Corrosion products of reverse crevice corrosion of copper

Open-circuit potential measurements and Raman spectroscopy were used to investigate the reverse crevice corrosion phenomenon and its corresponding corrosion products. With the aid of these techniques, the existence of reverse-crevice corrosion in copper was verified, i.e., while the surface of a crevice was corrosion free, the outside surface of the copper was attacked. The processes associated with this phenomenon were classified into three phases, and different compositions of the corrosion products were determined. Raman spectra showed that copper and Cu₂O were found in the crevice, while CuO, Cu₂O, and CuCl₂ were the corrosion products on the bold surface. Based on these findings, a hypothesis relating to the three phases of reverse crevice corrosion has been proposed.