The self-sustaining propagation of crevice corrosion on the hybrid BC1 Ni-Cr-Mo alloy in hot saline solutions

The initiation and propagation of crevice corrosion on the BC1 nickel-chromium-molybdenum alloy has been studied galvanostatically in concentrated chloride solution at 120 °C, and the distribution of corrosion damage determined using surface analytical techniques. The distribution of damage was dependent on the applied current and showed an increased tendency to spread across the surface as the applied current was increased. Attempts to induce repassivation by galvanodynamically reducing the current to zero were unsuccessful. Galvanic coupling to a large BC1 counter electrode showed propagation could be maintained by oxygen reduction on the coupled electrode at a slow rate for >1200 h.