Normally, zinc serves as the anode and protects steel, which acts as the cathode. During potential reversal, these roles switch: steel becomes the anode and corrodes before the zinc. Although some conditions for this phenomenon have been identified, they are not fully understood. Temperature, pH, and specific ions in water or soil are believed to play key roles.

Zinc maintains corrosion resistance below 50°C, but its corrosion rate rises sharply near 60°C, significantly reducing its protective effectiveness. In high-temperature and high-humidity environments, the rapid formation of zinc oxide (ZnO) and zinc hydroxide (Zn(OH)₂) destabilizes the material and triggers potential reversal. As a result, zinc in the galvanized layer promotes, rather than prevents, steel corrosion.