Microbiological influenced corrosion resistance characteristics of a 304L-Cu stainless steel against Escherichia coli

Cu-bearing antibacterial stainless steels have been gaining popularity in recent years due to their strong antibacterial performances. However, only a few studies were reported for their actual performances against microbiologically influenced corrosion (MIC). In this study, electrochemical methods and surface analytical techniques were applied to study the MIC resistance characteristics of a 304L-Cu stainless steel (SS) against Escherichia coli in comparison with 304L SS as control. Corrosion tests for specimens after a 21-day exposure to a Luria–Bertani (LB) culture medium with E. coli demonstrated that the 304L-Cu SS considerably reduced the maximum MIC pit depth and the specific weight loss compared with 304L SS (8.3 μm and 0.2 mg/cm2 vs. 13.4 μm and 0.6 mg/cm2). Potentiodynamic polarization tests showed that the corrosion current density of the 304L-Cu SS was as much as 4 times lower than that of the 304L SS, indicating that the 304L-Cu SS is a better choice for applications in MIC-prone environments.