Phase transformations and microstructure evolutions during depressurization of hydrogenated Fe-Mn-Si-Cr alloy

Hydride formation and associated phase transformations have been extensively studied in pure Fe. However, the understanding of hydrogenation in Fe-based alloy systems is still lacking. Such an investigation is particularly important in the case of austenitic (face -centered cubic) steels given that hydrogen has been reported to alter the austenite phase stability. In the current work, we investigate the phase transformations associated with depressurization of non-hydrogenated and hydrogenated Fe-Mn-Si-Cr alloy (FMS) (Fe-28.84Mn-7.04Cr-6.14Si, in mass %) using in-situ x-ray diffraction technique. Additionally, we study the change in microstructure using electron backscatter diffraction (EBSD) and electron channeling contrast imagining (ECCI).(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.