Investigation on mechanical, corrosion resistance and antibacterial properties of Cu-bearing 2205 duplex stainless steel by solution treatment

In this study, the effect of solution temperature on the mechanical properties of the 2205-Cu duplex stainless steel (DSS) was investigated by metallographic observations and tensile tests at room temperature. The corrosion resistance and antibacterial performance of the 2205-Cu DSS were studied by electrochemical potentiodynamic polarization and electrochemical impedance spectroscopy in artificial sea water and co-cultured with Marinobacter salsuginis. X-ray photoelectron spectroscopy was used to analyze the compounds formed on the surface of the specimens. The results showed that the tensile strength and yield strength of 2205-Cu DSS increased slightly with an increase in solution temperature. Correspondingly, due to the minor enhancement of ferrite content, both the pitting corrosion potential and antibacterial property were improved. This was mainly attributed to the surface enrichment of Cr₂O₃, Cr(OH)₃ and Cu and to the decreased uniform corrosion resistance, which stimulated the release of more Cu²⁺ ions and resulted in improved antibacterial properties.