Electric Power Research Institute Incorporated

The Ohio State University

Gregory J Frederick

Artie Gene Peterson, Jr

David Wayne Gandy

Shane J Findlan

Wylie J Childs

Ramaswamy Viswanathan

J Darryl Baucom

Jan T Stover

Sudarsanam Suresh Babu

Kent Coleman

James W Hales

Robert Jeffery Lowery

William Frederick Newell, Jr

John Albert Siefert

Michael L Newman

Russell G Keanini

Ryan Thomas Smith

Lou Lherbier

Andrew McGehee

Tapasvi Lolla

David Novotnak

Richard M Tilley

Artie G Peterson

A strain-hardenable stainless steel alloy includes hard secondary phases dispersed in an austenitic primary phase, the alloy including 0.3-0.6% nitrogen by weight.

Cobalt-free, galling and wear resistant austenitic stainless steel hard-facing alloy

Accordingly, the present invention provides a method for joining metallic members, which can be used to join component sub-assemblies. Further, the present invention provides a method for repairing a component by replacing a damaged portion and re-inserting a replacement section. In general, the present invention provides in one embodiment a method for joining metallic members comprising: preparing a surface of a first metallic member, thereby providing an oxide-free surface; preparing a surface of a second metallic member, thereby providing an oxide-free surface; applying pressure to the first and second metallic members, thereby forcing the surface of the first metallic member and the surface of the second metallic member together and forming a joint area; sealing an outer edge of the joint area; and subjecting the members to a hot isostatic process operation.

Method to join or repair superalloy hot section turbine components using hot isostatic processing

A method of repairing a metallic component, such as a superalloy turbine blade or turbine nozzle, includes the step of preparing the component by stripping the protective coatings from the component. The component is then pre-conditioned for welding by a first hot isostatic process. Once the conditioning sequence is complete, the component is welded using any of a number of welding techniques and by adding weld fillers to the weld area. After the welding step, the component is sealed by a second hot isostatic process treatment performed at conditions similar to the first hot isostatic process. The component is finally prepared for re-entry into service.

Method and apparatus for repairing superalloy components

A method, an apparatus ( ), and a prefabricated replacement tube ( ) are provided for repairing a defect ( ) in a tube ( ), such as in a waterwall ( ). In the method, a replacement tube ( ) is prefabricated having a wall ( ), a central opening ( ) extending through a portion thereof, and a predetermined length. A length of the tube ( ), including the defect ( ), equal to the predetermined length is removed. The replacement tube ( ) is positioned between stubs ( ) of the tube ( ), and a rotatable torch ( ) of an automated welding apparatus ( ) inserted through the opening ( ) to align with a joint between an end ( ) of the replacement tube and a stub ( ). The torch ( ) is rotated to join it to the stub ( ) along the entire joint. The torch ( ) is then removed, turned 180 degrees, and reinserted to weld the remaining joint. Optionally, the replacement tube ( ) is held in position before welding by slip rings ( ) which are slid down to cover the joints.

Method and apparatus and prefabricated replacement tube for localized waterwall repair

A method of repairing a metallic member, such as a superalloy turbine blade, includes the step of preparing the blade by stripping the protective coatings from the blade. The blade is then pre-conditioned for welding by a first hot isostatic process. Once the blade conditioning sequence is complete, the blade is welded using a laser welding technique and by adding weld fillers to the weld area. After the welding step, the blade is sealed by a second hot isostatic process treatment performed at conditions similar to the first hot isostatic process. The blade is finally prepared for re-entry into service.

Apparatus and method of repairing turbine blades

A method of repairing a substrate includes the step of excavating a well in the substrate with an electrical discharge machining operation. A wire is then delivered to the well. Simultaneously, laser energy is routed to the well such that the laser energy intersects with the wire to produce a reconstruction weld in the well. A tool delivery system with an electrical discharge machining tool head and a reconstruction welding tool head is used to perform the excavation and welding operations.

Apparatus and method for precision excavation and welding of thick-walled components

An apparatus for underwater welding has a housing and a diverter. The diverter is inside the housing and has an outer sheath and an inner sheath. A gap between the housing and diverter passes a screening fluid to form an outer screening jet that prevents water from flowing into a weld site near the electrode. The inner sheath forms a pair of channels in the inner diverter. One channel passes a shielding fluid that shields the weld site. The other channel forms an exhaust line for venting the weld site during welding.

Apparatus and method for creating dry underwater welds

A laser welding apparatus for clad welding the interior surface of a tube includes a rotating sleeve that encloses a fiber optic cable. A stationary laser generates light energy for the welding operations performed by the rotating sleeve. An optical coupler is positioned between the stationary laser and the rotating sleeve. A fixed optical assembly of the optical coupler receives light energy from the stationary laser and produces collimated and focused light energy. A rotating cable interface assembly of the optical coupler receives the collimated and focused light energy from the fixed optical assembly and applies it to the fiber optic cable of the rotating sleeve, which delivers the light energy to the interior surface of a tube so that it may be used to produce a clad weld. The fixed optical assembly includes axial and concentric alignment devices. The rotating cable interface assembly includes concentric alignment means and a monitoring cavity to provide optical feedback regarding the alignment between the fixed optical assembly and the rotating cable interface assembly. The rotating cable interface assembly may be constructed to include a safety fiber optic with an accompanying safety fiber optic photocell which is used to assess whether excessive light energy from the laser is being used.

Rotating fiber optic coupler for high power laser welding applications

A method of forming a clad weld on the interior surface of a tube includes the step of delivering a rotating filler metal wire to a selected weld location on the interior surface of the tube. The filler metal wire is synchronously rotated with a fiber optic cable which directs laser energy to the selected weld location. This results in the fusing of the filler metal wire to the interior surface of the tube to produce a clad weld within the tube.

Method of forming a clad weld on the interior surface of a tube with a

A laser welding apparatus for clad welding the interior surface of a tube is disclosed. The apparatus includes a rotating sleeve positionable within the tube. Located within the rotating sleeve is a fiber optic cable and a filler passage. The fiber optic cable receives laser energy from a laser. The filler passage receives filler material from a filler metal delivery system that synchronously moves with the rotating sleeve. Positioned at the end of the rotating sleeve is a welding head which includes a head aperture and a laser energy directional modification assembly. The laser energy from the fiber optic cable is transferred through the laser energy directional modification assembly and through the head aperture to a selected weld location on the interior surface of the tube. The filler metal from the filler metal delivery system is also conveyed through the head aperture and intersects with the laser energy at the selected weld location. The filler metal fuses with the interior surface of the tube to produce a clad weld.

Rotating apparatus for repairing damaged tubes

A flux formulation particularly suited for underwater wet flux-cored arc welding of nickel-based and austenitic stainless steels, such as internals of reactor pressure vessels, is free of halogen-containing components and has the following composition:

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Harrisburg, NC, United States of America

Gregory J Frederick