The present invention is directed to in situ methods for maintaining turbine assemblies. One such method includes: disposing a maintenance apparatus on the rotor; positioning the maintenance apparatus proximate to the damaged region by rotating the rotor; and repairing the damaged region by operating a repair tool disposed on the apparatus. Another method includes: disposing a maintenance apparatus on the stator; positioning the damaged region proximate to the maintenance apparatus by rotating the rotor; and repairing the damaged region by operating a repair tool disposed on the apparatus.

A repair method of a cast steel member having a crack formed on a surface of the cast steel member includes: forming a recess having a wedge-shaped cross section that widens in a depth direction of the cast steel member by cutting the cast steel member from the surface of the cast steel member to a predetermined depth so as to include the crack; pushing and embedding a repair member made of a metal material more flexible than the cast steel member into the recess formed in the recess forming; and diffusion-bonding the repair member to the cast steel member by heating a boundary between an exposed surface.

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.

An upstream rail of a turbine engine turbine casing, which includes a casing body extending along a longitudinal axis, includes a base including a radial face, extending substantially radially from the casing body, a plate including an upper face, extending substantially along the longitudinal axis, a connection portion between the base and the plate, including a concave face connecting the radial and upper faces, the concave and radial faces extending on either side of an edge. The upstream rail is repaired through a method including covering a surface with a solder, the surface including the upper and concave faces such that the solder extends until the edge, and machining the covered surface, in a single action, in a direction toward the radial face, so as to reshape the surface, wherein the machining of the covered surface is performed on a portion of the radial face.

A method for repairing an at least externally coated hollow component. The direct mechanical machining of a coated component after use removes the need for a coating-removal and selective hollowing step and a selective repair of cracks, since a design adaptation leads to a component being engineered or used such that it can be used again as a result of external dimensional stipulations.

A system includes a gas turbine component having a recessed portion with a recessed surface in a hard-to-weld (HTW) material. The system includes a plate disposed over the recessed portion. The plate has an easy-to-weld (ETW) material. The plate has an outer surface and an inner surface, and the inner surface faces the recessed portion. The system includes a braze material disposed within the recessed portion between the recessed surface and the inner surface of the plate. The braze material is configured to bond the recessed surface of the recessed portion with the inner surface of the plate when the braze material is heated to a brazing temperature. The system includes a filler material disposed on the outer surface of the plate disposed over the recessed portion. Application of the filler material to the outer surface of the plate is configured to heat the braze material to the brazing temperature.

A method includes positioning a braze material along a defect of a component of a turbine system, positioning a cover over the braze material, and focusing a heat source on the cover to melt the braze material along the defect.

A method of furnace-less brazing of a substrate is provided. The method includes providing a substrate having a brazing region thereon; disposing braze precursor material containing a nickel powder, an aluminum powder, and a platinum group metal powder on the brazing region; and initiating an exothermic reaction of the braze precursor material such that the exothermic reaction produces a braze material that reaches a braze temperature above the liquidus temperature for the braze material. A braze precursor material is also provided.

A method of furnace-less brazing of a substrate is provided. The method includes providing a substrate having a braze region thereon; disposing braze precursor material containing a nickel powder, an aluminum powder, and a platinum group metal powder on the braze region; and initiating an exothermic reaction of the braze precursor material such that the exothermic reaction produces a braze material that reaches a braze temperature above the solidus temperature of the braze material. A braze precursor material is also provided.

Repaired rotors are provided. The rotors are repaired by using an indenter apparatus for plastically straining original portions of the rotor and adjacent repair welds. The weld nugget, adjacent heat affected zones, and the adjacent parent-metal portions or new metal portions, are indented at a weld nugget and heat affected zone, to produce threshold levels of uniform plastic strain which meet or exceed plastic strain levels that provide, when the weld nugget and heat affected zone is heat treated, a recrystallized grain structure metallurgically comparable to the grain structure of the original parent-metal of the rotor. Repaired integrally bladed rotors for gas turbine engines, such as aircraft engines, are provided. Blades for gas turbine engines, including integrally bladed rotors, may be advantageously provided, having been manufactured or repaired as described.