Inhibition of Microbiologically Influenced Corrosion of 304 Stainless Steel by Artemisia annua L. in Simulated Seawater

The combination of electrochemical, surface, and spectroscopic techniques revealed that Pseudomonas aeruginosa biofilm accelerated corrosion of 304 stainless steel (SS), leading to localized pitting with depths up to 3.75 μm. Such damage did not occur on 304 SS treated with P. aeruginosa in the presence of Artemisia annua L. extract, or in sterile seawater. Introducing A. annua into biotic seawater hindered biofilm development and prevented the formation of porous Fe(III) corrosion products. Instead, a compact Fe3O4 layer formed, indicating a shift in corrosion product morphology and stability. ATR-FTIR analysis confirmed phenolic groups from the extract were adsorbed onto the steel interface, supporting the dual inhibitory role of A. annua through both surface modification and antimicrobial action. A. annua extract demonstrated a 74.4 ± 4.4% reduction in MIC-induced corrosion of 304 SS in marine conditions.