Corrosion Inhibition of Organic Oil Extract of Leaves Of Lanvandula Stoekas on Stainless Steel in Concentrated Phosphoric Acid Solution

The Corrosion inhibition effect of organic oil of leaves of Lanvandula stoekas [L] on corrosion of alloy UB6 stainless steel in 5.5 M H3PO4 solution was carried out using electrochemical polarisation and EIS methods. Experiments are performed by varying concentration of the inhibitor and temperature. The inhibition efficiency increases with increased organic oil concentration to attain a maximum value of 87.3 % at 1.2 g/L. The study reveals that [L] acts as a mixed inhibitor and showed a result of the growth in the compactness of the protecting film dressing. The inhibition efficiency of organic oil is temperature-dependent in the range 293 - 353 K, the associated activation energy has been determined. The organic oil [L] adsorbs on the stainless steel surface according to a Langmuir isotherm adsorption model.