Effects of Interstitial Nitrogen Atoms on Atomic Oxygen Adsorption on Fe (001) Surface from <i>Ab Initio</i> Calculations

Abstract

The effects of interstitial nitrogen atoms on the adsorption of atomic oxygen on fcc Fe (001) surface have been studied using ab initio density functional theory calculations to understand the initial stage of oxidation on nitrogenous austenitic stainless steel. It has been found out that the N atoms can improve the adsorption ability of the O atom at the hollow site on the surface, and thus promote the rapid passivation of nitrogenous austenitic stainless steel. This improvement is possibly because the Coulombic interactions between the O atom and the neighboring Fe and Cr atoms are enhanced due to the electron transfer from the Fe and Cr atoms to the N atoms.

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

“…Atomic oxygen makes it difficult for the surface to undergo more severe lattice distortions when the structure of several atomic layers near the surface is strengthened by nitrogen. In this progress, the enhanced internal structure will weaken the crystal field force on the surface electrons because the local charge is tightly bound inside, which is consistent with the previous literature [37]. According to Ye's report [37], the adsorption energy will increase along with the nitrogen content.…”

“…In this progress, the enhanced internal structure will weaken the crystal field force on the surface electrons because the local charge is tightly bound inside, which is consistent with the previous literature [37]. According to Ye's report [37], the adsorption energy will increase along with the nitrogen content. Therefore, the mechanism of increasing adsorption energy may be one of the reasons for rapid passivation and stabilization of the passivation film on nitrogen-containing austenitic stainless steel [40,41].…”

“…Strong charge transfer exists between austenite and atomic oxygen to form chemical bonds. The adsorption energy of atomic oxygen on pure γ-Fe is between the adsorption energy of the bridge site and the hollow site, as reported in Ye's work [37]. This situation is reasonable due to different parameter selection.…”

“…As a result, the system stability and adsorption energy increased. The phenomenon of nitrogen increasing adsorption energy has also been reported in the previous literature [37]. The mechanism of increasing adsorption energy may be one of the reasons for rapid passivation and stabilization of the passivation film on nitrogen-containing austenitic stainless steel [40,41].Therefore, the introduction of appropriate nitrogen atoms may contribute to the rapid passivation and stability of the surface passivation film, which is beneficial to the corrosion resistance.…”

“…It is well known that nitrogen alloying can significantly improve the pitting resistance of austenitic stainless steel despite its limited solubility. Ye et al [37] believed that the rapid passivation and stabilization mechanism of the nitrogen-containing surface of austenitic stainless steel [38][39][40][41] is closely related to the improvement of adsorption capacity caused by the presence of N atoms. These atoms can change the properties of the local structure and thus affect the adsorption of atomic oxygen.…”