The Babcock & Wilcox Company

Mcdermott Technology, Inc.

Bwxt Nuclear Operations Group, Inc.

Wayne M Latham

Daniel T MacLauchlan

Jimmy W Hancock

Paul J Latimer

Thomas Powers

Timothy A Policke

Michael O Robertson

Steven Paul Clark

Jonathan D Buttram

Aaron C Havener

Carlton E Stinnett

Thomas C Mohr

Robert S Evans

Michael J Kelly

Richard Manzini

Paul D Sheldon

Jayne Marie Grut

A method of inspecting a material includes examining a surface of a test material with an eddy current sensor and applying an X-ray fluorescence analysis to the surface of the test material at the same location at which the eddy current examination was performed.

Apparatus and method for inspection of a material

An EMAT apparatus which non-destructively tests spot welds between two sheets of metal. The apparatus includes a first EMAT coil on one sheet that acts as a transmitter for generating and transmitting an acoustic wave signal toward the spot weld, and a second EMAT coil on the other sheet for receiving the acoustic wave signal and converting the received acoustic wave signal to an electronic signal having a waveform. Electronics and a PC are used to measure at least one parameter of the waveform which is indicative of a characteristic of the spot weld.

EMATS for spot weld examination

A method of electromagnetically measuring the distance between adjacent tube elements in a heat exchanger. A cylindrical, high magnetic permeability ferrite slug is placed in the tube adjacent the spacing to be measured. A bobbin or annular coil type probe operated in the absolute mode is inserted into a second tube adjacent the spacing to be measured. From prior calibrations on the response of the eddy current coil, the signals from the coil, when sensing the presence of the ferrite slug, are used to determine the spacing between the tubes.

Eddy current measurement of tube element spacing

A method of examining a ductile iron casting to determine a percent of nodularity present in the casting uses an electromagnetic acoustic transducer (EMAT) system to determine a time-of-flight of an ultrasonic shear wave pulse transmitted through the casting at a selected location, from which a velocity of sound in the casting can be determined. The ultrasonic shear wave pulse created and sent through the casting experiences several internal reflections within the casting, and the absolute delay time for both second, T.sub.DELAY1, and third, T.sub.DELAY2, multiple reflections are used to determine the time, T.sub.DELTA, required for the ultrasonic pulse to travel through twice the thickness, t, of the casting at said location. The velocity, V.sub.SHEAR, of the ultrasonic shear wave pulse through the casting is calculated from T.sub.DELTA and a measurement of the thickness, t, of the casting at the location being inspected. The percent of nodularity of the casting is determined from a pre-established relationship between the calculated shear wave velocity, V.sub.SHEAR, and the percent of nodularity for ductile cast iron.

EMAT measurement of ductile cast iron nodularity

A device for measuring a load on a part and for monitoring the integrity of the part such as a bolt, comprises a socket having walls defining an interior space wherein the socket engages the bolt for transmitting a load to the bolt. An electromagnetic acoustic transducer comprising a magnet and a coil is located in the interior space of the socket near the bolt. The coil provides a current while the magnet provides a magnetic field such that the magnet and the coil generate an ultrasonic signal within the bolt. A detector is used to detect and measure a change in the ultrasonic signal at the bolt for measuring the load on the bolt and for detecting any flaws in the bolt.

Fastener characterization with an electromagnetic acoustic transducer

A shield for an electromagnetic acoustic transducer (EMAT) has multiple layers of electrically insulating and electrically conductive materials which contain a coil of the EMAT. A first insulating layer lies directly on top of the coil and is attached thereto by a suitable layer of non-conductive adhesive. A second layer having both insulating and conductive portions is provided on a side of the coil opposite the first insulating layer such that the coil is completely encapsulated within and in direct contact only with the insulating portions of the first and second layers. The insulating portion of the second layer has a high electrical resistance. A third, conductive layer having a conductive adhesive side is provided in contact with the conductive portion of the second layer. The third layer is also provided with a window extending completely therethrough having dimensions coextensive with those of the coil; shielding of the coil itself by this third layer is thus prevented. Finally, a fourth insulating layer preferably made of a thin layer of ultrahigh molecular weight polyethylene or similar insulating material is attached to the underlying third, conductive layer by adhesive means. An alternative shield and coil arrangement is also disclosed, wherein the coil is etched on one side of a substrate and a corresponding shield configuration is etched on the other side, resulting in an integrated shield and coil assembly for use in an electromagnetic acoustic transducer.

EMAT with integral electrostatic shield

An apparatus and method for scanning the outer profile of control rods in a control rod assembly includes a plurality of rotatably mounted ultrasonic transducers which are mounted for rotation about the axis of at least some of the control rods in the assembly. The assembly is moved in a linear path parallel to the axis of the control rods, past the rotating transducers for scanning the surfaces of the control rods in helical paths. By distributing the transducers in a selected configuration, all control rods in the assembly can eventually be scanned.

Ultrasonic profilometry system for control rod wear

A method for inspecting the surface of a workpiece for the presence of flaws using a ferrofluid as a penetrant which is applied to the surface of the workpiece and then scanning the surface of the workpiece with electrical detection means placed adjacent to the surface for providing responses indicative of the presence of flaws in the surface of the workpiece. If desired, a magnetic field can be used to induce the flow of the ferrofluid into any flaws prior to inspection, and for post-inspection cleanup as well. By the use of a ferrofluid, the sensitivity of the electrical detection means, advantageously of the eddy current type, is enhanced in typical applications, and also allows the use of an eddy current probe to inspect workpieces made of nonconductive and/or nonferromagnetic materials.

Growing community of inventors

Forest, VA, United States of America

Wayne M Latham