| 摘要 |
PURPOSE:To obtain method and apparatus for repairing machines in a reactor in which the cracking is prevented when a metal material irradiated with neutrons is welded or subjected to laser fusion while retarding subsequent cracking. CONSTITUTION:A predetermined region of a metal material irradiated with neutrons in the internal structure 2 of a pressure vessel is heated for a predetermined time at a temperature between the migration starting temperature of lattice vacancy and the melting point, e.g. a temperature at which a lattice vacancy migrates and no He bubble is formed in crystal grain boundary, thus discharging He. Subsequently, welding or laser fusion is effected thus preventing the cracking at the time of heat input and retarding subsequent cracking. Furthermore, the welded region is subjected to surface reforming, e.g. laser fusion or noble metal coating, thus preventing the corrosion resistance from lowering due to a Cr rich deposition. |
