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Simplified NDE of a crack in a pipe weld by means of the potential drop technique
N DT Abstracts various kinds. Of these heavily inspected areas, the welds definitely generate the greatest number of non destructive examinations (NDE). These examinations generally require very heavy developments and investments, which however must remain compatible with two considerations tending to be opposite to each other : the constructor’s or the owner’s productivity on the one hand, and the safety of the installation on the other hand. In all cases, the stages proceeding the application of an examination procedure must refer to an analysis based on the integrity of the weld during the fabrication and operation of the component. The ideal way to evaluate the confidence one can grant to any examination diagnostics, rests on the experimentation with mock-ups. These mock-ups must accurately represent the geometrical and metallurgical structures, and the nature of likely defects. 58506 Chelladurai. T.; Sankuranarayanan, A.S.; Acharya, A.R.; Krishnamurthy, R.
Acoustic emission response of 18% Ni maraging steel weldment’ with inserted cracks of varying depth to thickness ratio Materials Evaluation, Vol. 53, No. 6, pp. 742-746 (Jun. 1995) Acoustic emission studies have been carried out on a batch of welded and centre cracked specimens made of 18% Ni M250 maraging steel where the crack depth to specimen thickness ratio varied from approximately IO/80 to 25/80. The paper brings out the AE performance of the specimens with inserted surface cracks of different sizes when the latter become critically severe leading to failure. The studies indicate the predictions possibility for the hardware constructed out of this material reasonably well before their final rupture. The AE signatures are also presented in a form that would facilitate generation of an acceptance criteria for the evaluation of hardware in real time. 58498
Fang, C.K.; Kannatey-Asibu, E.; Barber, J.R.
Acoustic emission investigation of cold cracking in gas metal arc welding of AISI 4340 steel Welding Research, Vol. 74, No. 6, pp. 177s- 184s (Jun. 1995) Acoustic emission (AE) has been used to investigate the propagation of a finite crack in a weldment subjected to nonuniform longitudinal residual stresses during gas metal arc welding (GMAW). Cold cracking in selected weldments was accelerated using the electrochemical method to cathodically charge the weldments with hydrogen in order to induce hydrogen embrittlement. The envelopes for both spectra were found to decrease with increasing frequency, while the fluctuations in each curve diminished at high Frequencies.
57808
Skubis, J.; Jezierski, G.; Ranachowski, J.
Wade Edens, C.
Hill, E.v.K.; Knotts, G.L.
The acoustic emission (AE) flaw growth activity was monitored in aluminum-lithium weld specimens subjected to tensile loading. From an initial set of three specimens it was found that the tensile load associated with the peak of the AE events versus load curve could be.correlated directly with the ultimate load that the specimen would carry. This correlations was found to exist at loads less than or equal to 50% of the specimen’s ultimate load. Thus, an ultimate load prediction equation was generated. This technique was then applied to predict ultimate strengths in a second set of twelve specimens.
of 13 HMF steel and the results of simultaneous measurements of the acoustic emission generated during tension. The second part of the article discusses fhe results of measurements of the acoustic emission generated in the welds during heat treatment. The authors present a detailed discussion of heat treatment processes, the measurement system used in process conditions, and numerical methods for recording and analyzing the results.
57273
Saks, M.; Hara, K.; Abe, H.
Topp; Hughes; Michaels; Laenen
The use of ACFM during space flight and its application to more general weld inspection 6th European Conference on Non Destructive Testing, Nice (France), 24- 28 Oct. 1994. Vol. 1. pp. 5 13-5 18. ECNDT (1994) The alternatingcurrent field measurement (ACFM) inspection technique
Simplified NDE of a crack in a pipe weld by means of the potential drop technique Series A - Mechanics
This paper describes a multi-element, eddy current array for the local testing of ferritic specimens including welds. A novel transient method is used to extract coil impedance parameters, and has the advantage of fast measurement, digital compatibility and a minimum of front-end components; a useful feature when large element numbers are involved. The problem of displaying lift-off and flaw information from an array is solved by using a novel ‘volcano display’, which provides a simple two-dimensional image of conditions under the array.
Predicting ultimate strengths of aluminum-lithium (AI-Li) welds using acoustic emission ASNT 1993 Spring Conference and 2nd Annual Research Symposium, Nashville, Tennessee (United States), 29 Mar. -2 Apr. 1993. pp. 81-83. ASNT (1993) ISBN o-931403-13-8
Measurements of the material characteristics and the acoustic emission of a 13 HMF steel weld (In Polish) Polish Academy of Sciences, Warsaw (Poland) N95-10246/3/GAR, 114pp. (1992) This article describes the current status of research on an acoustic emission method for detecting material defects in welds of steel pipes made of 13 HMFsteel. The authors present the tension characteristics of samples
Journal
58261 McNab, A.; Thomson, J. An eddy current array instrument for application on ferritic welds NDT & E International, Vol. 28, No. 2, pp. 103-l 12 (1995)
Not since Bram Stoker’s “Dracula” has there been such interest generated in pressure vessel integrity. Coiled tubing is coming on strong as an alternative to jointed tubulars (tubing and drill pipe) used in the conventional workover unit. Several companies have either produced new wells or performed re-entry successfully into existing wells using coiled tubing. Manufacturers of coiled product are extending research into and some cases are now promoting coiled tubing “drilling pipe” performing at pressures exceeding 10,000 PSI with yield strength of 100,000 PSI. These increased performance levels now demanded of coiled tubing will require a closer nondestructive evaluation of the skelp.
