Corrosion at the carbon steel-clay compact interface at 90°C: Insight into short- and long-term corrosion aspects

M.L. Schlegel (1) , F. Martin (2) , M. Fenart (2) , C. Blanc (1) , J. Varlet (1) , Eddy A Foy (3, 4) , D. Prêt (5) , N. Trcera (6)

1 SEARS - Service d'études analytiques et de réactivité des surfaces
2 SCCME - Service de la Corrosion et du Comportement des Matériaux dans leur Environnement
3 IRAMAT-CEB - IRAMAT - Centre Ernest Babelon
4 LAPA - UMR 3685 - Laboratoire Archéomatériaux et Prévision de l'Altération
5 Université de Poitiers - Faculté de Sciences fondamentales et appliquées
6 SSOLEIL - Synchrotron SOLEIL

Rods of low alloy carbon steel were corroded under anoxic conditions in compact clay at 90 °C. Gravimetrically-assessed corrosion damage equalled 8.5 μm at 7 months, then slowly increased to 29.5 μm at 76 months. The corrosion damage was heterogeneous at 7 months, and two distinct aspects coexisted: steel was replaced by (Fe,Si,O) corrosion products in some areas, and by Si-poor hydroxide and covered by akaganeite (FeO(OH,Cl)) in others, indicating corrosion in suboxic conditions. A magnetite fringe contacted the steel surface. For greater reaction times, akaganeite disappeared, and only (Fe,Si,O) corrosion products containing Fe sulfide and chukanovite were detected.

Domaines: Chimie

M.L. Schlegel, F. Martin, M. Fenart, C. Blanc, J. Varlet, et al.. Corrosion at the carbon steel-clay compact interface at 90°C: Insight into short- and long-term corrosion aspects. Corrosion Science, 2019, 152, pp.31 - 44. ⟨10.1016/j.corsci.2019.01.027⟩. ⟨hal-03486966⟩