First‐Principles Study on Hydrogen Damage of Stainless Steel Passivation Film under Strain and Hydrogen Enrichment

As the first barrier of 316L stainless steel under hydrogen working conditions, the passivation film (Fe 2 O 3 /Cr 2 O 3 ) plays a crucial role in preventing hydrogen embrittlement of the stainless steel substrate. This study investigates hydrogen damage and corrosion mechanisms of the Fe 2 O 3 /Cr 2 O 3 interface in stainless steel passivation films under strain–hydrogen interaction. Compared with no strain effect, with the application of tensile stress or compressive strain, the hydrogen binding energy of Fe 2 O 3 /Cr 2 O 3 decreases, which alleviates the possibility of hydrogen damage to the passivation film. In order to better reveal the stability and corrosion resistance of the passivation film affected by hydrogen enrichment, an interface structure containing V Cr defects was constructed. The calculation results showed that compared to a single hydrogen atom, when six hydrogen atoms were enriched at the V Cr defect, the work function decreased by 47.5%, accompanied by an increase of 0.38 eV in charge transfer from hydrogen to Fe 2 O 3 /Cr 2 O 3 . These results clarify strain and hydrogen effects on passivation film stability, aiding in preventing hydrogen damage to the passivation film of stainless steel.