Pourbaix Diagram Calculator

Analyze metal stability as a function of pH and electrode potential. Determine corrosion, passivation, and immunity regions.

Pourbaix Analysis Parameters

Water Stability Lines:

H2/H2O: E = -0.0591 * pH

O2/H2O: E = 1.23 - 0.0591 * pH

Stability Region

Corrosion

Dominant Species: Fe2+ / Fe3+

pHpH
7.0
EE (vs SHE)
0.00 V
H2H2 Line
-0.414 V
O2O2 Line
0.816 V

Corrosion

Active dissolution of metal occurs

Recommendations:

  • - Active corrosion expected
  • - Apply cathodic protection
  • - Use corrosion inhibitors

Water Stability:

Within water stability region

Understanding Pourbaix Diagrams

Immunity

Metal is thermodynamically stable. No corrosion occurs.

Passivation

Protective oxide layer forms on metal surface.

Corrosion

Metal actively dissolves as soluble ions.