Effects of Nitrogen on Microstructure, Mechanical Properties and Corrosion Behavior in Nickel-Free Austenitic Stainless Steels

Different amounts of nitrogen were added to nickel-free high manganese austenitic stainless steels with addition of a nitrided ferroalloy. The microstructure was evaluated by optical microscopy and the mechanical properties were determined by macro-hardness and tensile tests. The corrosion behavior was evaluated by electrochemical impedance spectroscopy and polarization. The results showed that the microstructure of high nitrogen and low nitrogen steels were austenite and ferrite and austenite, respectively. The hardness, yield strength and ultimate tensile strength of the steels increased with increasing nitrogen content. In addition, corrosion current densities decreased and corrosion potentials shifted to more positive values with increasing nitrogen content.