Role of alloying elements on the cytotoxic behavior and corrosion of austenitic stainless steels

Super stainless steel has been used to solve corrosion problems of biomaterials because it shows the excellent corrosion resistance as like Ti and Ti alloys and has better mechanical properties than Ti and Ti alloys. We designed high Mo and Ni bearing super austenitic stainless steel. To obtain desirable microstructure, Cr, Ni, Mo, N contents were controlled. This work focused on the role of alloying elements on cytotoxic behavior and corrosion of stainless steel. In acidic chloride solution, when the alloys had high PRE values, the alloys showed high pitting resistance and low critical current density. However, in Hanks' solution, the higher PRE's alloys showed high critical passive current density. Namely, it was revealed that EDTA among Hanks' solution played an important role to increase the critical passive current density of high Mo and Ni bearing super stainless steels, regardless of PRE's value of the alloys. Therefore, even if the PRE values of the alloys were higher, high Ni and Mo bearing alloys would reveal more cytotoxic and high metal ion release rate than 316L stainless steel.