The electrochemical behaviour of iron in stagnant and stirred potassium carbonate-bicarbonate solutions in the 0–75°C temperature range

Abstract

The corrosion and passivation of polycrystalline iron electrodes in carbonate-bicarbonate solutions are studied in the 0–75°C temperature range. The influence of the solution ionic strength, stirring velocity, and potential scan rate on the electrodissolution of the base metal and the formation of both the prepassivating and the passivity surface layers are considered. The chemical dissolution of the prepassive film and the electroformation of the different surface compounds are discussed in terms of a complex reaction pathway involving both simultaneous and consecutive stages including the corresponding ionic equilibria.