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Magnetic NDT methods for microstructural characterisation in steels
N DT Abstracts Siphahi,L.B.; Govindaraju, M.R.; Jiles, D.C.; Liaw, P.K.; Drinon, D.S.
induction emf and of the Barkhausen discontinuities for the nondestructive testing of the microstructure of patented steel wire with 0.5 to 0.9% carbon content of the steel. The article describes an automated computerized installation and a method of evaluating the microstructure according to Sour parameters with three frequencies for exciting the specimen by an alternating magnetic field. 57730
56794
Magnetic Barkhausen effect stud.les in the evaluation of neutron i r r a d i a t i o n degradation in n u c l e a r p r e s s u r e vessel steels Review of Progress in Quantitative Nondestructive Evaluation, Brunswick, Maine (United States), 1-6 Aug. 1993. Vol. 13B, pp. 1801- 1808. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1994) ISBN 0-306-4473 i-2 It is shown that the use of magnetic Barkhansen noise measurements can reveal neutron irradiation degradation in nuclear power plant components. The measurements were conducted on base and weld parts of Charpy specimens of ASTM A533 Grade B class I pressure vessel steels using a commercial Barkhausen effect device. The data include magnetic Barkhansen signal parameter and Barkhausen voltage signals. The results of different neutron fluences and annealing procedures are discussed showing their effects on radiation hardening and changes in the Barkhausen signal parameter.
BhattachaJya, D.K.; Jayakumar, T.; Raj, B.
Magnetic NDT methods for microstructural characterisation in steels Non-Destructive Evaluation and Quality Assurance. Edited by C.R.L. Murthy, B. Raj, O. Prabhakar and A. Sreenivasulu. pp. 110-127. Interline Publishing (1993) ISBN 81-7296-010-7 This paper presents the results on investigations on the use of magnetic techniques for the characterisation of microstructures in steel specimens. The magnetic techniques include the use of Magnetic and Acoustic Barkhausen noise (MBN and ABN) analysis, and B-H hysteresis loop parameters. The analyses were carried out in heat treated I7-4-PH stainless steel, 2.25Cr-IMo ferritic steel, and A533B steel, and cold worked 304 stainless steel. The paper explains the instrumentations needed, test parameters used and the correlation of the parameters with the microstructural features. The results show that the techniques can be used in practical situations. 57728
56717
Le Brun, A.; Billy, F.
Nondestructive fatigue damage assessment using ultrasonic and magnetic measurements on metallic materials Review of Progress in Quantitative Nondestructive Evaluation, Brunswick, Maine (United States), 1-6 Aug. 1993. Vol. 13B, pp. 1833- 1840. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1994) ISBN 0-306-44731-2 In a nuclear power plant, degradation of materials is basically due to mechanical fatigue damage, thermal aging, radiation embrittlement, and corrosion. This article exposes the results obtained using two types of techniques, magnetic and acoustic, with a view to assessing damage by mechanical fatigue. We sought to establish a correlation between the assessment of a measured parameter and the progressive damage conditions of the material. The magnetic method is based on the Barkhausen emission. The acoustic method involves following the development of the Rayleigh wave propagation velocity. The feasibility tests presented were conducted on a mild steel used to produce secondary circuit piping, and on an alloy used to build turbines. During the first stress cycles, it is noted that the measurements are especially sensitive to relaxing of residual stress.
Mitra, A.; Chen, Z3.; Jiles, D.C.
Nondestructive magnetic measurements in weld and base metals of service exposed Cr-Mo steel NDT & E International, Vol. 28, No. 1, pp. 29-33 (Feb. 1995) Magnetic hysteresis and micromagnetic Barkhausen parameters were measured in base and weld metals of a service exposed Cr-Mo steel. Although the coercivity was higher in the welds, the difference in hysteresis parameters between welds and base metals was small. Hence, hysteresis parameters were not suitable to distinguish service exposed weld and base metals. Howevcr, a significant variation in Barkhausen waveforms was observed between base and weld metals. The difference in Barkhansen activity was most prominent at low magnetizing fields. The results of this study have been correlated with the microstructure of the samples.
Krause, T.W.; Atherton, D.L.
