| 摘要 |
PROBLEM TO BE SOLVED: To prevent an occurrence of a sheet temperature incorrectness due to an overshoot or an undershoot or a sheet temperature incorrectness due to delay of a sheet temperature measured value reaching a sheet temperature target value, to require no deceleration of a furnace rate for adjusting a furnace temperature, and thereby to reliably bring the sheet temperature measured value to the sheet temperature target value.SOLUTION: When coils of which sheet temperature target values differ by &Dgr;T°C are coupled at an inlet side of a continuous annealing furnace to be continuously annealed, a sheet temperature reached value in a case where the sheet temperature target value is gradually changed at a predetermined rate is calculated in advance using a coil in which at least one condition selected from a sheet thickness, a sheet width, and a steel type is the same. When a tip of a coil having a different sheet temperature target value reaches an inlet side of a heating zone of the annealing furnace, the sheet temperature target value is instantly changed by a predetermined value &Dgr;T1°C corresponding to a difference between the sheet temperature reached value and a subsequent sheet temperature target value, and then the sheet temperature target value is gradually changed to the subsequent sheet temperature target value within the single coil. |
