Effect of marine Pseudoalteromonas sp. on the microstructure and corrosion behaviour of 2205 duplex stainless steel

• The effect of Pseudoalteromonas sp. on the corrosion behaviour of 2205 DSS is studied.
• A strong negative shift in potential is observed during bacterial attachment.
• Bacteria induce a localised attack by decreasing Cr and accumulating Cl− on DSS.
• Enzymatic activities produce high K and Cl contents on the DSS surface.

The effects of isolated marine Pseudoalteromonas sp. on the microstructure and corrosion behaviour of 2205 duplex stainless steel were investigated using electrochemical and surface analysis methods. Electrochemical studies demonstrated a negative shift in corrosion potential and an increase in corrosion current density in the presence of bacteria. EDS results showed a high concentration of chloride ions in the biofilm structure and a decrease in Cr content beneath the biofilm layer and near cracks. These results could lead to localised corrosion on metal surfaces. FESEM images illustrated the process of bacterial attachment on the metal surfaces at different exposure times.