Hydrogen Embrittlement Resistance andHydrogen Barrier Mechanism of Atomically Doped Cr₂O₃ Coatings on Heat-Resistant Steel

To address the performance degradation of heat-resistant steel caused by hydrogen embrittlement in high-temperature and high-pressure hydrogen environments,this study proposes an atomically stabilized doped Cr₂ O₃ composite anti-hydrogen embrittlement coating and elucidates the mechanism underlying its enhanced hydrogen embrittlement resistance and hydrogen barrier effect using first-principles calculations.First,a Cr₂ O₃ bulk structure is constructed and a Cr atom is then substituted with Al,Mn,Ni,Ti,Y,or Si atoms.Subsequently,the effects of different atomic dopants on the adsorption energy of H atoms at the surface and subsurface,the electronic properties of H atom adsorption on the surface,and the diffusion behavior of H atoms on the hydrogen barrier performance of Cr2O3 films are investigated.Simulation results demonstrate that doping with Al,Ti,and Si atoms increases the adsorption energy of H atoms,making surface adsorption more difficult.The electronegativity of Al,Mn,Ti,and Y dopants is lower than that of Cr,weakening the adsorption energy of H atoms at the surface A-site.Additionally,doping with Al,Mn,Ti,and Si atoms increases the diffusion energy barrier for H atoms migrating from the surface to the subsurface,thereby hindering hydrogen penetration.This study reveals the mechanism by which dopant atoms enhance the hydrogen embrittlement resistance of Cr₂O₃ coatings and proposes an atomic doping strategy to improve hydrogen barrier performance.