Bridge for thermodynamics and kinetics of electrochemical corrosion: Cathodic process with a complex equilibrium and deposition competition

The dissolution-ionization-diffusion-deposition (DIDD) model is corrected by a cathodic process with the feature of complex equilibrium and deposition competition. CO2/H2S corrosion of steel is taken as an example to better understand whether the main factor controlling the corrosion is CO2, H2S or both. The preliminary assessment reveals that when the rate of nuclei is less than 10 % of the total, the corrosion is controlled by only one factor. Furthermore, the calculated results also have a good agreement with morphology and weight loss experiments. This study makes a significant contribution to promoting the application of DIDD model.