SMOOTHING ROLL FOR INSPECTING SURFACE OF STEEL PLATE AND APPARATUS FOR HEATING SURFACE OF STEEL PLATE

PURPOSE: To provide a smoothing roll for inspecting the surface of a steel plate and a heating apparatus for the surface of the steel plate, on which rust preventing oil is applied, which spreads the rust preventing oil that is applied on the surface of the steel plate, on the entire surface so as to obtain the uni form surface performance suitable for the inspection of the detect of the surface of the steel plate, absorb the extra oil and make the oil film uniform. CONSTITUTION: In a roll, which absorbs the oil infiltrated into an oil- impregnated member 41 attached to the surrounding part into the inner space conducted to the outer surface of a hollow roll 40 and then discharges the oil, a heater is assembled into the inside of the above described oil-impregnated member as the feature. A heating means, which increases the temperature of the surface of the steel plate under the non-contact state, is provided at the front part of the smoothing roll 4 that is the approaching side of the steel plate. As the heating means for increasing the temperature of the steel plate under the non-contact state, any of an infrared-ray heating type, an induction heating type, an electric resistance heating type and a hot-air heating type can be used.