Stainless steels suffer from hydrogen embrittlement (HE) at low temperatures, thus the improvement of the resistance to HE has been expected by alloying. The main elements of Ni and Cr improve resistance to HE by stabilizing austenite phase with respect to martensitic transformations and by increasing the stacking fault energy (SFE) to promote cross-slip. The addition of N also stabilizes austenite phase and improves resistance to HE. Although N does not change the SFE, N promotes planar-slip by inducing a short range order in the matrix [
]. Thus, N and Ni play distinct roles in improving resistance to HE. It provides a way to distinguish HE due to strain-induced alpha’ martensite from HE due to planar-slip.