Laser-powered surface marking for sheet mill roller - produces spaced laser beam impart points on turning roller, and develops craters and rims in desired pattern

摘要

The surface of a roller forming part of a sheet metal mill is irradiated by an interrupted laser beam which, as the roller is turned, develops a series of microcraters. The positioning of the craters is determined by the rate of turning of the roller, the rate of interruption of the laser beam, and the traverse rate of the laser as it moves from one end of the roller to the other. During the formation of each microcrater, a jet of reducing gas is directed obliquely at the roller surface to produce an associated ridge which partly surrounds the crater. The dimensions of the ridge are determined by the jet force and direction applied. In a subsequent phase, the ridge formed is re-melted by a subsidiary beam to ensure complete adhesion with the roller surface. The resulting pattern is transferred to any sheets rolled, improving their ductility for stamping and their receptivity to superimposed coats.