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Assessment of the Mechanical Stress Improvement Process for Mitigating Primary Water Stress Corrosion Cracking in Nickel Alloy Butt Welds in Piping Systems Approved for Leak-Before-Break

Description: This report provides an assessment of the use of Mechanical Stress Improvement Process to reduce, or decrease, stress-driven degradation, i.e., primary water stress corrosion cracking.
Date: January 1, 2013
Creator: Sullivan, Edmund J. & Anderson, Michael T.
Partner: UNT Libraries Government Documents Department

Elastic properties of sand-peat moss mixtures from ultrasonic measurements

Description: Effective remediation of an environmental site requires extensive knowledge of the geologic setting, as well as the amount and distribution of contaminants. Seismic investigations provide a means to examine the subsurface with minimum disturbance, Laboratory measurements are needed to interpret field data. In this experiment, laboratory tests were performed to characterize manufactured soil samples in terms of their elastic properties. The soil samples consisted of small (mass) percentages (1 to 20 percent) of peat moss mixed with pure quartz sand. Sand was chosen as the major component because its elastic properties are well known except at the lowest pressures. The ultrasonic pulse transmission technique was used to collect elastic wave velocity data. These data were analyzed and mathematically processed to calculate the other elastic properties such as the modulus of elasticity. This experiment demonstrates that seismic data are affected by the amount~of peat moss added to pure sand samples. Elastic wave velocities, velocity gradients, and elastic moduli vary with pressure and peat moss amounts. In particular, ultrasonic response changes dramatically when pore space fills with peat. With some further investigation, the information gathered in this experiment could be applied to seismic field research.
Date: September 2, 1998
Creator: Trombino, C N
Partner: UNT Libraries Government Documents Department

Microstructural Effects and Signal-Enhancement Techniques in Ultrasonic Examination of Stainless Steel

Description: Ultrasonic inspection of large-grain stainless steel and stainless steel welds is difficult, and the results obtained are not easily interpreted. In the present study, the effects of stainless steel microstructure on ultrasonic test results are described, and several signal-processing techniques for enhancing ultrasonic flaw signals are discussed.
Date: September 1976
Creator: Kupperman, D. S. & Reimann, K. J.
Partner: UNT Libraries Government Documents Department

Nondestructive-Evaluation Needs for Coal Liquefaction

Description: Nondestructive-evaluation (NDE) needs for coal liquefaction have been identified by acquiring information from site visits, a literature review, and discussions with government personnel. Nondestructive evaluation has been highly rated in importance as a way to help alleviate problems in coal-conversion systems. The primary problems are associated with highly erosive and corrosive slurries being transferred throughout the coal-conversion process. Applicable NDE techniques for both pre-service and in-service inspection include high-temperature ultrasonics, acoustic emission, radiography, acoustic holography, and ultrasonic spectroscopy.
Date: 1977?
Creator: Kupperman, D. S.
Partner: UNT Libraries Government Documents Department

An Ultrasonic Scanner for Stainless Steel Weld Inspections

Description: The large grain size and anisotropic nature of stainless steel weld metal make conventional ultrasonic testing very difficult. This paper evaluates a technique for minimizing the coherent noise in stainless steel weld metal. The method involves digitizing conventional A-scan traces and averaging them with a minicomputer. Results are presented for an ultrasonic scanner which interrogates a small volume of the weld metal while averaging the coherent ultrasonic noise.
Date: September 1978
Creator: Kupperman, D. S. & Reimann, K. J.
Partner: UNT Libraries Government Documents Department

Second Mechanized In-Service Inspection of EBR-2 Steam Generator

Description: The second mechanized ultrasonic inspection of evaporation EV-702, part of the EBR-II steam-generator system, was completed in March 1978. The 2 1/2 Cr-1 Mo duplex tubes were inspected from the bore (water) side for flaws and changes in wall thickness and for evaluating the condition of the braze between the tubes. An addition to this second inspection was the use of an ultrasonic probe to search for circumferential flaws. The inspection equipment was thoroughly checked and routinely calibrated, using a reference standard containing electrical-discharge-machined notches. Notches as small as 1.6 mm long by 0.25 mm deep were readily detected.
Date: November 1978
Creator: Longua, K. J.; Whitham, G. K.; Allen, C. C. & Larson, H. A.
Partner: UNT Libraries Government Documents Department

