LASER WELDING DEVICE, METHOD OF MAINTAINING REACTOR INTERNAL STRUCTURE OF NUCLEAR POWER PLANT, AND LASER PROCESSING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a powder laser welding device capable of easily welding a plant welding target facing a constricted portion and shortening time required for welding work.SOLUTION: A powder laser welding device includes: a powder laser welding head 21; and a welding head scanner. A collimator lens 25 provided in a head main body 28 of the powder laser welding head 21 is arranged to face a tip end of an optical fiber 26. The powder laser welding head 21, which includes only the collimator lens 25 as a lens, is short. A laser beam generated by a laser oscillator is guided into the optical fiber 26, incident on the collimator lens 25, and converted to a parallel beam. A parallel laser beam 28B passes through a laser passage 27, is radiated on a surface of a welding target, and fuses this surface. Metallic powder is jetted from powder supply passages 29A and 29B formed in a head main body 22 to the fused surface, thereby performing build-up welding on the surface.