APPARATUS AND METHOD FOR PRODUCING RAPIDLY COOLED METAL STRIP

PURPOSE:To improve surface quality by calculating quantity for grinding a cooling roll based on outputted signal corresponding to surface roughness of a rapidly cooled metal strip with an on-line measuring instrument and arranging means for grinding the roll surface based on this signal. CONSTITUTION:By information on the surface roughness measured with the surface roughness measuring instrument 20 in on-line, the feedback is executed to rotating and scanning mechanisms for the brush roll 5 through a converter 22, comparison computing element 21 and servo-motor control unit 23 and the surface characteristic of rapidly cooled metal strip is kept to the desired condition or can be changed. In order to measure the surface roughness with the optical type instrument, it is particularly effective to utilize He-Ne, Ar, carbon dioxide gas and YAG laser beam, etc., having single wave length and extremely intensive directivity as a beam source. By this method, the surface characteristic of metal strip is kept to constant and by shifting this to the desired condition, the surface quantity can be improved.