Abstract: An overlay welding method includes irradiating a surface of a metal member with a laser beam while supplying a weld metal powder, and performing overlay welding on the surface of the metal member, and repeatedly performing a weld bead formation step of melting and solidifying the weld metal powder with the laser beam to form a plurality of weld beads on the surface of the metal member. Each of the plurality of weld beads has one portion in a width direction overlapping each other. In the overlay welding method, in a case of forming an adjacent weld bead, which is a weld bead adjacent to a previously formed weld bead, an energy density of the laser beam is adjusted to be higher at a portion of the adjacent weld bead overlapping the previously formed weld bead than at a portion not overlapping the previously formed weld bead.

Abstract: This blade repair method has: a first welding step in which overlay welding in which a first welding material is used is performed to form a notched part and a bury a first region positioned on a blade-body side with a first welding material; and a second welding step in which, after the first welding step, overlay welding in which a second welding material is used is performed to form a notched part and bury a second region positioned on a front-surface side of a platform with the second welding material. The high-temperature strength of the second welding material is higher than the high-temperature strength of the first welding material, the weldability of the first welding material is higher than the weldability of the second welding material, and the second region is located in a range from 1.0 mm to 3.0 mm (inclusive) from the front surface of the platform toward the blade body.

Abstract: This blade repair method has: a first welding step in which overlay welding in which a first welding material is used is performed to form a notched part and a bury a first region positioned on a blade-body side with a first welding material; and a second welding step in which, after the first welding step, overlay welding in which a second welding material is used is performed to form a notched part and bury a second region positioned on a front-surface side of a platform with the second welding material. The high-temperature strength of the second welding material is higher than the high-temperature strength of the first welding material, the weldability of the first welding material is higher than the weldability of the second welding material, and the second region is located in a range from 1.0 mm to 3.0 mm (inclusive) from the front surface of the platform toward the blade body.