Evaluation of vegetable oil of nigel as corrosion inhibitor for iron in NaCl 3% medium

For protecting the metals such as iron in aqueous medium,inhibitors based on vegetable oils show adequate protective powers. they can find numerous applications in various industries due to their environment friendly nature,biodegradability and absence of heavy metals or toxic chemicals in them. the present work concern an evaluation of vegetable oil of nigel as corrosion inhibitor for iron in a marine environment (the seawater is equivalent to 3% by weight sodium chloride: nacl 3%,from the point of view of an ionic strength solution). vegetable oil extract of nigel is biodegradable and environmentally friendly. the influence of the concentration on the corrosion process in the absence and presence of inhibitor was studied by electrochemical measurements including free and polarization curves potential. the polarization curves showed a decrease in the density of anodic and cathodic currents as a function of the concentration,this extract acts as a mixed inhibitor forming a protective layer on the metal surface. the results on the influence of concentration showed that the maximum efficiency is obtained at a concentration of 6 g / l,with a percentage of 99.84%,and therefore reducing significantly the corrosion rate.