Influence of flow velocity on carbon steel corrosion in strong acids: experimental quantification and Tafel–Piontelli model improvement

processes including acidizing, pickling, and chemical cleaning involve highly acidic electrolytes under flowing conditions. The mechanistic Tafel–Piontelli (TP) model, previously presented at the Eurocorr conference and used for corrosion rate prediction, does not explicitly account for electrolyte flow velocity, potentially limiting its predictive accuracy under field-representative hydrodynamic conditions. Increasing flow velocity can potentially accelerate corrosion and induce measurable shifts in both corrosion potential and corrosion current density due to enhanced cathodic mass transport. In this work, the effect of flow velocity on carbon steel corrosion in strong acidic environments was investigated using a rotating cylinder electrode (RCE) to impose well-controlled hydrodynamic conditions. Corrosion behavior was characterized by potentiodynamic polarization (PDP) and linear polarization resistance (LPR) measurements, and independently validated through mass loss experiments. The results quantitatively describe the evolution of corrosion potential and corrosion current density as functions of flow velocity, pH and temperature, providing the experimental foundation necessary for incorporating flow effects into TP-based corrosion prediction. The findings demonstrate that increasing hydrodynamic forcing leads to a pronounced increase in corrosion current density and, consequently, corrosion rate. This velocity dependence becomes more significant at elevated temperatures, where kinetic and mass transport effects act synergistically to accelerate corrosion. Overall, the results establish both the mechanistic understanding and experimental basis for extending the TP framework to include flow velocity, enabling more reliable corrosion rate predictions under field-relevant operating conditions