Influence of Temperature on the Corrosion Behavior of 18Mn-18Cr Austenitic Stainless Steel in 3.5 wt.% NaCl Solution

18Mn-18Cr austenitic stainless steels (P900) are usually applied in manufacturing of rotors and coil retaining rings, which may be served in a high temperature environment. In this paper, the influence of temperature on the corrosion behavior of 18Mn-18Cr austenitic stainless steel in 3.5 wt.% NaCl solution has been investigated by the OCP monitoring, potentiodynamic polarization, potentiostatic polarization, electrochemical impedance spectroscopy (EIS) and Mott-Schottky analysis. Results show that the general corrosion resistance and pitting corrosion resistance of 18Mn-18Cr austenitic stainless steels would both decrease with the increase of temperature, based on that the decreased values of E-ocp, E-corr E-pit, i(corr) and impedance. Besides, the pitting incubation period of 18Mn-18Cr austenitic stainless steels is sensitive to the temperature (about 1711 s at 40 degrees C and less than 100s at 45 degrees C). In addition, the passive films formed on 18Mn-18Cr austenitic stainless steel exhibit n-type semiconductor characteristic. The donor concentrations (N-D) increase with the increase of temperature, which results in the reduced corrosion resistance at a higher temperature.