Ginsztler, J.; Meszaros, I.; Devenyi, L.; Hidasi, B.; Potgieter, J.H.
56519
Magnetic investigations of stainless steels
NDT&E International, Vol. 27, No. 4, pp. 201-207 (Aug. 1994) High resolution magnetic Barkhausen noise (MBN) measurements of slits in steel have been made using a small magnetic disk head mounted in a U-shaped laminated sweep field core. Detection occurred for sweep fields oriented both parallel and perpendicular to a slit or through- cut. For sweep fields oriented parallel to slits with widths from 0.25 mm to 0.7 mm, a maximum depression of 62% to 95% of the MBN signal was found. The range of depression was a factor of 2 to 5 times larger for sweep fields applied perpendicular to the slit. Results are interpreted in terms of the ability of the small magnetic disk read head to resolve small regions of non-uniform magnetization that produced MBN.
57497
High resolution magnetic Barkhausen noise measurements
International Journal of Pressure Vessels and Piping, Vol. 61, No. 2-3, pp. 471-478 (1995) A well known method to measure the ferrite content of stainless steels, is by potentiostatic etching. However, since the ferrite phase is the only ferromagnetic phase in the investigated stainless steels, Barkhausen noise measurement is a potentially su~itablemethod to accomplish the same goal. In order to evaluate this, a set of measurements was performed on two types of experimental stainless steels to compare the correlation between Barkhausen noise measurements, saturation induction measurements and a set of values obtained by potentiostatic etching. 57496
56106
Rai, S.; Rao, C.B.; Bhattacharya, D.K.; Raj, B.; Sethi,
V.K. Assessment of residual stresses and post weld heat treatment in b u t t weld j o i n t s of 2.25 C r . l M o steel tubes by x-ray diffraction technique and Barkausen noise analysis
Nondestructive Testing and Evaluation, Vol. 10, No. 5, pp. 287-294 (1993) Magnetic Barkhausen noise (MBN) measurements were made on a sample of pipeline steel to study the effect of magnetic flux density on the tensile stress dependence of MBN; The results suggest that MBN activity generally increases with flux density but begins to decrease slightly at higher flux densities. Similar behaviour is found at all tensile stress levels both when the stress is parallel and perpendicular to the applied field. The stress dependence of the MBN also sows a strong dependence on the flux density. However, at high flux density when the magnetic field is perpendicular to the stress, the MBN rms voltage saturates with increasing stress. These results are explained in terms of domain wall dynamics by considering the effect of the relative orientations of the magnetic flux density and applied tensile stress with respect to the easy axis of magnetization of the sample.
6th European Conference on Non Destructive Testing, Nice (France), 24- 28 Oct. 1994. Vol. 2, pp. 1239-1240. ECNDT (1994) Residual stresses in autogenous butt weld joints in 2.25 Cr -1 Mo steel tube were measured using X-ray Diffraction (XRD) and Barkhausen Noise Analysis (BNA). Post Weld Heat Treatment (PWHT) conditions were established for relieving of re:;idual stresses. Equality of BN activity in parent metal and Heat Affected Zone (HAZ) is found to be an indicator of adequate PWHT). 57261 Stress
Posgay, G.; Imre, L.
examination of bridges measurement
using Barkhausen
Dhar,A.; Atherton, D.L.
Effects of magnetic flux density and tensile stress on the magnetic Barkhausen noise in pipeline steel
noise
6th European Conference on Non Destructive Testing, Nice (France), 24- 28 Oct. 1994. Vol. 1. pp. 297-301. ECNDT (1994) Stress examination plays an important part in the construction of steel bridges which, nowadays, are generally made by welding, and in the investigation of existing structures. This paper presents the utilisation possibilities of a stress examination method using magnetic Barkhausen noise measurement for construction, test loading and subsequent checks of bridges; based on the experience we have gathered for the past 10 years.
56105
Gondi,P.; Mattogno, G.; Sili, A.; Foderaro, G.