Signal analysis approach to ultrasonic evaluation of diffusion bond quality

Description: Solid state bonds like the diffusion bond are attractive techniques for joining dissimilar materials since they are not prone to the defects that occur with fusion welding. Ultrasonic methods can detect the presence of totally unbonded regions but have difficulty sensing poor bonded areas where the substrates are in intimate contact. Standard ultrasonic imaging is based on amplitude changes in the signal reflected from the bond interface. Unfortunately amplitude alone is not sensitive to bond quality. We demonstrated that there is additional information in the ultrasonic signal that correlates with bond quality. In our approach we interrogated a set of dissimilar diffusion bonded samples with broad band ultrasonic signals. The signals were digitally processed and the characteristics of the signals that corresponded to bond quality were determined. These characteristics or features were processed with pattern recognition algorithms to produce predictions of bond quality. The predicted bond quality was then compared with the destructive measurement to assess the classification capability of the ultrasonic technique
Date: June 8, 1999
Creator: Chinn, D & Thomas, G
Partner: UNT Libraries Government Documents Department

Application of Ultrasonic Techniques for Brain Injury Diagnosis

Description: In this work, we evaluate methods for detecting brain injury using ultrasound. We have used simulations of ultrasonic fields in the head to model the phase distortion of the skull. In addition we present experimental data from the crania of large animals. The experimental data help us understand and evaluate the performance of different transducers in acquiring the backscatter data from the brain through the skull. Both the simulations and acquired data illustrate the superiority of lower-frequency (<= 1 MHz) ultrasonic fields for transcranial acquisition of signals from inside the brain. Additionally, the experimental work shows that the higher-frequency (5 MHz) ultrasound can also be useful in acquiring clean nearfield data to help detect the position of the inner boundary of the skull.
Date: September 19, 1999
Creator: Kasili, P. M.; Mobley, J.; Norton, S. J. & Vo-Dinh, T.
Partner: UNT Libraries Government Documents Department

High power ultrasonic bond strength evaluation

Description: S>Bond strength of diffusion and adhesive bonds has long remained one of the unsolved problems facing the materials testing industry. Many techniques are available for the detection of unbonds but these tend to become inaccurate when the unbonded surfaces are in intimate contact. Weak bonds in almost all cases cannot be distinguished from bends which approach base material strengths. One must usually resort to destructive testing of samples cut from production parts to obtain bond strength information. This is not the most satisfactory method from a cost and reliabilily standpoint. The accuracy of this data is also in some doubt since the cutting procedure itself may disturb the bond and the residual stress pattern of the part. The ultrasonic approach has the potential of eliminating many of the limitations of existing bond testing technlques. The system is based on the use of high power ultrasonic waves to stress the bond interface with an acoustic pressure sufflcient to break bonds of below minimum allowable strengths. Acceptable production parts may be 100% inspected with no detrimental effects. The technique, equipment, and transducers developed for this test as well as tests which indicate the feasibility of the method are described. Suggestions for further development are also included. (auth)
Date: October 1, 1973
Creator: Becker, F.L.
Partner: UNT Libraries Government Documents Department

Development of ultrasonic methods for examining stainless steel welds. Interim progress report

Description: Spurious ultrasonic (UT) signals obtained during the examination of austenitic stainless steel welds in LMFBR components have emphasized the need to develop more effective UT methods to supplement the examination processes presently employed during fabrication, and for use during subsequent in-service inspection of LMFBR plants. This interim report documents the first year&#x27;s effort on a program that was designed to investigate this problem and develop viable solutions. Sixty-eight weld samples were acquired, cataloged, and subjected to a series of ultrasonic, radiographic, and metallographic examination procedures. It was determined that although spurious UT noise signals could usually be associated with major dendritic grain growth patterns, the existence and magnitude of some of the observed noise signals could not be explained simply on the basis of dendritic microstructure. The results obtained during application of a series of ultrasonic and radiographic characterization procedures are included, in addition to photomicrographs and photomicrographic montages taken in the vicinity of numerous sites which produced ultrasonic noise signals of various amplitudes. A concurrent investigation was conducted to evaluate the performance of conventional ultrasonic examination procedures. These results are compared with the laboratory investigation results, and a brief outline of future work planned under this program is presented. (auth)
Date: November 1, 1975
Creator: Peterson, R.O.; Spanner, J.C. & Mech, S.J.
Partner: UNT Libraries Government Documents Department

Lamb-wave inspection of welds in stainless steel tubes

Description: An ultrasonic Lamb-wave inspection technique was developed for use in inspecting the gas tungsten arc (GTA) welds in small diameter stainless steel tubes for lack of penetration. The particular technique was employed because of the ability to introduce the sound into the material a distance from the weld. A conventional shear-wave technique was tried without success. (auth)
Date: December 26, 1973
Creator: Schrick, G. W.
Partner: UNT Libraries Government Documents Department

