The influence of liquid Pb–Bi on the anti-corrosion behavior of Fe3O4: a first-principles study

Abstract

In this work, the influence of Pb and Bi atoms on the anti-corrosion behavior of the oxide film (Fe₃O₄) formed on steel surface is investigated based on first-principles calculations. Through calculations of the formation energies, we find that Pb and Bi atoms can promote the formation of point defects, such as interstitial atoms and vacancies in Fe₃O₄. Besides, the effects of the concentration of Pb (or Bi) and pressure on the formation of these defects are also studied. Our results depict that a high density of Pb (or Bi) and compression pressure can promote the formation of defects in Fe₃O₄ significantly. Furthermore, the energy barriers for Pb and Bi atom migration in Fe₃O₄ are also estimated using the climbing image nudge elastic band (CI-NEB) method, which implies that Pb and Bi can diffuse more easily in Fe₃O₄ compared to Fe. Our results reveal the underlying mechanism of how Pb and Bi influence the anti-corrosion ability of oxide films in an accelerate driven system (ADS). It is instructive for improving the corrosion resistance of the oxide films in the ADS.