Abstract
Sweet corrosion of carbon steel is responsible for the majority of the corrosion failures in the oil&gas industry and it takes place when the metal is in contact with carbon dioxide in presence of water. The predictive models developed throughout the years to face this issue are mostly empirical or semiempirical. The scope of this work is to test the performance of the Tafel-Piontelli model, a mechanistic model designed to calculate the corrosion rate of active metals in acidic conditions, with particular focus on sweet corrosion of carbon steel. The model is validated in acidic solutions at different temperature and pH conditions. The experimental corrosion rates are determined from mass loss tests and compared to the predicted values, showing a good fit. Finally, the model is applied to the case of sweet corrosion of carbon steel through a benchmark analysis and a comparison with consolidated corrosion models: the De Waard-Lotz model (1993), the De Waard-Lotz-Dugstad model (1995), and the Cassandra model (1998). The results are promising and confirm the good applicability of the Tafel-Piontelli model to the prediction of CO2 corrosion.