Enhancement of hydrogen embrittlement resistance in 310S austenitic stainless steel through ribbon-like δ-ferrite

In general, δ-ferrite phases, especially in the weld, are not conducive to the hydrogen embrittlement (HE) resistance of austenitic stainless steels (ASSs). However, it is interesting to note that if a ribbon-like δ-ferrite was introduced into ASS, its HE resistance can be improved. In this work, we take 310S ASS as an example and form a ribbon-like δ-ferrite on the original austenite grain boundary by quenching at 1200℃. This newly formed ribbon-like δ-ferrite phase not only alters the hydrogen enrichment characteristic from austenite grain boundaries to austenite/δ-ferrite interfaces but also contributes to an increased resistance to HE.