PT Journal AU Lebrini, M Robert, F Lecante, A Roos, C TI Corrosion inhibition of C38 steel in 1 M hydrochloric acid medium by alkaloids extract from Oxandra asbeckii plant SO Corrosion Science JI Corrosion Sci. PY 2011 BP 687 EP 695 VL 53 IS 2 DE Steel; EIS; Polarization; Raman spectroscopy; Acid inhibition AB The inhibition effect of alkaloids extract from Oxandra asbeckii plant (OAPE) on the corrosion of C38 steel in 1 M hydrochloric acid solution has been investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The corrosion inhibition efficiency increases on increasing plant extracts concentration. Cathodic and anodic polarization curves show that OAPE is a mixed-type inhibitor. The effect of temperature on the corrosion behavior of C38 steel in 1 M HCl with and without addition of plant extract was studied in the temperature range 25-55 degrees C. The thermodynamic functions of dissolution and adsorption processes were calculated from experimental polarization data and the interpretation of the results are given. The adsorption of this plant extract on the C38 steel surface obeys the Langmuir adsorption isotherm. Surface analysis (Raman) was also carried out to establish the corrosion inhibitive property of this plant extract in HCl solution. (C) 2010 Elsevier Ltd. All rights reserved. ER