Calibration of the local IGSCC engineering model for Alloy 600

Thierry Couvant (1) , Jacqueline Caballero (1) , Cecilie Duhamel (2) , Jérôme Crépin (2) , Takaharu Maeguchi

1 EDF - EDF
2 MAT - Centre des Matériaux

Many Stress Corrosion Cracking (SCC) models have been developed so far. Quantitative empirical models, trying to predict initiation and crack growth rate of nickel alloys exposed to pressurized water reactor primary water do not describe physical mechanism and suffer a lack of accuracy. By contrast, models describing the possible involved physical mechanisms responsible for degradation (selective oxidation of grain boundaries in the case of Alloy 600 exposed to PWR primary water) are usually qualitative. In the current paper, a ‘local’ model is proposed to better predict SCC. In order to succeed, behaviors assumed to be involved in the SCC process were calibrated and coupled: intergranular oxidation rate, intergranular stresses, resistance to cracking of oxidized grain boundaries. The output of the model is the time to reach a given crack depth. This paper introduces the first calibration of parameters for Alloy 600 exposed to primary water.

Mots clés: Intergranular stress corrosion cracking; Intergranular oxidation; Primary water; Alloy 600; Crystal plasticity; Fracture of oxidized grain boundaries; Local model; Initiation; Crack growth

Domaines: Physique [physics]; Matière Condensée [cond-mat]; Science des matériaux [cond-mat.mtrl-sci]

Thierry Couvant, Jacqueline Caballero, Cecilie Duhamel, Jérôme Crépin, Takaharu Maeguchi. Calibration of the local IGSCC engineering model for Alloy 600. EDM 2017: Proceedings of the 18th International Conference on Environmental Degradation of Materials in Nuclear Power Systems – Water Reactors, Aug 2017, Portland, United States. pp.295-317. ⟨hal-01631874⟩