| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To suppress/prevent failures of causing weld defects due to weld metal being blown off during jetting of residual moisture in performing repair welding by a laser beam underwater. <P>SOLUTION: In a manner covering with a curing plate 3 the surface of a metallic structure 2 including a part to be repaired, the curing plate 3 is welded underwater to the structure 2. The welding is performed underwater by laser beam welding on the circumference of the curing plate 3 while an inert gas 10 is supplied to the weld zone, so that the part to be repaired is hermetically sealed with the curing plate 3. The inert gas 10 is supplied to the weld zone coaxially with the laser beam 7 during the laser beam welding. The curing plate 3 is preliminarily provided with an opening for releasing vapor generated from water remained between the curing plate 3 and the structure 2 during the welding, wherein the opening is sealed after the curing plate 3 is welded in the circumference to the structure 2. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
