A bolt repair platform includes a frame and a tool module. The tool module includes a tool having a first end configured to rotationally engage a bolt. The tool module also includes an actuator disposed between the tool and the frame so that actuation of the actuator moves the tool with respect to the frame. The frame is removably disposed on the structure, and the tool is movable with respect to the frame, so that, at each of a plurality of positions, the second end of the tool is capable of engagement with a respective bolt disposed in an internal support structure of a nuclear reactor vessel.

A bolt repair platform includes a frame and a tool module. The tool module includes a tool having a first end configured to rotationally engage a bolt. The tool module also includes an actuator disposed between the tool and the frame so that actuation of the actuator moves the tool with respect to the frame. The frame is removably disposed on the structure, and the tool is movable with respect to the frame, so that, at each of a plurality of positions, the second end of the tool is capable of engagement with a respective bolt disposed in an internal support structure of a nuclear reactor vessel.

A dual walled component includes a spar comprising a plurality of pedestals; a coversheet attached to a first set of pedestals from the plurality of pedestals; and a repaired coversheet portion attached to a second set of pedestals from the plurality of pedestals and to the coversheet, where the repaired coversheet portion includes a braze material.

A method for improving the surface of an aluminum alloy article includes manufacturing the aluminum alloy article using an additive manufacturing technique, wherein the article as-manufactured includes one or more of cracks, roughness, or porosity at a surface of the article; coating the surface of the aluminum alloy article with a diffusion element, the diffusion element being capable of diffusing at least 0.2 mils into the article; heating the aluminum alloy article coated with the diffusion element to cause the diffusion element to diffuse the at least 0.2 mils into the article, thereby forming a diffusion layer of at least 0.2 mils in thickness comprising both aluminum alloy and diffusion element; and removing the diffusion layer from the aluminum alloy article, whereby upon the removing, a resulting improved surface of the article comprises fewer or smaller cracks, reduced roughness, or reduced porosity.

A method for improving the surface of an aluminum alloy article includes manufacturing the aluminum alloy article using an additive manufacturing technique, wherein the article as-manufactured includes one or more of cracks, roughness, or porosity at a surface of the article; coating the surface of the aluminum alloy article with a diffusion element, the diffusion element being capable of diffusing at least 0.2 mils into the article; heating the aluminum alloy article coated with the diffusion element to cause the diffusion element to diffuse the at least 0.2 mils into the article, thereby forming a diffusion layer of at least 0.2 mils in thickness comprising both aluminum alloy and diffusion element; and removing the diffusion layer from the aluminum alloy article, whereby upon the removing, a resulting improved surface of the article comprises fewer or smaller cracks, reduced roughness, or reduced porosity.

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.

The repair/modification method for metallic substrates according to the present invention includes: a step for preparing a metallic substrate having a first region that is divided in an in-plane direction of the substrate, the first region containing a defect and/or a structurally discontinuous portion; and a step for repairing the defect and/or modifying the structurally discontinuous portion by pressing a friction tool which does not have a probe against a top surface of the first region while rotating the friction tool so as to generate frictional heat while pressing on the top surface.

The repair/modification method for metallic substrates according to the present invention includes: a step for preparing a metallic substrate having a first region that is divided in an in-plane direction of the substrate, the first region containing a defect and/or a structurally discontinuous portion; and a step for repairing the defect and/or modifying the structurally discontinuous portion by pressing a friction tool which does not have a probe against a top surface of the first region while rotating the friction tool so as to generate frictional heat while pressing on the top surface.

A laser welding repair device includes a laser oscillator, a laser head that condenses laser light from the laser oscillator to irradiate a repair portion, a temperature sensor that detects a temperature distribution of a steel material irradiated with the laser light, and a control unit. The control unit sets a spot diameter of the laser light to be less than 3 mm, moves the laser head and enlarges a heat input area to check for a crack in the heat input area, the heat input area being formed by irradiating the steel material with the laser light, and controls the laser head to irradiate a region where a temperature detected by the temperature sensor is equal to or less than a mechanical melting temperature of the steel material. Where a welding is performed in a flat position, the crack can be easily and reliably erased without causing burn through.

A method for repairing a worn portion in an inner diameter surface of a bore of a cast iron part is disclosed. The inner diameter surface of the bore may have an original surface geometry prior to wear. The method may comprise forming a crescent-shaped pocket in the inner diameter surface of the bore to remove the worn portion, installing an insert in the crescent-shaped pocket, and post-machining the insert to form a crescent-shaped insert that is flush with the original surface geometry of the bore inner surface diameter.