Abstract: A local environmental cell for a welding spray gun includes an annular ring having a top surface and a bottom surface, wherein the annular ring is adapted for attachment to an outer perimeter of the spray gun; and a plurality of fluid passageways radially disposed about the annular ring having a plurality of openings in the bottom surface of the ring in fluid communication with a vacuum source for providing a vacuum thereto. The use of the local environmental cell permits deposition of local bond coats as well as minimizes the number of steps associated with welding repair processes. For example, the use of the local environmental cell permits welding and formation of a low oxide bond coat during the welding process, thereby eliminating the need for placing the substrate subsequent to a welding process in a separate spray cell to deposit the bond coating.

Abstract: A method for protecting an article from degradation, and a method for in-situ repair of a component of an assembly are presented, wherein the method for protecting comprises providing a substrate; providing a Plasma Transferred Arc (PTA) apparatus; setting the PTA apparatus to operate in a non-transferred arc mode; and disposing at least one coating on the substrate using the PTA apparatus in the non-transferred arc mode. The method for in-situ repair comprises providing a substrate, the substrate comprising a component of an assembly and coupled to the assembly; providing a PTA apparatus; welding the substrate using the PTA apparatus in a transferred arc mode to form a welded region on the substrate; setting the PTA apparatus to operate in a non-transferred arc mode; and disposing at least one coating on the welded region of the substrate using the PTA apparatus in the non-transferred arc mode, wherein the PTA apparatus is operated using a pilot arc power supply to dispose the at least one coating.

Abstract: A shroud for a welding torch includes a hydrophilic skirt supported by a frame. The skirt is soft and pliable when wet and is self protected from the heat of welding by the water absorbed therein. The frame supports the skirt around the weld site and permits a good seal with the workpiece for excluding water during the welding process.

Abstract: A shroud for a welding torch includes a hydrophilic skirt supported by a frame. The skirt is soft and pliable when wet and is self protected from the heat of welding by the water absorbed therein. The frame supports the skirt around the weld site and permits a good seal with the workpiece for excluding water during the welding process.

Abstract: A wetting balance includes a load cell for suspending a specimen above a crucible containing a molten braze pool. A lift supports the crucible for vertical lifting thereof to effect an immersion cycle of the specimen in the pool. A controller operates the lift and determines first contact with the pool by measuring force changes thereat and produces a measured force log during the immersion cycle. In operation, the lift is operated for a predetermined time following first contact for immersing the specimen to a predetermined depth in the pool.

Abstract: A double cantilever beam (DCB) assembly is disclosed, comprising a fracture specimen having a notch which defines first and second spaced, substantially parallel, outwardly extending beams, terminating at a closed end where crack growth occurs and extending to an open end. The beams are connected to each other along at least a portion of a facing surface of each beam by two, substantially parallel ligaments, spaced from each other on the facing surfaces of the beams. Another disclosed embodiment is a corrosive environment measuring apparatus, comprising a double cantilever beam assembly disposed in an aqueous portion of a reactor vessel, and including the features described above. The reactor vessel is often a constituent of a nuclear reactor, and the DCB assembly is often disposed in a tube which is selectively lowered into the aqueous portion of the reactor vessel. The tube is usually a local power range monitor tube.

Abstract: A water exclusion device for underwater arc welding comprises a chamber having flexible gas permeable surface contact member at the lower end. A wire mesh material is the preferred gas permeable material.

Abstract: Stress corrosion cracking damage to stainless steels and nickel base superalloys is repaired by underwater plasma transferred arc welding which under conditions which reduce residual tensile stresses in the weld and adjacent portions of the repaired structure.

Abstract: Compressive residual stresses can be developed by underwater plasma transferred arc welding. The development of these compressive stresses act to prevent hot cracking and He embrittlement that can develop during welding or stress corrosion cracking that can develop subsequent to the welding operation.

Abstract: Persistent compressive stresses sufficient to suppress hot cracking, reheat cracking and stress corrosion cracking are developed in welds containing alloys of plural materials by quenching of the weld after onset of solidification but while the weld remains soft or "mushy" at a temperature above the melting point of eutectic alloys which may form. Control of the time of quenching is preferably established during submerged welding by a cup-shaped exclusion fitting which is sized relative to the dimensions of a molten weld pool and the speed of travel of a welding heat source such as a plasma transfer arc torch. The cup-shaped exclusion fitting provides improved protection of the weld and heat source with inert gas supplied thereto while also permitting submerged welding at higher hydrostatic pressures than has heretofore been possible.