Investigation of microbiologically influenced corrosion of high nitrogen nickel-free stainless steel by Pseudomonas aeruginosa

• The MIC behavior of nickel-free HNS in the presence of Pseudomonas aeruginosa is investigated.
• The pitting corrosion of HNS is greatly accelerated by the P. aeruginosa biofilm.
• The probability analysis confirms the pitting acceleration of HNS by the P. aeruginosa biofilm.

High nitrogen nickel-free stainless steel (nickle-free HNS) has been widely used in recent years because of its strong corrosion resistance. However, little is known on its resistance to microbiologically influenced corrosion (MIC). This study investigated the MIC behavior of nickel-free HNS in the presence of marine aerobe Pseudomonas aeruginosa. A 14-day corrosion test demonstrated that the HNS had a largest pit depth of 16.2 μm, over three times deeper than that of the abiotic control coupon (4.7 μm). Electrochemical tests and surface morphology examination confirmed that HNS was susceptible to MIC.