CORROSION INHIBITION STUDY OF Cratevaadansonii PLANT EXTRACT ON MILD STEEL IN ACIDIC MEDIA

Abstract

Abstract A study on the inhibitive properties of Cratevaadansonii plant extracts on mild steel in 1.75 M HCl was embarked upon in this research using gasometric and potentiodynamic polarization technique at room temperature. The mild steel coupons were immersed in blank of 1.75 M HCl and the procedure repeated for the various extract concentrations of 10% - 50% v/v. The amount of hydrogen gas evolved due to the reaction between acidic extract and the mild steel coupons were evaluated. The observed inhibition efficiency using gasometric method indicated a direct relationship with increase in concentration of the inhibitors up to 50% concentration for both extracts. A similar trend was observed in the Tafel plot using the polarization technique. The adsorption study revealed the use of Cratevaadansoniiextract obeyed the Freundlich isotherm which characterizes physisorption. The use of Cratevaadansoniiextractis hereby proposed a suitable inhibitor for the corrosion of mild steel in acidic media.