Effect of microstructure on corrosion behavior of medium manganese steel

In this work, the corrosion behavior of medium-manganese steel (MMS), with lamellar and globular microstructure having comparable austenite and ferrite fractions is studied using potentiodynamic polarization and electrochemical impedance spectroscopy techniques. It was observed that lamellar morphology had superior corrosion resistance depicted by similar to 44 % lower corrosion current and a greater charge transfer resistance. The superior corrosion resistance of lamellar morphology was attributed to a relatively favorable crystallographic texture and a higher fraction of low energy low angle grain boundaries compared to globular morphology MMS. This work sheds important insights into controlling corrosion resistance of third-generation advanced high-strength MMS through microstructural design.