“…Once in the bulk, through various mechanisms, most prominently via hydrogen-induced decohesion or hydrogen-enhanced localized plasticity, the presence of hydrogen severely degrades the ductility and fracture toughness of the metals. While impacting a wide spectrum of infrastructures, HE is of particular importance in oil production and exploration fields since H 2 S and H 2 O are present in the drilling fluids, and H 2 S, in particular, is thought to be very aggressive to steels and Ni alloys. , Drilling environments contain up to several thousand parts per million of H 2 S, and their temperatures and pressure are usually 50–200 °C and up to 200 MPa, respectively. , Coating a thin oxide film onto the alloys could hinder some of the above-mentioned processes and therefore protect materials from HE. A limited amount of work , has been done so far to study the performance of oxide coatings for this purpose.…”