Modelling of the effect of grain boundary diffusion on the oxidation of Ni-Cr alloys at high temperature

Léa Bataillou (1, 2) , Clara Desgranges (1, 3) , Laure Martinelli (1) , Daniel Monceau (2)

1 SCCME - Service de la Corrosion et du Comportement des Matériaux dans leur Environnement
2 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux
3 Safran Tech

Grain boundaries in oxide scales have a strong effect on oxidation kinetics when they act as diffusion short circuits. This study proposes a quantitative evaluation of the phenomenon by modelling. Various cases of oxide microstructure evolution are treated using both analytical and numerical resolutions. Results showed that the effect of oxide grain growth on the oxidation kinetics can be analysed considering a transitory stage for which the oxidation kinetics is not purely parabolic. Some guidelines for choosing the appropriate post-treatment method for the analysis and extrapolation of experimental oxidation kinetics are given.

Domains: Physics [physics]; Condensed Matter [cond-mat]; Materials Science [cond-mat.mtrl-sci]; Chemical Sciences; Material chemistry

Léa Bataillou, Clara Desgranges, Laure Martinelli, Daniel Monceau. Modelling of the effect of grain boundary diffusion on the oxidation of Ni-Cr alloys at high temperature. Corrosion Science, 2018, 136, pp.148-160. ⟨10.1016/j.corsci.2018.03.001⟩. ⟨cea-01818751⟩