Insights into the influence of cold rolling and accelerated isothermal aging on microstructure evolution, corrosion performance, σ precipitation and its kinetics in a low molybdenum Fe-21Cr-5Mn-1.5Ni alloy

In the present work, effect of cold rolling and accelerated isothermal aging at 800 °C on the microstructural changes and corrosion behavior in a low molybdenum Fe-21Cr-5Mn-1.5Ni alloy has been investigated. Scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and electron backscattered diffraction (EBSD) were used to investigate the changes in microstructure and σ precipitation, while the corrosion behavior was studied using anodic polarization tests and electrochemical impedance spectroscopy (EIS). The corrosion resistance followed the given sequence – Solution annealed (undeformed) > 50% cold rolled + aged 72 h > solution annealed (undeformed) + aged 72 h > 50% cold rolled. Corrosion products were mainly oxides of iron and chromium.