Localised corrosion of iron and steel in the Callovo-Oxfordian porewater after 3 months at 120 °C: Characterizations at micro and nanoscale and formation mechanisms

Hélène Lotz (1) , Delphine Neff (1, 2, 3) , Florence Mercier-Bion (1, 2, 3) , Christian Bataillon (4) , Philippe Dillmann (1, 2, 3) , Emmanuel Gardés (5) , Isabelle Monnet (5, 6) , James Dynes (7, 8) , Eddy Foy (1, 2, 3)

1 IRAMAT-LAPA - IRAMAT - Laboratoire Archéomatériaux et Prévision de l'Altération
2 NIMBE UMR 3685 - Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M)
3 LAPA - UMR 3685 - Laboratoire Archéomatériaux et Prévision de l'Altération
4 SCCME - Service de la Corrosion et du Comportement des Matériaux dans leur Environnement
5 CIMAP - UMR 6252 - Centre de recherche sur les Ions, les MAtériaux et la Photonique
6 MADIR - Matériaux, Défauts et IRradiations
7 Canadian Light Source Inc.
8 U of S - University of Saskatchewan [Saskatoon, Canada]

To investigate the fate of nuclear waste in geologic repositories, corrosion experiments were performed on a ferrito‐pearlitic (P285‐NH) and a ferritic steel (Armco) in a synthetic solution representing the Callovo-Oxfordian porewater for 3-months at 120°C. Corrosion product layers (CPL) were characterized from micro to nanoscale. Local corrosion areas of higher thicknesses were composed of siderite layers with different nano-morphologies, iron silicate, iron sulphate and magnetite. Their formation could be due to local pH variation, but also on metal microstructure (phases location and morphology). Differences in corrosion progress are suggested to be mainly related to differences in porewater chemistry and cathodic sites

Keywords: Steel; SEM; Raman; STXM/XANES; MET/SAED; localized corrosion; nuclear waste repository

Domains: Chemical Sciences

Hélène Lotz, Delphine Neff, Florence Mercier-Bion, Christian Bataillon, Philippe Dillmann, et al.. Localised corrosion of iron and steel in the Callovo-Oxfordian porewater after 3 months at 120 °C: Characterizations at micro and nanoscale and formation mechanisms. Corrosion Science, 2023, 219, pp.111235. ⟨10.1016/j.corsci.2023.111235⟩. ⟨cea-04095917⟩