METHOD OF REPAIRING ROTOR BLADES FOR POWER GENERATION GAS TURBINES AND REPAIRED TURBINE ROTOR BLADE

摘要

A method comprising the steps of preparing replacement parts in advance for repairing damaged rotor blades, cutting out, in the case of a rotor blade being damaged, the damaged portion into the same shape as that of a replacement part in such a manner as to include the damage place, and joining the replacement part to the cut-out surface of the rotor blade by welding. At this time, the shape of the replacement part and the cut-out shape of the damaged portion are so set that one portion of the cut-out surface of the rotor blade crosses some of a plurality of cooling flow paths while the other portion of the cut-out surface of the rotor blade passes in parallel with the plurality of cooling flow paths and within one wall disposed between the cooling flow paths, and a plurality of cooling flow paths are formed in the replacement part. Further, the openings of the plurality of cooling flow paths which open in the cut-out surface of the rotor blade and the openings of the plurality of cooling flow paths which open in the joined surface of the replacement part are made greater in diameter than each cooling flow path. This facilitates repairing, increases operating efficiency in repairing, shortens the repairing period, and saves repairing costs. Further, there is no possibility of the cooling flow paths in the interior being blocked or narrowed in the course of repairing, so that proper cooling can be effected also after repairing.