First Principles Study of Atomic Oxygen Adsorption on Austenitic Stainless Steels Surfaces: A Theoretical Study

The adsorption of atomic oxygen and surfaces is the starting point and key point to understand the oxidation process of stainless steel. Nowadays, numerous studies have focused on the metal composition of stainless steel, while the mechanism of non-metallic elements affecting atomic oxygen adsorption needs to be clarified. Here, adsorption of atomic oxygen on the surface of pure γ-Fe and H/N-containing austenitic stainless steels was investigated using first principles. We found that stable adsorption (>6 eV) can occur on pure γ-Fe and H/N-containing austenitic surfaces. In this process, the presence of hydrogen and nitrogen both enhance the adsorption of atomic oxygen, but their influence mechanisms are in opposition. Hydrogen enhances adsorption by breaking metal bonds near the surface, while nitrogen promotes adsorption by enhancing structural stability. The adsorption promotion of hydrogen (−6.7629 eV) is stronger than that of nitrogen (−6.6374 eV), but it can reduce the stability of the system. The introduction of appropriate nitrogen atoms may be beneficial to the improvement of corrosion resistance. This study provides valid data and a unique perspective on the erosion protection of atomic oxygen on austenitic surfaces.