Effects of Alloying Elements on Hydrogen Diffusion in Iron

Effects of the Addition of Alloying Elements on Hydrogen Diffusion and Hydrogen Embrittlement in Martensitic Steel

“…Kushida et al have reported that the alloying of martensitic steel increases the concentration of absorbed hydrogen, which is inversely proportional to D, thereby promoting hydrogen embrittlement. [7][8][9] Therefore, a similar mechanism can be proposed for the investigated steels in this study. Nevertheless, the Mn-containing steels exhibited lower fracture stresses than other evaluated steels.…”

“…Moreover, Haruna et al analyzed the effects of the addition of Ni and Cr addition on D, 6) and the acquired D values were similar to those reported by Hagi. Furthermore, Omura et al also conducted similar investigations using various ferritic Fe-X alloys, 7) and suggested that the D values in Fe decreased upon alloy addition because of chemical interactions between hydrogen and solute atoms. Sawada et al explained these chemical interactions via density functional theory (DFT) calculations.…”

“…39) Therefore, depending on its concentration, Mo can be beneficial or detrimental. Another detrimental mechanism of Cr or Mo is an increase in the concentration of absorbed hydrogen due to a decrease in D [7][8][9] as discussed later.…”

“…12) and Fe-X alloys reported in a previous study. 7) Herein, the D values of the Fe-Mn alloy are the re-tested values. The D values of the Fe-X alloys depend on the index Cr + 0.5 Mo + 0.1 Mn + 0.1 Ni (at%), which is similar to that of the martensitic steels examined in this study (Fig.…”