Investigation of the adhesion performance of drag reducer and inhibitor on carbon steel surfaces in flow conditions

This study aims to investigate the adhesion properties of hydrolyzed polyacrylamide (HPAM) and imidazoline molecules on carbon steel surfaces under flow conditions. The effect of flow rate on corrosion inhibition of carbon steel was investigated using rotating cylindrical electrode, electrochemical techniques and surface analysis. The results demonstrate that under high-turbulence conditions (Re > 17,700), the synergistic combination of HPAM and imidazoline enhances corrosion inhibition efficiency by 58.69% compared to the standalone imidazoline system. Electrochemical impedance spectroscopy (EIS) reveals a 2.3-fold increase in charge transfer resistance for the HPAM-imidazoline system compared to imidazoline alone at 2 m/s, confirming the formation of a denser and more stable protective film. SEM analysis corroborates this, showing a reduction in localized pitting corrosion due to HPAM’s turbulence modulation and enhanced co-adsorption. The synergy arises from HPAM’s ability to suppress wall shear stress by absorbing turbulent eddy energy and chemically anchor imidazoline molecules via Fe–N coordination, ensuring sustained film integrity under dynamic flow. This dual-action mechanism offers a novel solution for mitigating flow-accelerated corrosion (FAC) in industrial pipelines.