General Electric Company

Electric Power Research Institute Incorporated

Harvey Donald Solomon

Robert Anthony Fusaro, Jr

Raymond Alan White

Gerald M Gordon

William R Catlin

Daniel Weinstein

Harvey E Cline

Thomas R Anthony

Paul A Siemers

Thomas Pompilio Diaz

Peter Louis Andresen

Robert H Ettinger

William D Miller

Leslie Homer String

Gary W Contreras

Ronald E De Lair

Ronald Edward Delair

Ronald Edward DeLair

Karen Kettler Denike

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.

Coating apparatus and processes for forming low oxide coatings

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.

Conforming welding torch shroud

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.

Self-immersing wetting balance

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.

Double cantilever beam crack growth sensor

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.

Water exclusion device for underwater welding

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.

Stress corrosion crack repair by plasma arc welding underwater welding

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.

Method for developing residual compressive stress in stainless steel and

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. An improved apparatus for transport of powdered welding materials provides for bleeding off of a portion of a flow of transport gas used to transport the powdered materials and can thus provide a reliable supply of such materials over increased distances and against increased gas pressures without compromising the welding heat source or the quality of the weld.

Underwater welding

An apparatus and method for inducing and measuring crack growth in a solid by using a double cantilever beam assembly which includes a fracture specimen with a notch that defines a pair of spaced outwardly extending beams terminating at an end where growth of a crack occurs, and a spring assembly for continuously urging the spaced beams apart with a substantially constant pressure that creates a spreading pressure at the end where crack growth occurs to stress the fracture specimen at the end. An electromagnet assembly is used to cyclically apply and remove the spreading pressure caused by the spring assembly.

Active stress specimen using an electromagnet and belleville washer

An apparatus and a method for measuring and controlling the crack growth rate within a double cantilever beam type test specimen. The arms of the test specimen are fitted with a pressure-actuated bellows to induce a predetermined load and with a sensing assembly to provide feedback on the amount of beam displacement resulting from application of that load. In this manner a loaded test specimen may be remotely mounted and adjusted inside the reactor pressure vessel or piping of a nuclear reactor in order to maintain a stress intensity which is constant or which varies in a predetermined manner for inducing stress corrosion cracking or corrosion fatigue in the specimen.

Method and apparatus for controlling the load on double cantilever beam

An apparatus and method for monitoring corrosion to members within the core of a nuclear reactor, particularly fuel rod cladding. A sensor means is submerged inside the core of a nuclear reactor near the member or fuel rods. The sensor means is comprised of a generally cylindrical section having an outer surface that is subject to corrosion and radiation, and has a cross-sectional area A.sub.1. The sensor means additionally has a reference section subjected to radiation but not to corrosion, and having a cross-sectional area A.sub.2. At least one pair of first probes, separated by a length L.sub.1, is placed in electrical contact with the cylindrical section. At least one pair of second probes separated by a length L.sub.2, is placed in electrical contact with the reference section. A current is passed throughout the sensor means to produce a potential gradient in the cylindrical section and reference section. The change in potential in the reference section, and the cylindrical section is measured and used to calculate the subsequent cross-sectional area in the cylindrical section between the first probes. Preferably, the cylindrical section and reference section are made from the same material as the member.

Method for monitoring corrosion on a member in a nuclear reactor core

An apparatus and method for monitoring corrosion to members within the core of a nuclear reactor, particularly fuel rod cladding. A sensor means is submerged inside the core of a nuclear reactor near the member of fuel rods. The sensor means is comprised of a generally cylindrical section having an outer surface that is subject to corrosion and radiation, and has a cross-sectional area A.sub.1. The sensor means additionally has a reference section subjected to radiation but not to corrosion, and having a cross-sectional area A.sub.2. At least one pair of first probes, separated by a length L.sub.1, is placed in electrical contact with the cylindrical section. At least one pair of second probes separated by a length L.sub.2, is placed in electrical contact with the reference section. A current is passed throughout the sensor means to produce a potential gradient in the cylindrical section and reference section. The change in potential in the reference section, and the cylindrical section is measured and used to calculate the subsequent cross-sectional area in the cylindrical section between the first probes. Preferably, the cylindrical section and reference section are made from the same material as the member.

Sensor for monitoring corrosion on a member in a nuclear reactor core

A method is provided for measuring crack growth in a solid comprising a sensor utilizing potential or voltage drop measurements across a preformed and propagating crack. Preferably the sensor is representative of a structural component and is exposed to an aggressive environment like that in which the structural component operates. Measured voltage values are plotted versus a distance at which the voltages are measured by a plurality of pairs of probes, and intercept values are obtained and used in combination with previously measured crack lengths in calculating subsequent crack lengths of a propagating crack.

Method for calculating crack lengths of conductive sensors

The yield strength and tensile strength of a duplex stainless steel alloy body are substantially increased and its anisotropy is substantially reduced by heating it until it is completely ferritic or nearly so and then aging it to cause fine austenitic precipitates to form throughout the body.

Method of making high strength duplex stainless steels

A plasma or flame spraying method is provided for applying a ceramic or metallic UV sensitive indicating coating onto a metal substrate. Particle size control of the ingredients used in the plasma or flame sprayable mixture has been found to enhance the fluorescence of the resulting indicating coating.

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Schenectady, NY, United States of America

Harvey Donald Solomon