DEVICE FOR ALLOYING MOLTEN ZINC-PLATED STEEL PLATE, METHOD FOR CONTROLLING ALLOYING, AND METHOD FOR CALCULATING DEGREE OF ALLOYING

摘要

Provided is a device for alloying a molten zinc-plated steel plate, a method for controlling alloying, and a method for calculating the degree of alloying, capable of suppressing alloy nonuniformities that occur when a molten zinc-plated steel plate containing Si, Mn, or another alloyed steel is alloyed. A device for alloying a molten zinc-plated steel plate, a method for controlling alloying, and a method for calculating the degree of alloying, the device for alloying a molten zinc-plated steel plate characterized in having: a temperature measurement means (T1) on the downstream side from the alloying zone, the temperature measurement means being unaffected by the surface reflectance of a steel plate; and a radiation thermometer (T2) upstream or downstream from the temperature measurement means, which is unaffected by the surface reflectance of a steel plate, the radiation thermometer being capable of measuring the temperature in three or more locations in the width direction of the steel plate; and furthermore a heating device capable of partially adjusting the heating amount in the width direction in corresponding fashion to the temperature measurement positions of the radiation thermometer (T2) in the width direction of the steel plate in the alloying zone.