METHOD FOR CHANGING COATING WEIGHT OF HOT-DIP COATING

摘要

PURPOSE: To greatly shorten the part where the coating weight of plating before and after a target coating weight change point deviates from the permissible range of a target coating weight. CONSTITUTION: The spacing D from an injection nozzle to a steel strip is so preset that the change rateΔPij of an injection gaseous pressure P attains a prescribed value or below at the time of changing the segment region ni to nj of the target coating weight M, by which the spacing D and the change rateΔPij of the injection gaseous pressure P after the execution of the control to the injection gaseous pressure P is made smaller and the time for stabilization of the injection gaseous pressure P is shortened. The injection gaseous pressure P is controlled at the control timing Pij set according to the change of the target coating weight M, by which the control of each of the respective target coating weights is executed at the right timing even if the change rateΔPij of the injection gaseous pressure P at the time of changing the target coating weight varies.