Copper tracing to determine the micrometric electronic properties of a thick ferrous corrosion layer formed in an anoxic medium

In anoxic carbonated environments, the corrosion layer formed on iron is composed of magnetite and ferrous carbonates with different distributions, influencing the electronic properties of the whole layer. This study aims at determining at a micrometric scale the electronic properties of such corrosion layers, with a reaction tracing based on the use of the Cu2+/Cu(0) redox couple. Experiments reveal that the electrons formed at the metallic interface are available everywhere in the pores of a thick corrosion layer. This result is of importance to elucidate the corrosion mechanisms because it implies a decoupling of the anodic and the cathodic reactions.

► Corrosion mechanisms in anoxic carbonated media. ► Cu2+/Cu(0) tracing. ► Determination of the electronic properties of the corrosion layer. ► Decoupling of the cathodic and anodic reactions.