N-acetyl cysteine based corrosion inhibitor formulations for steel protection in 15% HCl solution

The corrosion inhibition of steels in 15% HCl solution by N-acetyl cysteine (NAC) based formulations at different temperatures (30–90 °C) was studied. Gravimetric and electrochemical techniques complemented by surface morphology analysis were employed for the investigation. Results obtained show that without inhibitor, the steels corroded in the order J55 > mild steel > X80 steel. Addition of NAC based formulations reduced their corrosion rates significantly. Potentiodynamic polarization studies revealed that NAC acts as mixed type inhibitor with predominant influence on anodic reaction. NAC based formulations yielded inhibition efficiencies up to 91% at 90 °C and compared favorably with two commercial inhibitors tested under the same conditions. The formulations investigated can be deployed in practical field conditions to reduce metal corrosion.