THERMODYNAMICS OF HIGH TEMPERATURE AQUEOUS CORROSION.

Thermodynamic equilibrium in metal-water systems are best represented by potential-pH diagrams. In this work extension of potential-pH diagrams at temperatures above 25 degree C and thus the thermodynamic equilibria in metal-water systems at these temperatures were investigated with the view of utilizing such an approach to explain the corrosion of metals in aqueous environment. The thermodynamic equilibria relations driven were demonstrated with potential-pH diagrams of various metal-water systems such as: Fe-H//2O, Al-H//2O and Ni-S-H//2O at temperatures up to 300 degree C.