Benefits of the Multiple Echo Technique for Ultrasonic Thickness Testing

Description: Much effort has been put into determining methods to make accurate thickness measurements, especially at elevated temperatures. An accuracy of +/- 0.001 inches is typically noted for commercial ultrasonic thickness gauges and ultrasonic thickness techniques. Codes and standards put limitations on many inspection factors including equipment, calibration tolerance and temperature variations. These factors are important and should be controlled, but unfortunately do not guarantee accurate and repeatable measurements in the field. Most technicians long for a single technique that is best for every situation, unfortunately, there are no 'silver bullets' when it comes to nondestructive testing. This paper will describe and discuss some of the major contributors to measurement error as well as some advantages and limitations of multiple echo techniques and why multiple echo techniques should be more widely utilized for ultrasonic thickness measurements.
Date: February 10, 2011
Creator: Elder, J. & Vandekamp, R.
Partner: UNT Libraries Government Documents Department

Technical Letter Report Assessment of Ultrasonic Phased Array Testing for Cast Austenitic Stainless Steel Pressurizer Surge Line Piping Welds and Thick Section Primary System Cast Piping Welds JCN N6398, Task 2A

Description: Research is being conducted for the NRC at PNNL to assess the effectiveness and reliability of advanced NDE methods for the inspection of LWR components. The scope of this research encompasses primary system pressure boundary materials including cast austenitic stainless steels (CASS), dissimilar metal welds (DMWs), piping with corrosion-resistant cladding, weld overlays, and far-side examinations of austenitic piping welds. A primary objective of this work is to evaluate various NDE methods to assess their ability to detect, localize, and size cracks in coarse-grained steel components. This interim technical letter report (TLR) provides a synopsis of recent investigations at PNNL aimed at evaluating the capabilities of phased-array (PA) ultrasonic testing (UT) methods as applied to the inspection of CASS welds in nuclear reactor piping. A description of progress, recent developments and interim results are provided.
Date: July 21, 2008
Creator: Diaz, Aaron A.; Denslow, Kayte M.; Cinson, Anthony D.; Morra, Marino; Crawford, Susan L.; Prowant, Matthew S. et al.
Partner: UNT Libraries Government Documents Department

ELECTROCHEMICAL CORROSION TESTING OF TANKS 241-AN-102 & 241-AP-107 & 241-AP-108 IN SUPPORT OF ULTRASONIC TESTING

Description: This report presents the results of the corrosion rates that were measured using electrochemical methods for tanks 241-AN-102 (AN-102), 241-AP-107 (AP 107), and 241-AP-108 (AP-108) performed under test plant RPP-PLAN-38215. The steel used as materials of construction for AN and AP tank farms was A537 Class 1. Test coupons of A537 Class 1 carbon steel were used for corrosion testing in the AN-107, AP-107, and AP-108 tank waste. Supernate will be tested from AN-102, AP-107, and Ap-108. Saltcake testing was performed on AP-108 only.
Date: November 20, 2008
Creator: RB, WYRWAS & JB, DUNCAN
Partner: UNT Libraries Government Documents Department

Stress Corrosion Crack Detection on HU-25 Guardian Aircraft

Description: Several ultrasonic inspection methods were developed at the Federal Aviation Administration's Airworthiness Assurance NDI Validation Center (AANC) to easily and rapidly detect hidden stress corrosion cracks in all vertical windshield posts on the US Coast Guard (USCG) HU-25 Guardian aircraft. The inspection procedure locates cracks as small as 2.0 millimeters emanating from internal fastener holes and determines their length. A test procedure was developed and a baseline assessment of the USCG fleet was conducted. Inspection results on twenty-five aircraft revealed a good correlation with results made during subsequent structural disassembly and visual inspection.
Date: February 17, 1999
Creator: Blackmon, R.; Huffman, J.; Mello, C.W.; Moore, D.G. & Walkington, P.D.
Partner: UNT Libraries Government Documents Department

Ultrasonic evaluation of flood gate tendons

Description: Our water resources infrastructure is susceptible to aging degradation just like the rest of this country`s infrastructure. A critical component of the water supply system is the flood gate that controls the outflow from dams.Long steel rods called tendons attach these radial gates to the concrete in the dam. The tendons are typically forty feet long and over one inch in diameter. Moisture may seep into the grout around the tendons and cause corrosion. Lawrence Livermore National Laboratory is working with the California Department of Water Resources to develop advanced ultrasonic techniques for nondestructively inspecting their tendons. A unique transducer was designed and fabricated to interrogate the entire tendon. A robust,portable unit was assembled that included a computer controlled data acquisition system and specialized data processing software to analyze the ultrasonic signals. This system was tested on laboratory specimens and is presently being fielded at two dam sites.
Date: October 1, 1997
Creator: Thomas, G. & Brown, A.
Partner: UNT Libraries Government Documents Department