Anti corrosion and anti-pit resistant munj extract inhibitor for DSS 2205 in chloride contaminated solutions

Corrosion is the major issue in process industries, causing failure of process equipment due to structural degradation. This can be reduced by protective coating on equipment. In this study, Duplex Stainless Steel (DSS2205) is exposed to a 3.5% brine solution, and munj plant extract was prepared and utilized as a green corrosion inhibitor in various concentrations. The corrosion rate of DSS2205 sample coupons was analyzed by electrochemical techniques such as LPR and EIS. The surface of the exposed samples, with and without inhibitors, is examined using FESEM, EDS and XRD. Munj extract inhibitor acts well for DSS2205 in brine conditions. The results show 87% efficiency of munj extract of DSS2205 at an optimum concentration of 5% vol/vol concentration exposed for 24 h. FESEM analysis shows that the inhibitor covers and protects the surface of the sample. FT-IR analysis shows the presence of alcoholic, alkanes functional groups. GC-MS analysis of the extract confirms the presence of docosenamide compound, which is responsible for carrying inhibiting properties. DFT calculations were used to examine the adsorption of the CONH₂ functional group, derived from docosenamide, on Fe 2 O 3 (100) and (110) surfaces. Strong chemisorption was observed on the Fe 2 O 3 (110) surface, whereas adsorption on the (100) surface was energetically unfavorable, highlighting a pronounced surface-orientation dependence. These results provide atomistic insight into the role of iron-oxide surface structure in governing amide-based corrosion resistance.