| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a laser welding method which restrains recession of a weld zone and provides excellent welding quality without diminishing welding efficiency in laser butt welding using laser beam, and to provide a laser welding device therefor. <P>SOLUTION: In the invented laser welding method, a butt portion is formed by making ends of steel plates 1 and 2 butt to each other, and the butt portion is irradiated with a laser beam which is emitted from an oscillator 11 composed of a plurality of oscillation media, is transmitted by means of optical fibers 12 and is condensed by an optical system 13 so as to weld the steel plates. The laser beam is condensed so that one beam spot or two circular beam spots standing in line in the direction of the weld line are formed on the surface of the steel plates. Welding is performed by making the beam spots move along the weld line, with a relation that the total lengths L, L' and L" of the beam spots in the direction of the weld line on the surface of the steel plates are greater than the beam spot widths W, W' and W" in the direction perpendicular to the weld line. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
