Stress corrosion cracking on cold-worked austenic stainless steels in PWR environment

• Autorzy: Tribouilloy L. , Vaillant F. , Olive J.-M. , Puiggali M.
• Języki publikacji: EN

Abstrakty

EN

Types 304L and 316L austenitic Stainless Steels (SS) are widely used in PWR environment. These past few years, a limited number of cases of intergranular stress corrosion cracking (IGSCC) have been detected in cold worked areas of non sensitized austenitic stainless steel components. A first study has been initiated at EDF to assess the conditions of the cracking. The main results include cold work thresholds of 240 HV 0,1 for initiation cracking, and of 310 HV 0,1 for crack propagation, and propose that a dynamic loading is necessary for SCC. The aim of the present paper is to provide a basis of a crack propaga-tion model by investigating the effcet of loading, material and cold-work. In order to try to approach a static loading, a trape-zoidal cyclic loading is applied on high cold-worked (by rolling or by tensile loading) materials. It is shown that, for the most severe loading, the rolling cold-worked (RCW) materials undergo TGSCC whereas IGSCC is observed after tensile cold-working (TCW). The ratio of loading R bas such a strong impact on the crack growth rate (CGR) that it modifies the mechanism of cracking. Moreover, we notice that CGR increases with the applied K max but this evolution depends on the R value. Therefore, [delta K] is chosen to represent the mechanical loading effects on CGRs. Finally, the CGR after a hold time of 1 hour is quite the same than for 3 hours. Additionally, to address the critical issue of the effecet of the crack tip strain rate on crack growth rate, Slow Strain Rate Tests (SSTR) are carried out on RCW specimens and provide a first relation which is not consistent to a pure anodic process. This study is going on TCW specimens.

Słowa kluczowe

EN

304L-316L; stainless steel; cold water; SCC; PWR

• Wydawca: Politechnika Gdańska
• Czasopismo: Advances in Materials Science
• Rocznik: 2007
• Tom: Vol. 7, nr 1(11)
• Strony: 61--69
• Opis fizyczny: Bibliogr. 9 poz., rys., tab.

Twórcy

autor

Tribouilloy L.

autor

Vaillant F.

autor

Olive J.-M.

autor

Puiggali M.

• EDF R&D, Moret sur Loing 77-818 France

Bibliografia

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• [5] T. Shoji, G. Li, J. Kwon, S. Matsushima, Z. Lu, Quantification ofyie1d strength effects on IGSCC in austenitic stainless steels in high temperature water, 2004, 11th Environmental Degradation of Materia1s in Nuclear Power Systems, Stevenson (W).
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• [7] C. Guerre, O. Raquet, E. Henns, M. Le Calvar, G. Turluer, SCC growth behaviour of austenitic stainless steels in PWR primary water conditions, in 12th Environmental Degradation of Materials in Nuclear Power Systems, 2005, Snowbird (UT).
• [8] P. Ford, Slip dissolution model, Bombannes 1990.
• [9] P. Ford, P.L. Andresen Parkins Symposium on Fundamental Aspects of Stress Corrosion Cracking: Proceeding of a Symposium Sponsored by TMS-ASM-MSD Corrosion and environmental effects committee, TMS, 1992.