Effects of Cr2N Precipitation on the Antibacterial Properties of AISI 430 Stainless Steel

Abstract

Based on their mechanical properties and good corrosion resistance, some commercial Ni-Cr stainless steels have been widely applied as biomaterials, including the austenitic 304 stainless steel, the austenitic 316 stainless steel, the duplex 2205 stainless steel, and the ferritic 430 stainless steel. In order to reduce the occurrence of infections resulting from biomaterial implants, instruments, and medical devices, Cu 2+ and Ag 2+ ions have been added onto biomaterials for increasing the antibacterial properties, but they are known to damage biofilm. The occurrence of nanoparticles can also improve the antibacterial properties of biomaterials through various methods. In this study, we used Escherichia coli and analyzed the microstructures of American Iron and Steel Institute (AISI) 430 stainless steel with a 0.18 mass % N alloy element. During a lower temperature aging, the microstructure of the as-quenched specimen is essentially a ferrite and martensite duplex matrix with some Cr 2 N precipitates formed. Additionally, the antibacterial properties of the alloy for E. coli ranged from 3% to 60%, consistent with the presence of Cr 2 N precipitates. When aged at a lower temperature, which resulted in nano-Cr 2 N precipitation, the specimen possessed the highest antibacterial activity.

Plasma Electrolytic Polishing—An Ecological Way for Increased Corrosion Resistance in Austenitic Stainless Steels

“…With regard to the very low average corrosion rates (Table 7), only slight pitting corrosion attack related to the structural imperfections (e.g., inclusions visible in Figure 8) could be initiated. It points to the high corrosion resistance and biomedical safety with the minimum metal release into the human body environment [16,46,47] that correlates with the results of the performed independent electrochemical corrosion tests. Unlike these results, in the exposure test performed under the same conditions on the EP surface of 316L stainless steel, the authors [28] observed more pronounced pitting corrosion damage and higher corrosion rates (dependent on EP conditions 0.013-0.024 g/(m 2 •day)).…”

Investigation of the antibiofilm capacity of peptide-modified stainless steel

“…AISI 304 grade annealed stainless steel sheets with a thickness of 250 µm were purchased from Wuhan steel factory, which was studied for marine facilities and medical implants [18][19][20]. Stainless steel plates were cut into discs of Ø10 mm, and polished using 600# coast grit sandpaper before being modified by dopamine and peptides.…”