| 摘要 |
PURPOSE:To enable the preparation of a steel strip with an excellent shape, by shortening the contact time of heating and cooling rolls and the steel strip to eliminate temp. deviation in a width direction. CONSTITUTION:In order to attain good energy efficiency and the shortening of a furnace length in a continuous heat treating furnace, a steel strip 1 is turned around a roll 2 provided with a heating medium flow passage 8 formed by a body 5 and a core 6 in the furnace and a heating medium or a cooling medium is flowed to a discharge passage 4 from a supply pipe 3 through the aforementioned roll 2 to heat or to cool the strip material 1. By reducing the contact time of the steel strip 1 with 21 rolls to 1sec or less, temp. deviation in the width direction of the steel strip is eliminated while heat stress plastic deformation due to temp. distribution is prevented and the shape degradation of the steel strip 1 is prevented. In addition, by pressing the contact part of the steel strip 1 and the roll 2 to a width direction by other roll, the temp. deviation and coefficient of heat transmission can be improved together. |