Journal of Acoustic Emission, Vol. 12, No. 3-4, pp. 111-l 15 (Jul.-Dec. 1994) Acoustic emission studies have been carried out on a batch of center cracked M250 maraging steel welded specimens, having crack depth to specimen thickness ratio of 0.15 to 0.17. Broad-band AE sensors with 100-360 kHz bandpass filter have been employed for the experiments. The studies promise the prediction possibility for the hardware constructed out this material well before their final rupture and hence can facilitate generation of suitable acceptance criteria for the evaluation of hardware in real time.
JSME International
(Feb. 1992) The prototype of a testing devise for the nondestructive detection and identification of defect location and dimensions in a piping, especially of cracks in welded joints, has been evaluated on a laboratory scale. For a variety of reasons, it was not possible yet to perform trials in an industrial-scale system, as eg. in a power plant pipe system or the like.
Coiled tubing: early warning system to detect flaws in flat sheet prior to rolling and welding 1993 International Chemical and Petroleum Industry Inspection Technology III, Topical Conference, Houston, Texas (United States), 14- 16 Jun. 1993, pp. 20-24. ASNT (1993) ISBN O-931403-15-4
Acoustic emission response of centre cracked M250 maraging steel welded specimens
58468
58333 Wuensch, W. Design and testing of equipment for nondestructive detection and identification of the location and dimensions of materials defects, especially of cracks in welded joints of pipe systems (In German, English abstract) und Naturschutz fuer Umwelt, Bundesministerium Reaktorsicherheit, Bonn (Germany), TIB/B94_02356/GAR, 196pp.
57843
58493 Chelladurai, T.; Sankaranarayanan, AS.; Purushothaman, K.K.
58490
inner surface of a welded pipe. The pipe is welded circumferentially and the crack exists vertically to the inner surface at the weld. Potential drop is measured on the outer surface of the pipe. The method is baaed on 2-D theoretical analysis with modification for considering the actual 3-D nature of current flow. In order to determine the shape and size of the crack, measured distribution of the potential drop is compared with the 2-D analysis for a respective segment, which is based on the stream line, in the circumferential direction of the pipe. containing an assumed crack.
and Material
Engineering, Vol. 38, No. 2, pp. 273-280 (Apr. 1995) A method is developed for applying the d-c potential drop technique to
has been developed to enable reliable crack detection and sizing in a wide range of applications. Since its introduction in 1991 it has been adopted by a
simplified nondestructive evaluation of a circumferential 3-D crack on the
120
Acoustic emission response of 18% Ni maraging steel weldment’ with inserted cracks of varying depth to thickness ratio Materials Evaluation, Vol. 53, No. 6, pp. 742-746 (Jun. 1995) Acoustic emission studies have been carried out on a batch of welded and centre cracked specimens made of 18% Ni M250 maraging steel where the crack depth to specimen thickness ratio varied from approximately IO/80 to 25/80. The paper brings out the AE performance of the specimens with inserted surface cracks of different sizes when the latter become critically severe leading to failure. The studies indicate the predictions possibility for the hardware constructed out of this material reasonably well before their final rupture. The AE signatures are also presented in a form that would facilitate generation of an acceptance criteria for the evaluation of hardware in real time. 58498
Fang, C.K.; Kannatey-Asibu, E.; Barber, J.R.
Acoustic emission investigation of cold cracking in gas metal arc welding of AISI 4340 steel Welding Research, Vol. 74, No. 6, pp. 177s- 184s (Jun. 1995) Acoustic emission (AE) has been used to investigate the propagation of a finite crack in a weldment subjected to nonuniform longitudinal residual stresses during gas metal arc welding (GMAW). Cold cracking in selected weldments was accelerated using the electrochemical method to cathodically charge the weldments with hydrogen in order to induce hydrogen embrittlement. The envelopes for both spectra were found to decrease with increasing frequency, while the fluctuations in each curve diminished at high Frequencies.
57808
Skubis, J.; Jezierski, G.; Ranachowski, J.
Wade Edens, C.
Hill, E.v.K.; Knotts, G.L.
The acoustic emission (AE) flaw growth activity was monitored in aluminum-lithium weld specimens subjected to tensile loading. From an initial set of three specimens it was found that the tensile load associated with the peak of the AE events versus load curve could be.correlated directly with the ultimate load that the specimen would carry. This correlations was found to exist at loads less than or equal to 50% of the specimen’s ultimate load. Thus, an ultimate load prediction equation was generated. This technique was then applied to predict ultimate strengths in a second set of twelve specimens.
of 13 HMF steel and the results of simultaneous measurements of the acoustic emission generated during tension. The second part of the article discusses fhe results of measurements of the acoustic emission generated in the welds during heat treatment. The authors present a detailed discussion of heat treatment processes, the measurement system used in process conditions, and numerical methods for recording and analyzing the results.
