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NDT of welds: state of the art
NDT&E International, Vol. 31, No. 1, pp. 65-74, 1998 Elsevier Science Ltd Printed in Great Britain ELSEVIER
PII: S0963-8695(97)00047-9
- N D T abstracts NDT Abstracts are compiled by AEA Technology National NDT Centre, Harwell, Oxon, OX11 0RA, UK. The entries a r e d r a w n f r o m o v e r 500 B r i t i s h a n d I n t e r n a t i o n a l p u b l i c a t i o n s . E a c h i s s u e c o n c e n t r a t e s o n o n e o r t w o s u b j e c t a r e a s .
Use of the Potential Drop m e t h o d in NDT 63926 Electric Power Research Institute Electrochemical noise monitoring of BWR systems Electric Power Research Institute, Palo Alto, CA (United States), TR- 107310, 110 pp. (Dec. 1996) Researchers conducted slow strain rate tensile (SSRT) tests on sensitized Type 304 stainless steels in simulated BWR water at 288sup(o)C/10.4 MPa. This enabled them to optimize the configuration of the electrochemical cell and analyze the electrochemical potential and current responses to cracking events. They also tested blunt notched compact tension (CT) specimens which were instrumented for measurement of crack initiation (using electrochemical current and potential noise monitoring) and crack growth (using de potential drop).
Keller, H.P.; Opperman, W. Method of early defect detection as reduced radiation exposure 62221
for periodic inspection a n d testing of safety-relevant pipework. P a r t : potential d r o p method (In G e r m a n ) Potentialsonden-Messtechnik, BMU--1996-455, 104 pp. (1996) A newly developed potential drop method was examined for application at periodic inspections in nuclear installations. The method can be applied to evaluate the size of flaws and inspect/monitor power plant components with wall thickness of up to 50 mm. If permanently installed, the set up is suitable for continuous monitoring of indications found by NDT and locations particularly at risk. It can be used to replace ultrasonic and radiographic inspections. It is possible now to make inspections during operation at 350 C, for instance as a long-term surveillance.
63728 Takahashi, K.; Shoji, T.; Nakajima, M. Effect of surface defects on fatigue properties of powder forged ferrous materials (In Japanese)
Ditchburn, RJ.; Burke, S.K.; Scala, C.M. NDT of welds: state of the a r t 61621
NDT & E International, Vol. 29, No. 2, pp. 11 I-I 17. (Apr, 1996) Major advances have been made in recent years in nondestructive testing of welded steel structures. This paper reviews the latest developments in: (i) radiographic inspection; (ii) ultrasonics; (iii) alternating current potential drop technique; (iv) measurement of residual stress, and (v) in-production weld inspection. Areas where further useful progress can be made are also identified.
Journal of the Japan Institute of Metals, Vol. 60, No. 9, pp. 816-825 (20 Sep. 1996) In order to understand the behavior of NSA in dynamic conditions, fractography and measurement of the NSA distribution on the fatigue origin were investigated. The behavior of crack initiation and propagation was observed during fatigue tests by using ACPD (the alternative current potential drop method) measurement and the tbermnelastic stress analysis system. The effects of NSA on fatigue properties were discussed on the basis of fracture mechanics.
61576 Deutsch, V.; Ettel, P.; Platte, M.; Cost, H. C r a c k d e p t h determination. A m o d e r n technique of a n established method (In G e r m a n : English abstract) Materialprufung, Vol. 38, No. 7-8, pp. 306-310 (Jul.-Aug. 1996) Measuring crack depths by the potential drop method is a well known NDT method, which is often applied in addition to magnetic particle or penetrant inspection of workpieces. It also monitors crack growth of mechanically loaded or chemically affected work-pieces. The accuracy and handling has been improved by a new pocket size digital crack depth gage and newly designed probes with integrated electronics for signal preprocessing and memory. Crack depth calculations are carried out with respect to prestored data of various materials of different electrical and magnetic properties.
Shek, G.K.; Jovanovic, M.T.; Seahra, H.; Ma, Y.; Li, D.; Eadie, R.L. Hydride morphology and striation formation during delayed hydride cracking in Z r - 2 . 5 % Nb 63357
Journal of Nuclear Materiais, Vol. 231, No. 3, pp. 221-230 (Aug. 1996) These experiments were designed to study hydride formation at the crack tip, acoustic emission (AE), potential drop (PD) and striation formation during DHC (delayed hydride cracking) in Zr-2.5% Nb. In simultaneous monitoring with acoustic emission and potential drop, both AE and PD jumps were shown to be monolithic.
