Hydrogen-enhanced deformation twinning in Fe-Cr-Ni-based austenitic steel characterized by in-situ EBSD observation

Direct evidence of solute hydrogen-assisted deformation twinning in Fe-24Cr-19Ni-based austenitic steel was acquired via an in-situ tensile test in a scanning electron microscope (SEM) equipped with electron backscattered diffraction (EBSD). Earlier activation of twinning on both primary and secondary systems by hydrogen was successfully visualized, in addition to recognizing an accelerated thickening of the existing twins. These alterations in twinning behavior were linked to an increase in the work-hardening rate at the later deformation stage, which is believed to be a root cause of recently discovered anomalous ductility improvement in the steels under the presence of solute hydrogen.