Effect of 2-acetyl-L-cysteine on the electrochemical properties of carbon steel for oil pipeline applications

This study investigates the corrosion inhibition performance of 2-acetyl-L-cysteine (NAC) for X80 steel using polarization, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The optimal inhibition efficiency was achieved under the conditions of T=313 K, pH=4, and NAC concentration of 0.5 mmol/L, by evaluating the effects of ambient temperature and inhibitor concentration. The inhibition efficiency initially increased and subsequently decreased with rising NAC concentration. Adsorption thermodynamics analysis revealed that NAC adsorption on X80 steel follows the Langmuir isotherm model. SEM and XPS results demonstrated that the addition of 0.5 mmol/L NAC significantly improved surface smoothness of X80 steel, confirming the formation of a protective adsorption layer. This study provides theoretical insights for the application of amino acid derivatives as environmentally friendly corrosion inhibitors.