Patent ID: 11939879
Assignee: MITSUBISHI ELECTRIC CORPORATION
Field: Machine tools (Mechanical engineering)
Classification: CPC F  B  C | IPC B  F

Claim 2:
3. A blade repair method of repairing a crack formed in a blade toward a blade body from an end surface of a platform in a blade width direction including a direction perpendicular to a blade height direction, the blade including the blade body that is disposed in a combustion gas flow channel in which combustion gas flows and has an airfoil shape and the platform that is provided at an end of the blade body in the blade height direction, extends in the blade width direction, and partitions a part of an edge of the combustion gas flow channel, the blade repair method comprising:
a notched portion-forming step of forming a notched portion, which is recessed toward the blade body from the end surface of the platform and includes a first region positioned close to the blade body and a second region positioned closer to the end surface of the platform than the first region, by removing a crack-containing region, which includes the crack, in the platform not yet repaired;
a first welding step of filling the first region with a first welding material by overlay welding using the first welding material; and
a second welding step of filling the second region with a second welding material by overlay welding using the second welding material after the first welding step,
wherein high-temperature strength of the second welding material is higher than high-temperature strength of the first welding material,
weldability of the first welding material is higher than weldability of the second welding material,
the second region is a region in a range of 1.0 mm to 3.0 mm toward the blade body from the end surface of the platform, and
in the notched portion-forming step, a penetrating portion that removes the crack by penetrating the platform in a thickness direction of the platform and a non-penetrating portion that does not penetrate the platform are formed in the first region.