Pitting corrosion behavior and mechanism of 316L stainless steel induced by marine fungal extracellular polymeric substances

In this study, effect of extracellular polymeric substances (EPS) secreted by fungus Aspergillus terreus on the pitting corrosion of 316L stainless steels (SS) was deeply investigated by electrochemical measurements and surface analysis. Results demonstrated that adsorption of EPS can change surface wettability of 316L SS leading to a much more hydrophilic steel-water interface. EPS not only accelerates uniform corrosion but enhances pitting corrosion of 316L SS. EPS can promote the formation of metastable pitting corrosion and the subsequent growth of corrosion pits. The density of corrosion pits (>2 mu m) reach (5.6 +/- 0.5) x 10(3) pits/cm(2) when EPS is 400 mg/L.

Automated summary

This study investigated the impact of extracellular polymeric substances (EPS) secreted by Aspergillus terreus fungus on the pitting corrosion of 316L stainless steels through electrochemical measurements and surface analysis. The results demonstrated that EPS adsorption can alter the surface wettability of the steel, leading to a more hydrophilic steel-water interface. EPS not only accelerates uniform corrosion but also enhances pitting corrosion, promoting the formation and growth of corrosion pits.