Corrosion protection of N80 steel in hydrochloric acid by substituted amino acids

Abstract

In the present investigation, corrosion inhibition study of two synthesised amino acid compounds 2-amino-N-dodecylacetamide (ADA) and 2-amino-N-dodecyl-3-(4-hydroxyphenyl) propionamide (ADHP) has been performed for oil well tubular steel (N80) in 15%HCl using weight loss, electrochemical polarisation, ac impedance, Fourier transform infrared spectroscopy and SEM. The inhibition efficiencies of the inhibitors follow the sequence ADHP>ADA. The results showed that the inhibition efficiency of inhibitors increased with the increase in their concentration in 15%HCl solution. Both inhibitors act as mixed inhibitors and obey the Langmuir adsorption isotherm. The adsorption of the corrosion inhibitors at the surface of the N80 steel is the root cause of its corrosion inhibition.