57273
Saks, M.; Hara, K.; Abe, H.
Topp; Hughes; Michaels; Laenen
The use of ACFM during space flight and its application to more general weld inspection 6th European Conference on Non Destructive Testing, Nice (France), 24- 28 Oct. 1994. Vol. 1. pp. 5 13-5 18. ECNDT (1994) The alternatingcurrent field measurement (ACFM) inspection technique
Simplified NDE of a crack in a pipe weld by means of the potential drop technique Series A - Mechanics
This paper describes a multi-element, eddy current array for the local testing of ferritic specimens including welds. A novel transient method is used to extract coil impedance parameters, and has the advantage of fast measurement, digital compatibility and a minimum of front-end components; a useful feature when large element numbers are involved. The problem of displaying lift-off and flaw information from an array is solved by using a novel ‘volcano display’, which provides a simple two-dimensional image of conditions under the array.
Predicting ultimate strengths of aluminum-lithium (AI-Li) welds using acoustic emission ASNT 1993 Spring Conference and 2nd Annual Research Symposium, Nashville, Tennessee (United States), 29 Mar. -2 Apr. 1993. pp. 81-83. ASNT (1993) ISBN o-931403-13-8
Measurements of the material characteristics and the acoustic emission of a 13 HMF steel weld (In Polish) Polish Academy of Sciences, Warsaw (Poland) N95-10246/3/GAR, 114pp. (1992) This article describes the current status of research on an acoustic emission method for detecting material defects in welds of steel pipes made of 13 HMFsteel. The authors present the tension characteristics of samples
Journal
58261 McNab, A.; Thomson, J. An eddy current array instrument for application on ferritic welds NDT & E International, Vol. 28, No. 2, pp. 103-l 12 (1995)
Not since Bram Stoker’s “Dracula” has there been such interest generated in pressure vessel integrity. Coiled tubing is coming on strong as an alternative to jointed tubulars (tubing and drill pipe) used in the conventional workover unit. Several companies have either produced new wells or performed re-entry successfully into existing wells using coiled tubing. Manufacturers of coiled product are extending research into and some cases are now promoting coiled tubing “drilling pipe” performing at pressures exceeding 10,000 PSI with yield strength of 100,000 PSI. These increased performance levels now demanded of coiled tubing will require a closer nondestructive evaluation of the skelp.
Journal of Acoustic Emission, Vol. 12, No. 3-4, pp. 111-l 15 (Jul.-Dec. 1994) Acoustic emission studies have been carried out on a batch of center cracked M250 maraging steel welded specimens, having crack depth to specimen thickness ratio of 0.15 to 0.17. Broad-band AE sensors with 100-360 kHz bandpass filter have been employed for the experiments. The studies promise the prediction possibility for the hardware constructed out this material well before their final rupture and hence can facilitate generation of suitable acceptance criteria for the evaluation of hardware in real time.
JSME International
(Feb. 1992) The prototype of a testing devise for the nondestructive detection and identification of defect location and dimensions in a piping, especially of cracks in welded joints, has been evaluated on a laboratory scale. For a variety of reasons, it was not possible yet to perform trials in an industrial-scale system, as eg. in a power plant pipe system or the like.
Coiled tubing: early warning system to detect flaws in flat sheet prior to rolling and welding 1993 International Chemical and Petroleum Industry Inspection Technology III, Topical Conference, Houston, Texas (United States), 14- 16 Jun. 1993, pp. 20-24. ASNT (1993) ISBN O-931403-15-4
Acoustic emission response of centre cracked M250 maraging steel welded specimens
58468
58333 Wuensch, W. Design and testing of equipment for nondestructive detection and identification of the location and dimensions of materials defects, especially of cracks in welded joints of pipe systems (In German, English abstract) und Naturschutz fuer Umwelt, Bundesministerium Reaktorsicherheit, Bonn (Germany), TIB/B94_02356/GAR, 196pp.
57843
58493 Chelladurai, T.; Sankaranarayanan, AS.; Purushothaman, K.K.
58490
inner surface of a welded pipe. The pipe is welded circumferentially and the crack exists vertically to the inner surface at the weld. Potential drop is measured on the outer surface of the pipe. The method is baaed on 2-D theoretical analysis with modification for considering the actual 3-D nature of current flow. In order to determine the shape and size of the crack, measured distribution of the potential drop is compared with the 2-D analysis for a respective segment, which is based on the stream line, in the circumferential direction of the pipe. containing an assumed crack.
and Material
Engineering, Vol. 38, No. 2, pp. 273-280 (Apr. 1995) A method is developed for applying the d-c potential drop technique to
has been developed to enable reliable crack detection and sizing in a wide range of applications. Since its introduction in 1991 it has been adopted by a
simplified nondestructive evaluation of a circumferential 3-D crack on the
120