Long Term Behaviour of Iron in Clay Soils: A Study of Archaeological Analogues
E. Pons, L. Uran, S. Joiret, Anne Hugot‐Le Goff, C. Lemaître, Daniel David · 2024
Iron objects from a battlefield of World War I were studied to obtain a better understanding of corrosion phenomena in clay soils. The identification of the corrosion products by Raman Spectroscopy highlighted iron oxides and oxy-hydroxides. The orange–brown external layer is composed of oxy-hydroxides, mixed with soil crystals, while the oxides are always associated with the internal layer. Electrochemical experiments (Voltammetry and Electrochemical Impedance Spectroscopy) in Evian mineral water (pure or with sodium chloride), confirmed the porosity of the external layer, and the protective role of the internal products. The influence of the burial environment on the corrosion rate was also established.