| 摘要 |
PURPOSE:To effectively and accurately repair weld defects and to form a sound weld zone by remelting the weld zone of a sleeve for repairing with the shallow penetration and few oxidized scales by a laser beam. CONSTITUTION:In the heat exchanger tube 1 where the sleeve 3 for repairing is inserted into a part where a damaged part is caused on a part of a tube wall, and the tube wall and the same sleeve are subjected to laser beam welding 5, when the weld defects are caused on the laser beam weld zone 5 and repairing is required, repair welding 7 is performed on the same weld zone 5 by the laser beam with nitrogen gas or gas formed by mixing <1% oxygen therein as shielding gas. |
