The Contribution of Cr and Ni to hydrogen absorption energy in Fe-Cr-Ni austenitic systems; A First-principles study

Moriyama, Junichiro*; Takakuwa, Osamu*; Yamaguchi, Masatake   ; Ogawa, Yuhei*; Tsuzaki, Kaneaki*

The present study focuses on a novel hydrogen-improved strength-ductility balance in some practical Fe-Cr-Ni-based austenitic alloys, which directly depends on the solute hydrogen content. The hydrogen absorption energy of the Fe-Cr-Ni model alloys with the face-centered cubic structure was examined using first-principles calculations to verify the contribution of Cr and Ni substitutions from Fe to the hydrogen solubility in the alloys. The Cr substitution substantially reduced the hydrogen absorption energy compared to the Ni substitution, whereby the increased Cr/Ni ratio exerts higher hydrogen solubility. The propensity in the calculations coincided with the experimental results obtained previously in the practical alloys with various Cr / Ni ratios.