Thermodynamic basis of antagonistic effects of oxygen and sulphur on corrosion of passivating metals

A thermodynamic basis is used to explain why some metals are prone to develop a resistant passivation layer whereas some are subject to S-induced corrosion. We revisit the correlations between formation enthalpies of adsorbed (2D) and bulk (3D) compounds, both for the M-O and the M-S systems. Then we plot S adsorption enthalpy versus O adsorption enthalpy. This plot allows us to classify the various metals according to their capacity to adsorb rather O or S. Applied to corrosion science and engineering, this work should help predicting the resistance of metals and alloys to corrosion induced by environmental sulphur.

Automated summary

This study uses a thermodynamic basis to explore the adsorption capabilities of metals towards oxygen or sulfur, aiming to predict the resistance of metals and alloys to corrosion induced by environmental sulfur.