Skip to Main content Skip to Navigation

Modélisation de l'amorçage de la Corrosion sous Contrainte en milieu primaire de l'alliage 600

Abstract : Several components present in the primary circuit of Pressurized Water Reactors (PWR) of nuclear power plants were manufactured with Alloy 600, a nickel base alloy containing 16 wt.% chromium. Operating experience of PWRs and laboratory tests showed that Alloy 600 is susceptible to stress corrosion cracking (SCC).Previous studies have allowed developing an initiation model based on a macroscopic approach and depending on several parameters such as temperature, applied stress and material microstructure. However, this model suffers from a lack of accuracy: dissolved hydrogen content and mechanical loading history effects are not considered and the microstructure effects (such as intergranular precipitation) are only partially taken into account.The aim of this study is to develop a ‘local’ model predicting stress corrosion cracking initiation time, based on physical mechanisms and local parameters related to the material microstructure (intergranular precipitation), the environment chemistry (temperature and dissolved hydrogen content) and stress concentration at grain boundaries. The local model relies on a cracking scenario with three main steps: incubation, initiation and crack extension.The formation of intergranular oxide penetration was assumed to be a key step in SCC initiation. For this purpose, oxidation tests were performed in simulated primary water. The intergranular oxidation kinetics of Alloy 600 was studied and the effects of intergranular carbide precipitation, dissolved hydrogen content and temperature were investigated. In addition, a cracking criterion coupling a critical local stress and a critical intergranular oxide depth was estimated. Finally, a sigmoid crack growth law was used to simulate both the slow and fast propagation steps. The local model was validated using a database built from the results of SCC tests performed on Alloy 600 and gathering the crack depths reached as a function of test duration for different experimental conditions (material microstructure, loading conditions).
Document type :
Complete list of metadata

Cited literature [112 references]  Display  Hide  Download
Contributor : ABES STAR :  Contact
Submitted on : Tuesday, November 14, 2017 - 10:11:26 PM
Last modification on : Wednesday, November 17, 2021 - 12:28:25 PM
Long-term archiving on: : Thursday, February 15, 2018 - 1:34:13 PM


Version validated by the jury (STAR)


  • HAL Id : tel-01635264, version 1


Jacqueline Caballero Hinostroza. Modélisation de l'amorçage de la Corrosion sous Contrainte en milieu primaire de l'alliage 600. Matériaux. Université Paris sciences et lettres, 2016. Français. ⟨NNT : 2016PSLEM034⟩. ⟨tel-01635264⟩



Record views


Files downloads