Corrosion risk of steel

Cu/CuSO₄

Ag/AgCl (4M KCl)

Corrosion condition

E ≥ −200 mV

E ≥ −106 mV

Low (<10% risk)

−350 mV to −200 mV

−106 mV to −256 mV

Uncertain (intermediate risk)

E < −350 mV

E < −256 mV

Very high (>90%)

E < −500 mV

E < −406 mV

Severe