Structural characteristics at surface and Barkhausen noise in AISI 4340 steel after grinding Nondestructive Testing and Evaluation, Vol. 10, No. 5, pp. 255-267 (1993) Structural effects of wet and dry grinding on AISI 4340 steel have been examined by X-ray diffraction analyses, metallographic observations and
335
induction emf and of the Barkhausen discontinuities for the nondestructive testing of the microstructure of patented steel wire with 0.5 to 0.9% carbon content of the steel. The article describes an automated computerized installation and a method of evaluating the microstructure according to Sour parameters with three frequencies for exciting the specimen by an alternating magnetic field. 57730
56794
Magnetic Barkhausen effect stud.les in the evaluation of neutron i r r a d i a t i o n degradation in n u c l e a r p r e s s u r e vessel steels Review of Progress in Quantitative Nondestructive Evaluation, Brunswick, Maine (United States), 1-6 Aug. 1993. Vol. 13B, pp. 1801- 1808. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1994) ISBN 0-306-4473 i-2 It is shown that the use of magnetic Barkhansen noise measurements can reveal neutron irradiation degradation in nuclear power plant components. The measurements were conducted on base and weld parts of Charpy specimens of ASTM A533 Grade B class I pressure vessel steels using a commercial Barkhausen effect device. The data include magnetic Barkhansen signal parameter and Barkhausen voltage signals. The results of different neutron fluences and annealing procedures are discussed showing their effects on radiation hardening and changes in the Barkhausen signal parameter.
BhattachaJya, D.K.; Jayakumar, T.; Raj, B.
Magnetic NDT methods for microstructural characterisation in steels Non-Destructive Evaluation and Quality Assurance. Edited by C.R.L. Murthy, B. Raj, O. Prabhakar and A. Sreenivasulu. pp. 110-127. Interline Publishing (1993) ISBN 81-7296-010-7 This paper presents the results on investigations on the use of magnetic techniques for the characterisation of microstructures in steel specimens. The magnetic techniques include the use of Magnetic and Acoustic Barkhausen noise (MBN and ABN) analysis, and B-H hysteresis loop parameters. The analyses were carried out in heat treated I7-4-PH stainless steel, 2.25Cr-IMo ferritic steel, and A533B steel, and cold worked 304 stainless steel. The paper explains the instrumentations needed, test parameters used and the correlation of the parameters with the microstructural features. The results show that the techniques can be used in practical situations. 57728
56717
Le Brun, A.; Billy, F.
Nondestructive fatigue damage assessment using ultrasonic and magnetic measurements on metallic materials Review of Progress in Quantitative Nondestructive Evaluation, Brunswick, Maine (United States), 1-6 Aug. 1993. Vol. 13B, pp. 1833- 1840. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1994) ISBN 0-306-44731-2 In a nuclear power plant, degradation of materials is basically due to mechanical fatigue damage, thermal aging, radiation embrittlement, and corrosion. This article exposes the results obtained using two types of techniques, magnetic and acoustic, with a view to assessing damage by mechanical fatigue. We sought to establish a correlation between the assessment of a measured parameter and the progressive damage conditions of the material. The magnetic method is based on the Barkhausen emission. The acoustic method involves following the development of the Rayleigh wave propagation velocity. The feasibility tests presented were conducted on a mild steel used to produce secondary circuit piping, and on an alloy used to build turbines. During the first stress cycles, it is noted that the measurements are especially sensitive to relaxing of residual stress.
Mitra, A.; Chen, Z3.; Jiles, D.C.
Nondestructive magnetic measurements in weld and base metals of service exposed Cr-Mo steel NDT & E International, Vol. 28, No. 1, pp. 29-33 (Feb. 1995) Magnetic hysteresis and micromagnetic Barkhausen parameters were measured in base and weld metals of a service exposed Cr-Mo steel. Although the coercivity was higher in the welds, the difference in hysteresis parameters between welds and base metals was small. Hence, hysteresis parameters were not suitable to distinguish service exposed weld and base metals. Howevcr, a significant variation in Barkhausen waveforms was observed between base and weld metals. The difference in Barkhansen activity was most prominent at low magnetizing fields. The results of this study have been correlated with the microstructure of the samples.
Krause, T.W.; Atherton, D.L.
Ginsztler, J.; Meszaros, I.; Devenyi, L.; Hidasi, B.; Potgieter, J.H.
