Study on Electrochemical Behavior at a Room and High Temperature at 700 °C Corrosion of Austenite, Ferrite, and Duplex Stainless Steels

The stainless-steel phase of austenite, ferrite, and duplex was affected by the high temperature corrosion. So, the study of corrosion behavior in high temperatures at 700 °C is important because it is connected to life and maintenance. Various stainless steels (AISI no. 409 L, 430 L, 304L, 316L, 2205, 2507) are used to identify the most suitable material for high-temperature SOFC applications. The study was checked to surface, microstructure, and corrosion behavior after corrosion at 700 °C during 120 h. The surface and microstructure are checked using FE-SEM and XRD. The electrochemical behavior and corrosion behavior are checked for open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization test by a potentiostat. The potentiodynamic polarization results revealed that the pitting potential (Epit) varied significantly depending on the material, with values of 0.21 V for AISI 304L and 1.14 V for AISI 2507. The breakdown behavior of the passive film exhibited material-dependent characteristics, which were found to be consistent with the observed trends in high-temperature corrosion.