Computational approach for mechanisms of hydrogen absorption into metal

Igarashi, Takahiro  ; Otani, Kyohei   ; Ueno, Fumiyoshi  

Hydrogen embrittlement is one of cause of decrease in the strength of steel due to hydrogen into steel. Although much research has been conducted on the hydrogen embrittlement, the detailed mechanism has not been surely understood yet. In this study, first we assumed that cations in aqueous solution inhibit the hydrogen penetration path to iron, adsorption potential of each metal cation on iron surface were analyzed by first principle calculation with solution approximation. As a result, various cation adsorption potentials were larger in order of Na, Mg, Zn and Al. It was suggested that inhibition ability of hydrogen permeation improves in the order of Na, Mg, Zn and Al. By density of state analysis, it was suggested that the adsorption potential of cation was related to the presence of the combined hybrid orbital generation between cation and Fe.