Experimental investigations on iron corrosion products formed in bicarbonate/carbonate-containing solutions at 90°C.

S. SAVOYE , L. LEGRAND, G. SAGON, S. LECOMTE, A. CHAUSSE, R.MESSINA, P. TOULHOAT Corrosion Science 43 (11) pp. 2049-2064.

The nature and the evolution of corrosion products formed on iron in bicarbonate/carbonate solutions at 90°C were investigated through FTIR, Raman spectrometry and scanning electron microscopy. It has been shown that the initial oxygen level directly influenced the reaction pathway and consequently the nature of iron oxides formed on iron surface. Intermediate compounds such as Green rust GR1 (C03) and amFe(OH)3 with adsorbed bicarbonate or carbonate ions were especially evidenced in the case of anaerobic conditions, whereas for slightly aerobic conditions, magnetite or/and siderite tend to form directly on iron surface.