Investigation of steel corrosion in MX80 bentonite at 120°C

Hélène Lotz (1, 2) , Charly Carrière (1, 2) , Christian Bataillon (3) , Emmanuel Gardes (4) , Isabelle Monnet (4) , Eddy Foy (1, 2) , Michel L Schlegel (5) , James J Dynes (6, 7) , Delphine D. Neff (1, 2) , Florence F. Mercier-Bion (1, 2) , Philippe Dillmann (1, 2)

1 LAPA - UMR 3685 - Laboratoire Archéomatériaux et Prévision de l'Altération
2 IRAMAT - LMC - IRAMAT - Laboratoire Métallurgies et Cultures
3 SCCME - Service de la Corrosion et du Comportement des Matériaux dans leur Environnement
4 CIMAP - UMR 6252 - Centre de recherche sur les Ions, les MAtériaux et la Photonique
5 SEARS - Service d'études analytiques et de réactivité des surfaces
6 Canadian Light Source
7 U of S - University of Saskatchewan [Saskatoon]

Corrosion experiments were performed on two metallic substrates, a ferritic–pearlitic steel (P285NH) and a ferritic one (Armco), in silicate environment during 30 days at 120°C. Corrosion products were characterized in terms of morphology (scanning electron microscope and transmission electron microscopy), composition (energydispersive X-ray spectroscopy) and structure (µ-Raman, selected area electron diffraction, X-ray absorption near edge structure). Results show a nanometric inner layer made of compact and adherent nanocrystallized magnetite with, locally a thickness up to several micrometers due to the metal microstructure. An outer layer of Fe-rich phyllosilicate, smectite and serpentine, more porous than the inner one and poorly adherent is observed around both the samples.

Keywords: Steel; anoxic corrosion; MX80 bentonite; multiscale analysis; magnetite; iron silicate

Domains: Material chemistry

Hélène Lotz, Charly Carrière, Christian Bataillon, Emmanuel Gardes, Isabelle Monnet, et al.. Investigation of steel corrosion in MX80 bentonite at 120°C. Materials and Corrosion / Werkstoffe und Korrosion, 2021, 71 (1-2), pp.120-130. ⟨10.1002/maco.202011777⟩. ⟨cea-02931494⟩