Iron and steel corrosion mechanisms in a carbonate rich pore water: Multiscale characterization of the corrosion product layers

Hélène Lotz (1, 2) , Delphine Neff (1, 2) , Florence Mercier-Bion (1, 2) , Christian Bataillon (3) , Philippe Dillmann (1, 2) , Emmanuel Gardes (4) , Isabelle Monnet (4)

1 LAPA - UMR 3685 - Laboratoire Archéomatériaux et Prévision de l'Altération
2 IRAMAT-LAPA - IRAMAT - Laboratoire Archéomatériaux et Prévision de l'Altération
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

Corrosion experiments were performed on a ferrito-pearlitic (P285-NH) and a ferritic steel (Armco) in a synthetic solution representing the Callovo-Oxfordian porewater during a month at 120°C. Corrosion product layers (CPLs) were characterized from micro to nanoscale in terms of morphology (electron microscopies), composition (energy dispersive X-ray spectroscopy), and structure (µ-Raman, selected area electron diffraction). Both systems present a Ca-siderite bilayer which interface locates the metal original surface, and nano to micrometric magnetite islets on the internal carbonated layer and at the M/CPL interface. The impact of cementite is highlighted in terms of morphology of the CPL and corrosion mechanism.

Keywords: cementite; iron; magnetite; sidetire; steel

Domains: Material chemistry

Hélène Lotz, Delphine Neff, Florence Mercier-Bion, Christian Bataillon, Philippe Dillmann, et al.. Iron and steel corrosion mechanisms in a carbonate rich pore water: Multiscale characterization of the corrosion product layers. Materials and Corrosion / Werkstoffe und Korrosion, 2023, ⟨10.1002/maco.202213417⟩. ⟨cea-03769936⟩