61574 Jones, KJ.; Frise, P.R. T e m p e r a t u r e effects on DC potential drop measurements made on a zirconium alloy plate specimen Insight, Vol. 38, No. 5, pp. 341-345 (May 1996) A program to develop a DCPD crack measurement system for use on irradiated zirconium-niobium alloy nuclear reactor pressure-tuhe samples at high temperatures has required a series of tests to investigate the effect of high temperatures on the measurement system and data. The equipment and the test program are described, along with the results obtained. The tests have demonstrated that the DC system can function at the required temperatures (up to 250sup(o)C) but that some additional data reduction is required to remove or decrease the effect of the specimen temperature on the
Takahashi, K.; Shoji, T.; Nakajima, M. Effect of surface defects on fatigue properties of powder forged 62646
ferrous materials Journal of the Japan Institute of Metals, Vol. 60, No. 9, pp, 816-825 (1996) In order to understand the behavior of non-sintered areas (NSA) in dynamic conditions, fractography and measurement of the NSA distribution on the fatigue origin were investigated. The behavior of crack initiation and propagation was observed during fatigue tests by using ACPD (the alternative current potential drop method) measurement and the thermoelastic stress analysis system. The effects of NSA on fatigue properties were discussed on the basis of fracture mechanics.
measurements.
62222 Keller, H.P.; Oppermann, W. M e t h o d s for early defect detection a n d reduction of radiation
61331 Saka, M.; Oouchi, A.; Abe, H. NDE of a crack by using closely coupled probes for DCPD
exposure in periodic inspection and testing of safety-relevant pipework. Continuation of the tests with the potential drop method (In G e r m a n )
technique Journal of Pressure Vessel Technology - Transactions of the ASME, Vol. 118, No. 2, pp. 198-202 (1996) In order to enhance the sensitivity of the d-c potential drop technique, the principle of a technique using the closely coupled probes is proposed. A calibration equation of this technique is derived, where the path-independent integral j(e) for electric crack problem is utilized. Experiments on laboratory specimens are discussed which validate the use of the calibration equation for the nondestructive evaluation of cracks. It is shown that the sensitivity of the present method using closely coupled probes is higher than that of the usual method using a uniform current flow in the region far from the crack.
Fortfuehrung der Untersuchungen zur PotentialsondenMesstechnik, B M U - - 1996-456, 70 pp. (1996) The potential drop method was examined for application in periodic inspections in nuclear facilities. Five installations in nuclear power plants each tested for over about 1 year --confirm that the set up is suitable -if permanently installed -for continuous monitoring of indications found by NDT and locations particularly at risk. it can be used to replace ultrasonic and radiographic inspections.
65
PII: S0963-8695(97)00047-9
- N D T abstracts NDT Abstracts are compiled by AEA Technology National NDT Centre, Harwell, Oxon, OX11 0RA, UK. The entries a r e d r a w n f r o m o v e r 500 B r i t i s h a n d I n t e r n a t i o n a l p u b l i c a t i o n s . E a c h i s s u e c o n c e n t r a t e s o n o n e o r t w o s u b j e c t a r e a s .
Use of the Potential Drop m e t h o d in NDT 63926 Electric Power Research Institute Electrochemical noise monitoring of BWR systems Electric Power Research Institute, Palo Alto, CA (United States), TR- 107310, 110 pp. (Dec. 1996) Researchers conducted slow strain rate tensile (SSRT) tests on sensitized Type 304 stainless steels in simulated BWR water at 288sup(o)C/10.4 MPa. This enabled them to optimize the configuration of the electrochemical cell and analyze the electrochemical potential and current responses to cracking events. They also tested blunt notched compact tension (CT) specimens which were instrumented for measurement of crack initiation (using electrochemical current and potential noise monitoring) and crack growth (using de potential drop).
Keller, H.P.; Opperman, W. Method of early defect detection as reduced radiation exposure 62221
for periodic inspection a n d testing of safety-relevant pipework. P a r t : potential d r o p method (In G e r m a n ) Potentialsonden-Messtechnik, BMU--1996-455, 104 pp. (1996) A newly developed potential drop method was examined for application at periodic inspections in nuclear installations. The method can be applied to evaluate the size of flaws and inspect/monitor power plant components with wall thickness of up to 50 mm. If permanently installed, the set up is suitable for continuous monitoring of indications found by NDT and locations particularly at risk. It can be used to replace ultrasonic and radiographic inspections. It is possible now to make inspections during operation at 350 C, for instance as a long-term surveillance.
63728 Takahashi, K.; Shoji, T.; Nakajima, M. Effect of surface defects on fatigue properties of powder forged ferrous materials (In Japanese)
Ditchburn, RJ.; Burke, S.K.; Scala, C.M. NDT of welds: state of the a r t 61621
NDT & E International, Vol. 29, No. 2, pp. 11 I-I 17. (Apr, 1996) Major advances have been made in recent years in nondestructive testing of welded steel structures. This paper reviews the latest developments in: (i) radiographic inspection; (ii) ultrasonics; (iii) alternating current potential drop technique; (iv) measurement of residual stress, and (v) in-production weld inspection. Areas where further useful progress can be made are also identified.
