Elucidating the hydrogen-entry-obstruction mechanism of a newly developed aluminum-based coating in high-pressure gaseous hydrogen

Doping α-Al2O3 to reduce its hydrogen permeability: Thermodynamic assessment of hydrogen defects and solubility from first principles

“…The past few years have witnessed a growing interest in the study of hydrogen in oxides. One area of key focus has been on understanding the factors influencing hydrogen permeability in barrier oxides like Al2O3 [1][2][3][4][5]. Hydrogen permeation barriers (HPBs) are needed for high temperature applications such as that in nuclear reactors to prevent tritium escape into the environment [6], as well as for room temperature applications such as preventing embrittlement of steels used in hydrogen storage and transport infrastructure [7].…”

Investigation of hydrogen transport behavior of various low-alloy steels with high-pressure hydrogen gas

“…Different from low-alloy steel, the value of D for g-stainless steel at RT was estimated to be approximately 1 Â 10 À16 m 2 /s for both palladium-sputtered and non-sputtered specimens, though the g-stainless steel possesses a native oxide layer of a few nanometers thickness, similar to that in low-alloy steel [31]. To interpret the experimental results, the FEM analysis taking account of the surface reaction of hydrogen was performed for the conditions D ¼ 1.0 Â 10 À16 m 2 /s and k ¼ 1.0 Â 10 À8 m/s.…”

“…Identical experimental results were obtained when the surfaces were finished with #600 emery paper. Based on our previous study [31], a native oxide layer with a few nanometers thickness is formed on the surface and surface reactions of hydrogen, such as dissociation and recombination, may affects the measured hydrogen diffusivity. To examine effects of such surface reactions on the entry and exit of hydrogen gas, a palladium layer approximately 10 nm thick was deposited by ion sputtering on the surface of some of the specimens.…”

“…To examine effects of such surface reactions on the entry and exit of hydrogen gas, a palladium layer approximately 10 nm thick was deposited by ion sputtering on the surface of some of the specimens. It is noted that the native oxide layer remains at the subsurface of the palladium-sputtered specimens, whereas the surface is covered with the palladium layer [31]. All specimens were exposed to high-pressure hydrogen gas at 100 MPa and a temperature of RT, 50 C, or 85 C for around 250 h. To prevent unwanted hydrogen desorption, the treated samples were kept under liquid nitrogen until their hydrogen content was measured.…”

Effect of Gas Pressure on Hydrogen Environment Embrittlement of Carbon Steel A106 in Carbon Monoxide Mixed Hydrogen Gas

“…[1] Coleman et al reported that a Zn-Ni alloy coating on Fe surface suppressed hydrogen permeation into the material during cathodic charging. [2] Furthermore, Yamabe et al developed an aluminium-based coating that shows a high resistance against hydrogen uptake into the material in a 100 MPa H 2 environment at 543 K. [3] However, a gas impurity contained in H 2 is well recognized to affect the HEE if the impurity has an interaction with the Fe surface. For instance, O 2 and CO have been shown to mitigate susceptibility to HEE, [4][5][6][7][8][9][10][11] while H 2 S enhances HEE susceptibility.…”