摘要 |
PURPOSE:To make possible the generation of tight coiling flaw to be effectively prevented, by previously adjusting the radial temperature distribution of the cold rolled coil after the tight annealing treatment, so as to make the temperature of inner circumference of the coil not to be lower than that of outer circumference, and then, by carrying out the skinpass rolling. CONSTITUTION:The thermal conductivity of the coil in the direction of breadth is several to ten and several times or so larger as compared with that in the raidal direction. As a result, it is necessary to protect the end face of the inner circumferential part of the coil from contact with the wind, on purpose to uniformize the temperature distribution over the outer and inner circumference of the coil. Accordingly, when the coil 1, which was treated by the tight annealing, is to be cooled to a temperature suitable for the skinpass rolling, under a condition that several coils are being piled up, the opening facing to the inner circumferential part of the coil, in the path 10 formed by convector plates 5-7, is covered by the wind-baffle- plate 11. Hereby, the wind blown in from the center of bottom convector plate 5 flows radially from the center to outer circumference as shown by arrow mark. According to this method, almost uniform temperature distribution over inner and outre circumference of the coil can be obtained, and the tight coiling flaw usually generated during skinpass rolling can be prevented. |