Journal of the Japan Institute of Metals, Vol. 60, No. 9, pp. 816-825 (20 Sep. 1996) In order to understand the behavior of NSA in dynamic conditions, fractography and measurement of the NSA distribution on the fatigue origin were investigated. The behavior of crack initiation and propagation was observed during fatigue tests by using ACPD (the alternative current potential drop method) measurement and the tbermnelastic stress analysis system. The effects of NSA on fatigue properties were discussed on the basis of fracture mechanics.
61576 Deutsch, V.; Ettel, P.; Platte, M.; Cost, H. C r a c k d e p t h determination. A m o d e r n technique of a n established method (In G e r m a n : English abstract) Materialprufung, Vol. 38, No. 7-8, pp. 306-310 (Jul.-Aug. 1996) Measuring crack depths by the potential drop method is a well known NDT method, which is often applied in addition to magnetic particle or penetrant inspection of workpieces. It also monitors crack growth of mechanically loaded or chemically affected work-pieces. The accuracy and handling has been improved by a new pocket size digital crack depth gage and newly designed probes with integrated electronics for signal preprocessing and memory. Crack depth calculations are carried out with respect to prestored data of various materials of different electrical and magnetic properties.
Shek, G.K.; Jovanovic, M.T.; Seahra, H.; Ma, Y.; Li, D.; Eadie, R.L. Hydride morphology and striation formation during delayed hydride cracking in Z r - 2 . 5 % Nb 63357
Journal of Nuclear Materiais, Vol. 231, No. 3, pp. 221-230 (Aug. 1996) These experiments were designed to study hydride formation at the crack tip, acoustic emission (AE), potential drop (PD) and striation formation during DHC (delayed hydride cracking) in Zr-2.5% Nb. In simultaneous monitoring with acoustic emission and potential drop, both AE and PD jumps were shown to be monolithic.
61574 Jones, KJ.; Frise, P.R. T e m p e r a t u r e effects on DC potential drop measurements made on a zirconium alloy plate specimen Insight, Vol. 38, No. 5, pp. 341-345 (May 1996) A program to develop a DCPD crack measurement system for use on irradiated zirconium-niobium alloy nuclear reactor pressure-tuhe samples at high temperatures has required a series of tests to investigate the effect of high temperatures on the measurement system and data. The equipment and the test program are described, along with the results obtained. The tests have demonstrated that the DC system can function at the required temperatures (up to 250sup(o)C) but that some additional data reduction is required to remove or decrease the effect of the specimen temperature on the
Takahashi, K.; Shoji, T.; Nakajima, M. Effect of surface defects on fatigue properties of powder forged 62646
ferrous materials Journal of the Japan Institute of Metals, Vol. 60, No. 9, pp, 816-825 (1996) In order to understand the behavior of non-sintered areas (NSA) in dynamic conditions, fractography and measurement of the NSA distribution on the fatigue origin were investigated. The behavior of crack initiation and propagation was observed during fatigue tests by using ACPD (the alternative current potential drop method) measurement and the thermoelastic stress analysis system. The effects of NSA on fatigue properties were discussed on the basis of fracture mechanics.
measurements.
62222 Keller, H.P.; Oppermann, W. M e t h o d s for early defect detection a n d reduction of radiation
61331 Saka, M.; Oouchi, A.; Abe, H. NDE of a crack by using closely coupled probes for DCPD
exposure in periodic inspection and testing of safety-relevant pipework. Continuation of the tests with the potential drop method (In G e r m a n )
technique Journal of Pressure Vessel Technology - Transactions of the ASME, Vol. 118, No. 2, pp. 198-202 (1996) In order to enhance the sensitivity of the d-c potential drop technique, the principle of a technique using the closely coupled probes is proposed. A calibration equation of this technique is derived, where the path-independent integral j(e) for electric crack problem is utilized. Experiments on laboratory specimens are discussed which validate the use of the calibration equation for the nondestructive evaluation of cracks. It is shown that the sensitivity of the present method using closely coupled probes is higher than that of the usual method using a uniform current flow in the region far from the crack.
Fortfuehrung der Untersuchungen zur PotentialsondenMesstechnik, B M U - - 1996-456, 70 pp. (1996) The potential drop method was examined for application in periodic inspections in nuclear facilities. Five installations in nuclear power plants each tested for over about 1 year --confirm that the set up is suitable -if permanently installed -for continuous monitoring of indications found by NDT and locations particularly at risk. it can be used to replace ultrasonic and radiographic inspections.
65