Direct comparison of C and N effect on hydrogen embrittlement of stable 17Cr-10Ni-6Mn austenitic stainless steel

Abstract

The effects of C and N on hydrogen embrittlement (HE) were investigated in 17Cr-10Ni-6Mn based stable austenitic stainless steels containing 0.2 wt% of either C or N. C and N increased tensile strength by solid solution hardening and high-density dislocation accumulation. C was more effective on further strengthening by active TWIP effect than N. The lattice expansion by C and N decreased hydrogen diffusivity and depth of hydrogen-affected zone, which increased the HE resistance. The HE resistance was further enhanced by C than N due to lower hydrogen diffusivity and crack severity and active cross slip by C.