Abstract
Flow Accelerated Corrosion (FAC) of carbon steel is a phenomenon that has been studied for many years. However, to date, the specific behavior of welds and weld assemblies of carbon steel towards this phenomenon has been scarcely examined. An experimental program of FAC of welds and weld assemblies is being conducted by EDF and CRIEPI. This paper describes the results obtained on the behavior of weld metal independently of its behavior in a weld assembly as well as the sensitivity to FAC of various weld assembly configurations. Tests are performed, at EDF, in the CIROCO loop which permits to follow the FAC rate by gammametry measurements, and at CRIEPI, in the PRINTEMPS loop where FAC is measured by laser displacement sensor. Welds are performed by two different methods: Submerged Arc Welding (SAW) and Gas Tungsten Arc Welding (GTAW). The influence of several parameters on FAC of welds is examined: welding method, chromium content and temperature. For weld assemblies, only the impact of chromium content is studied. All the tests are conducted in ammonia medium at pH 9.0 and oxygen concentration lower then 1 ppb. Chemical parameters, as the pH, the conductivity and oxygen concentration, are measured in situ during the test and surface characterizations are performed after the test. The results show that, with more than 0.15% chromium, no FAC is detected on the weld metal, which is similar to the base metal behaviour. For the same and lower chromium content, the two types of metal have the same FAC rate. Concerning the temperature effect, for both metals FAC rate decreases with temperature increase above 150°C. Below 150 °C, their behaviour seems to be different. For weld assemblies, the study of different configurations shows that the chromium content is the main parameter affecting the behaviour of the specimens. Additional tests and modeling studies will be conducted in order to complete the results.
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References
B. Chexal & al., “Flow-Accelerated Corrosion in Power Plants”, EPRI, EDF, Siemens AG Power Generation Report TR-106611-R1, July 1998.
M. Persoz & al., “Analysis of thickness measurements on secondary lines in EDF PWRs to evaluate the accuracy of the flow accelerated corrosion monitoring software: BRT-CICERO”, Proceedings of the International Symposium on the Contribution of Materials Investigations to Improve the Safety and Performance of LWRs, Fontevraud, France, 18–22 September 2006.
M. Bouchacourt & al., “The impact of water chemistry on corrosion-erosion in one-phases and two-phase flow”, Proceedings of the 5 th International Conference on Water Chemistry of Nuclear Reactor Systems, Bournemouth, United Kingdom, 23–27 Octobre 1989.
J. Ducreux, “Theoretical and experimental investigation of the effect of chemical composition of steels on their erosion-corrosion resistance”, Proceedings of the International Specialists Meeting on Erosion-Corrosion of Steels in High Temperature Water and Wet Steam, Les Renardières, France, 1982.
I. S. Woolsey & al., ““The influence of oxygen and hydrazine on the erosion-corrosion behaviour and electrochemical potentials of carbon steel under boiler feedwater conditions”, Proceedings of the 4 th Water chemistry for nuclear reactor systems, Vol.1, Paper 96, BNES, London, 1986.
O. de Bouvier & al, “About the effect of high hydrazine chemistry on FAC occurrence in PWR’s Steam Generators”, Proceedings of the International Conference of Water Chemistry of Nuclear Reactor Systems, Vol. 2, 506, Bournemouth, United Kingdom, pp. 22–26 October 2000.
[7] O. de Bouvier & al, “Redox Conditions Effect on Flow Accelerated Corrosion: Influence of Hydrazine and Oxygen”, Proceedings of the International Conference of Water Chemistry of Nuclear Reactor Systems, Avignon, France, 22–26 April (2002).
[8] E. M. Pavageau, “Of the Role of Temperature and pH on the Hydrazine Effect on Flow Accelerated Corrosion”, Proceedings of the International Conference on Water Chemistry, San Francisco, October 2004.
E.M Pavageau & al., “Update of the water chemistry effect on the flow-accelerated corrosion rate of carbon steel: influence of hydrazine, boric acid, ammonia, morpholine and ethanolamine”, Proceedings of the 13 th International Conference on Environmental Degradation Conference, Vancouver, Canada, August 2007.
P. Leterrible, “Etude de la corrosion-erosion de l’acier non allies dans les conditions des echangeurs de chaleur des centrales nucléaires par la technique d’activation au moyen de particules chargees”, THESE de l’Institut National Polytechnique de Toulouse, Soutenance le 5 octobre 1984.
M. Bouchacourt, EDF Internal Report, T.42, 1982.
F.H Sweeton and C.F Baes, Journal of Chemical Thermodynamics, vol.2, p. 479, 1970.
P.R Tremaine and J.C Leblanc, Journal of Solution Chemistry, vol. 9, p. 415, 1980.
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© 2011 TMS (The Minerals, Metals & Materials Society)
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Mansour, C. et al. (2011). Flow Accelerated Corrosion of Carbon Steel in the Feedwater System of PWR Plants - Behaviour of Welds and Weld Assemblies. In: Busby, J.T., Ilevbare, G., Andresen, P.L. (eds) Proceedings of the 15th International Conference on Environmental Degradation of Materials in Nuclear Power Systems — Water Reactors. Springer, Cham. https://doi.org/10.1007/978-3-319-48760-1_55
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DOI: https://doi.org/10.1007/978-3-319-48760-1_55
Publisher Name: Springer, Cham
Online ISBN: 978-3-319-48760-1
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