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

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

Indexed on: 15 Mar '16Published on: 03 Sep '15Published in: Arabian Journal of Chemistry


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.

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