Arabian Journal of Chemistry (Dec 2019)

Electrochemical evaluation of cephalothin as corrosion inhibitor for API 5L X52 steel immersed in an acid medium

  • Jorge Aldana-González,
  • Araceli Espinoza-Vázquez,
  • Mario Romero-Romo,
  • Jorge Uruchurtu-Chavarin,
  • Manuel Palomar-Pardavé

Journal volume & issue
Vol. 12, no. 8
pp. 3244 – 3253

Abstract

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The corrosion inhibition efficiency, η, of sodium (6R,7R)-3-[(acetoxy)methyl]-8-oxo-7-[(2-thienylacetyl)amino]-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid, cephalothin, was evaluated in the system API 5L X52/1 M HCl, using electrochemical impedance spectroscopy and SEM analysis. The results showed that the inhibition mechanism involves blockage of the steel surface by the inhibitor molecules through a Langmuir-type adsorption process. The studies to determine the durability where the inhibitor remained effective showed that, at stagnant conditions, the η was maintained over 92% for up to 600 immersion hours at 50 ppm, reaching the best corrosion efficiency when temperature was 25 °C. Keywords: Electrochemical techniques, Corrosion inhibitor, Organic compounds, Adsorption