| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an underwater welding method that can switch a step between a heating step and a welding step without the need for precisely adjusting a position of a lens and can stably perform a preferably reproducible welding work, and to provide an underwater welding apparatus. <P>SOLUTION: The underwater welding method for welding an underwater welding target including a crack by a weld head, uses an apparatus including: an optical element for reducing energetic density of a laser beam; and a movement mechanism for moving the optical element so as to be positioned in and outside a light path of the laser beam. The underwater welding method includes: a heating step of heating the welding target by radiating the laser beam to the welding target while positioning the optical element in the light path of the laser beam, to evaporate water from the inside of a crack; and a welding step of welding the welding target by radiating the laser beam to the welding target while positioning the optical element outside the light path of the laser beam. <P>COPYRIGHT: (C)2013,JPO&INPIT |
