Influence of ageing heat treatment on A-286 microstructure and stress corrosion cracking behaviour in PWR primary water - CEA - Commissariat à l’énergie atomique et aux énergies alternatives Accéder directement au contenu
Article Dans Une Revue Journal of Nuclear Materials Année : 2007

Influence of ageing heat treatment on A-286 microstructure and stress corrosion cracking behaviour in PWR primary water

Résumé

The influence of ageing heat treatment on alloy A-286 microstructure and stress corrosion cracking behaviour in simulated Pressurized Water Reactor (PWR) primary water has been investigated. A-286 microstructure was characterized by transmission electron microscopy for ageing heat treatments at 670 °C and 720 °C for durations ranging from 5 h to 100 h. Spherical $\gamma$′ phase with mean diameters ranging from 4.6 to 9.6 nm and densities ranging from 8.5 × 10$^{22}$ m$^{−3}$ to 2 × 10$^{23}$ m$^{−3}$ were measured. Results suggest that both the $\gamma$′ phase mean diameter and density quickly saturate with time for ageing heat treatment at 720 °C while the $\gamma$′ mean diameter increases significantly up to 100 h for ageing heat treatment at 670 °C. Grain boundary $\eta$ phase precipitates were systematically observed for ageing heat treatment at 720 °C even for short ageing periods. In contrast, no grain boundary η phase precipitates were observed for ageing heat treatments at 670 °C except after 100 h. Hardening by $\gamma$′ precipitation was well described by the dispersed barrier hardening model with a γ′ barrier strength of 0.23. Stress corrosion cracking behaviour of A-286 was investigated by means of constant elongation rate tensile tests at 1.5 × 10$^{−7}$ s$^{−1}$ in simulated PWR primary water at 320 °C and 360 °C. In all cases, initiation was transgranular while propagation was intergranular. Grain boundary $\eta$ phase precipitates were found to have no significant effect on stress corrosion cracking. In contrast, yield strength and to a lesser extent temperature were found to have significant influences on A-286 susceptibility to stress corrosion cracking.
Fichier principal
Vignette du fichier
200600000113.pdf (990.07 Ko) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

cea-02354106 , version 1 (20-11-2019)

Identifiants

Citer

M. Savoie, C. Esnouf, L. Fournier, D. Delafosse. Influence of ageing heat treatment on A-286 microstructure and stress corrosion cracking behaviour in PWR primary water. Journal of Nuclear Materials, 2007, 360 (3), pp.222-230. ⟨10.1016/j.jnucmat.2006.10.003⟩. ⟨cea-02354106⟩
52 Consultations
252 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More