56519
Magnetic investigations of stainless steels
NDT&E International, Vol. 27, No. 4, pp. 201-207 (Aug. 1994) High resolution magnetic Barkhausen noise (MBN) measurements of slits in steel have been made using a small magnetic disk head mounted in a U-shaped laminated sweep field core. Detection occurred for sweep fields oriented both parallel and perpendicular to a slit or through- cut. For sweep fields oriented parallel to slits with widths from 0.25 mm to 0.7 mm, a maximum depression of 62% to 95% of the MBN signal was found. The range of depression was a factor of 2 to 5 times larger for sweep fields applied perpendicular to the slit. Results are interpreted in terms of the ability of the small magnetic disk read head to resolve small regions of non-uniform magnetization that produced MBN.
57497
High resolution magnetic Barkhausen noise measurements
International Journal of Pressure Vessels and Piping, Vol. 61, No. 2-3, pp. 471-478 (1995) A well known method to measure the ferrite content of stainless steels, is by potentiostatic etching. However, since the ferrite phase is the only ferromagnetic phase in the investigated stainless steels, Barkhausen noise measurement is a potentially su~itablemethod to accomplish the same goal. In order to evaluate this, a set of measurements was performed on two types of experimental stainless steels to compare the correlation between Barkhausen noise measurements, saturation induction measurements and a set of values obtained by potentiostatic etching. 57496
56106
Rai, S.; Rao, C.B.; Bhattacharya, D.K.; Raj, B.; Sethi,
V.K. Assessment of residual stresses and post weld heat treatment in b u t t weld j o i n t s of 2.25 C r . l M o steel tubes by x-ray diffraction technique and Barkausen noise analysis
Nondestructive Testing and Evaluation, Vol. 10, No. 5, pp. 287-294 (1993) Magnetic Barkhausen noise (MBN) measurements were made on a sample of pipeline steel to study the effect of magnetic flux density on the tensile stress dependence of MBN; The results suggest that MBN activity generally increases with flux density but begins to decrease slightly at higher flux densities. Similar behaviour is found at all tensile stress levels both when the stress is parallel and perpendicular to the applied field. The stress dependence of the MBN also sows a strong dependence on the flux density. However, at high flux density when the magnetic field is perpendicular to the stress, the MBN rms voltage saturates with increasing stress. These results are explained in terms of domain wall dynamics by considering the effect of the relative orientations of the magnetic flux density and applied tensile stress with respect to the easy axis of magnetization of the sample.
6th European Conference on Non Destructive Testing, Nice (France), 24- 28 Oct. 1994. Vol. 2, pp. 1239-1240. ECNDT (1994) Residual stresses in autogenous butt weld joints in 2.25 Cr -1 Mo steel tube were measured using X-ray Diffraction (XRD) and Barkhausen Noise Analysis (BNA). Post Weld Heat Treatment (PWHT) conditions were established for relieving of re:;idual stresses. Equality of BN activity in parent metal and Heat Affected Zone (HAZ) is found to be an indicator of adequate PWHT). 57261 Stress
Posgay, G.; Imre, L.
examination of bridges measurement
using Barkhausen
Dhar,A.; Atherton, D.L.
Effects of magnetic flux density and tensile stress on the magnetic Barkhausen noise in pipeline steel
noise
6th European Conference on Non Destructive Testing, Nice (France), 24- 28 Oct. 1994. Vol. 1. pp. 297-301. ECNDT (1994) Stress examination plays an important part in the construction of steel bridges which, nowadays, are generally made by welding, and in the investigation of existing structures. This paper presents the utilisation possibilities of a stress examination method using magnetic Barkhausen noise measurement for construction, test loading and subsequent checks of bridges; based on the experience we have gathered for the past 10 years.
56105
Gondi,P.; Mattogno, G.; Sili, A.; Foderaro, G.
Structural characteristics at surface and Barkhausen noise in AISI 4340 steel after grinding Nondestructive Testing and Evaluation, Vol. 10, No. 5, pp. 255-267 (1993) Structural effects of wet and dry grinding on AISI 4340 steel have been examined by X-ray diffraction analyses, metallographic observations and
335