Influence of crystallographic textures on the hydrogen embrittlement resistance of austenitic stainless steel

Hydrogen embrittlement (HE) resistance is a significant concern in austenitic stainless steel (ASS) used for hydrogen transportation and storage. While microstructure-controlled methods to enhance HE resistance have been extensively studied in ferritic steels, comprehensive research on microstructure effects in ASS is lacking. In this study, two 316L ASSs with different microstructures were evaluated for HE resistance using electrochemical hydrogen charging. The steel with abundant in <111>+<110> orientations showed a significant elongation reduction after hydrogen charging. It revealed that, from the hydrogen permeation and thermal desorption analysis (TDA) results, effective diffusivity and activation energy of hydrogen were changed along the crystallographic orientation distributions. Also, transformation induced plasticity (TRIP) and twinning induced plasticity (TWIP) behavior affecting to the HE resistance preferentially formed in grains with <111> and <110> orientations rather than in those with <001> orientation during plastic deformation. Therefore, the study suggests that reinforcing the <001> microstructure is advantageous for improving HE resistance in 316L ASS.