INTERGRANULAR OXIDATION DETECTING APPARATUS AND INTERGRANULAR OXIDATION DETECTING METHOD

摘要

PROBLEM TO BE SOLVED: To provide an intergranular oxidation detecting apparatus and an intergranular oxidation detecting method for determining whether an intergranular oxide is present on the surface of a hot-rolled steel sheet after acid cleaning.SOLUTION: An intergranular oxidation detecting apparatus according to the present invention for a hot-rolled steel sheet after acid cleaning includes: a first radiation thermometer; a second thermometer capable of measuring the temperature of the hot-rolled steel sheet after acid cleaning irrespective of the thermal emissivity; and a mechanism for determining whether an intergranular oxide is present on the basis of the temperature measured with the first radiation thermometer and the temperature measured with the second thermometer, and an intergranular oxidation detecting method according to the present invention for a hot-rolled steel sheet after acid cleaning includes: measuring a first temperature of a hot-rolled steel sheet after acid cleaning with a first radiation thermometer; measuring a second temperature of the hot-rolled steel sheet after acid cleaning with a second thermometer capable of measuring the temperature irrespective of the thermal emissivity; and determining whether an intergranular oxide is present on the basis of the first temperature and the second temperature.SELECTED DRAWING: Figure 1