Corrosion Inhibition of AISI 1020 Steel in 3 % NaCl Solution Using Some Environmentally Friendly Inhibitors

Metal corrosion control is an important for technical, economic, environmental, and aesthetic reasons. Inhibitors are one of the most effective ways to protect metals and alloys against corrosion. Over the last few years, material scientists have been particularly interested in the development of new ecologically friendly inhibitors (green inhibitors) for corrosion protection of metallic surfaces. In the present work, electrochemical measurements, XRF, XRD, and metallography were used to evaluate the corrosion behaviour of AISI 1020 steel in 3 % NaCl solution in presence of organic inhibitors such as tannic acid, polyethylene glycol, and quaternary amine. Results showed that tannic acid, polyethylene glycol, and quaternary amine are effective environmentally friendly inhibitors for AISI 1020 steel in 3% NaCl solution, by forming a protective coating film and inhibiting the accessible reaction sites exposed to the corrosive media. The inhibition efficiency increased by increasing the concentration of tannic acid, polyethylene glycol, and quaternary amine up to 40, 250, and 75 ppm respectively. Furthermore, 40 ppm of tannic acid recorded the lowest value of corrosion rate compared with both quaternary amine and polyethylene glycol at their best inhibition efficiency concentrations. XRD results showed that elements like N, O, C, and S were adsorped on the surface of steel. These were verified by XRF analysis, as these element made compounds on steel suface. A clearly-apparent protective layer on the surface was investigated by SEM. Such a type of these green inhibitors could have a promising candidate for possible industrial applications.