling cover 14 is installed, which is movable in the advancing direction of a material to be cooled along a rail 15 of a cantilever beam 16 stretched over a cooling bed. Next, plural ventilation dampers 9 are provided to the cover 14, and thermometers 10, 11 for a steel material are provided to the inlet and outlet sides of the material 1. And a control device 20 of cooling is installed, which operates the dampers 9 basing on the inputs Ti, To from the thermometers 10, 11 and the inputs Ti, To from a temperature setting device 19 which sets the cooling temperature of the steel material to a prescribed value. Furthermore, a lower cooling cover 18 is provided to the underside of the material 1. |
