What Does Protection Potential Mean?
Protection potential is the electrode potential at which corrosion may be halted by keeping the electrode potential below a given critical value.
This can be used to prevent:
- Pitting corrosion
- Stress-corrosion cracking
- Intergranular corrosion
- Crevice corrosion
Corrosionpedia Explains Protection Potential
Metals in the passive region, when exposed to oxidizing halide environments or hydrogen chloride acid environments, can suffer from pitting and crevice corrosion because the potential of the electrode exceeds the protection potential. This can be reduced by the application of a direct current to the metal, shifting potential from the transpassive region back to the passive region.
Maintaining metals in a passive state is vital for corrosion protection.