Structural characterization of iron oxide grown on 18% Ni-Co-Mo-Ti ferrous base alloy aged under superheated steam atmosphere

18% Ni-Co-Mo-Ti ferrous base alloys are special materials, widely used in the industry of isotopic enrichment after specific annealing and aging thermal treatment. The desirable high mechanical properties can then be attained by adequate heat treatment, answering structural materials specifications required defense applications aerospace nuclear engineering. For instance, enrichment, rocket engine envelope application, when associated with temperature chemical residues like acidic solutions, induce corrosion hydrogen embrittlement martensitic microstructure. In order to limit these phenomena, adherent protective layers iron oxides grown on material’s surface performing treatment an atmosphere. Due its application strategic areas, characterization oxide maraging steels is importance as well understanding their growth kinetics. this purpose, several techniques, such optical microscopy (OM), scanning electron (SEM), glow discharge emission spectroscopy (GDOES), microabrasive wear testing, hardness, grazing incidence X-ray diffraction (GIXRD), photoelectron (XPS), have been performed for films formed vapor exposed at 510℃. layer consists two sub-layers composed magnetite ( $${Fe}_{3}{O}_{4}$$ ) external hematite $${Fe}_{2}{O}_{3}$$ ). A thick interface between bulk enriched Ti Mo, whereas analyses deep material show area Ni Co.