Pourbaix diagrams

• pourbaix diagrams:

  -diagrams to show the corrosion behaviour of a metal in a solution as a function of potential E & Ph

  -H+ is an active agent to corrosion

  -E-ph diagram to express corrosion behaviour of metals with oxidation force and acidity
• Vertical = only H+

  Horizontal=only e-

  sloping= H+ and e-
• immunity= corrosion cannot occur

  thermoynamically stable
• passive= corrosion does not occur(protected)