Patent ID: 9459220
Filing Date: 2016-10-04
CPC Classification: C23C,G01J,G01N

Claim Text:
1. An alloyed position determining method comprising: a step for measuring, by each of a plurality of radiation thermometers, radiance of a steel sheet at positions at which the radiation thermometers are installed, the radiation thermometers being installed along a conveying direction of the steel sheet in a heat holding zone in a hot dip galvanizing line of the steel sheet, the radiation thermometers measuring radiance of the steel sheet conveyed; a radiance information acquiring step for acquiring, by a processor, information regarding a result of the measurement of radiance from each of the plurality of radiation thermometers; a steel sheet temperature estimating step for estimating, by the processor, steel sheet temperatures at the installation positions of the radiation thermometers by use of information regarding a temperature decreasing pattern of the steel sheet, accompanied by a position change in the conveying direction in the heat holding zone, and information regarding the installation positions of the radiation thermometers; an emissivity calculating step for calculating, by the processor, emissivity at the installation positions of the radiation thermometers by use of the estimated steel sheet temperatures estimated at the installation positions of the radiation thermometers and the information regarding the result of measurement of radiance; and an alloyed position determining step for determining, by the processor, an alloyed position of the steel sheet in the heat holding zone based on the calculated emissivity; wherein the information regarding the temperature decreasing pattern indicates a relationship between the installation positions of the radiation thermometers and a rate of temperature decrease, and is one of information stored in a storage unit for each manufacturing condition on the basis of past performance data or information in which results of heat transfer model simulation regarding extracted heat from the steel sheet due to an atmosphere in a furnace and an inner wall is stored in a storage unit.