Abstract
Improving pitting corrosion resistance of stainless steel304 by Lupine investigated in 0.5 M HCl solution using Weight loss measurements, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. The polarization results showed that Lupine extract act as anodic -type inhibitor with a high protection efficiency of 92% at extract addition of 15 ppm. EIS measurements showed that the dissolution process of stainless steel occurs under diffusion control. The adsorption behavior of the main Lupine extract constituents on stainless steelsurface was well described following Flory-Huggins isotherm and Kinetic-Thermodynamic model. Surface studies using SEM-EDX techniques supported the obtained chemical and electrochemical results