| 摘要 |
PURPOSE:To improve the quality control of a metal tube by irradiating a laser beam on the outer peripheral surface of a metal tube and marking an identification control mark with a specific depth. CONSTITUTION:On the outer peripheral surface of a metal tube P like titanium tube, zircalloy tube, etc., the laser beam by Q switch la YAG laser 1, in which the output is adjusted by a specific modulated frequency, or the laser by Q switch carbon dioxide gas laser is scanned and irradiated by a scanning mirror 3. By this irradiation, a surface layer part of the metal tube P is oxided in shallow depth to be blackened. Thus, the identification control mark of letters, figures, etc., with a depth of <=0.1mum on the outer peripheral surface of the metal tube P. By this means, it reduces a care for additional control in order to eliminate the mistake for lot control of tubes. |
