Interaction between carbon steel and low-pH bentonitic cement grout in anoxic, high temperature (80°C) and spatially heterogeneous conditions

J. Goethals (1) , Laurent de Windt (2) , Charles Wittebroodt (3) , A. Abdelouas (1) , Xavier de La Bernardie (1) , Y. Morizet (4) , B. Zajec (5) , V. Detilleux (6)

1 SUBATECH - Laboratoire de physique subatomique et des technologies associées
2 GEOSCIENCES - Centre de Géosciences
3 IRSN/PSE-ENV/SEDRE/LETIS - Laboratoire d'étude et de recherche sur les transferts et les interactions dans les sous-sols
4 LPG - Laboratoire de Planétologie et Géosciences [UMR_C 6112]
5 ZAG - Slovenian National Building and Civil Engineering Institute = Zavod za gradbeništvo Slovenije
6 BEL V

Anoxic corrosion processes impacting carbon steel samples for both intimate and imperfect metal/ low-pH bentonitic cement grout (BCG) contacts were studied at 80 °C. SEM, XRD and µ-Raman spectroscopy analyses supported by geochemical modelling allowed a full characterization of the corrosion mechanism. Steel in direct contact with BCG suffered from localized corrosion (pits measuring up to 160 µm in depth after 150 days of exposure) principally triggered by the presence of HS-. Depending on silicate and sulphide ingress from the BCG towards the interface, neoformed magnetite may be converted to iron silicates and/or iron sulphides.

Mots clés: Anaerobic conditions; Galvanic coupling; Localized corrosion; Low-pH cement; Sulphides

Domaines: Matériaux

J. Goethals, Laurent de Windt, Charles Wittebroodt, A. Abdelouas, Xavier de La Bernardie, et al.. Interaction between carbon steel and low-pH bentonitic cement grout in anoxic, high temperature (80°C) and spatially heterogeneous conditions. Corrosion Science, 2023, 211, pp.110852. ⟨10.1016/j.corsci.2022.110852⟩. ⟨irsn-03880498⟩