Study of Valine as Green Corrosion Inhibitor for 304 Stainless Steel in Saline Solution

Abstract

The effectiveness of amino acid valine in preventing corrosion of 304SS in a sodium chloride (0.6 M NaCl) solution as a green inhibitor was investigated both with and without the organic inhibitor at temperatures between 298 and 328 K. With the use of the potentiodynamic polarization approach, the electrochemical performance related to the amino acid valine had been investigated. Using scanning electron microscopy (SEM), the metal surface was researched. The findings demonstrated that inhibition efficiency increased with inhibitor concentration increase but decreased as temperature increased. According to polarization measurements, valine has physically adsorbed on the stainless steel surface, is regarded as a cathodic inhibitor, and complies with the Langmuir adsorption isotherm. To illustrate the corrosion inhibition process, a few thermodynamic parameters like Gibbs free energy (∆G_ads) as well as activation energy (E_a) were calculated. The Arrhenius theorem has been used to assess the kinetic limitations. A suitable mechanism for the corrosion of stainless steel in saline solution had been predicted.