Interfacial corrosion behavior between O atoms and alloy elements at iron-liquid LBE interface by first-principles molecular dynamics

Abstract

The interfacial corrosion behavior between LBE adding O atoms and Fe substrate surface containing alloy elements (Cr, Ni, Al, Si) has been studied by first-principles molecular dynamics simulations. Theoretical calculations show that the O atoms in liquid LBE could form the protective oxide layer with the alloy elements (Cr, Al, Si) on the Fe substrate surface at the iron-liquid LBE interface, in which slows down the corrosion process. The estimated mean effective potential energy path suggests that breaking the OSi bond requires the highest energy barrier of 0.61 eV among the doped elements. Besides, the diffusion coefficient shows that Si atom has the lowest value of 0.277 × 10−5 cm2/s, which indicated that adding doped-Si atoms can effectively slow down the corrosion process of the steel. In addition, the diffusion coefficient of Pb, Bi and O atoms in this work is much lower compared with the previous work, indicating that the oxide layer formed at the iron-liquid LBE interface can effectively improve the corrosion resistance of the steel. In a word, this work is instructive for a deeper understanding of corrosion mechanism and provides valuable information for the performance evaluation and material design of the steel under reactor conditions.