Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A body of sensitized stainless steel is afforded passivity for exposure to a corrosive environment by an integral surface region of normalized stainless shell formed in situ by laser beam scanning.