铜锑钢耐Cl原子腐蚀性能的第一性原理研究

First-Principles Study on Corrosion Resistance to Cl Atom of Copper-Antimony Steel

采用基于密度泛函理论的第一性原理方法和具有三维周期性边界条件的超胞模型,结合VASPsol隐式溶剂模型,计算了Cl原子在α-Fe(100)纯表面及铜锑掺杂表面的吸附能、功函数、bader电荷等,分析了Sb和Cu掺杂对体系表面Cl原子吸附行为的影响。结果表明:Sb和Cu在Fe(100)表面掺杂后降低了Cl原子的表面吸附倾向,抑制了Cl原子和体系表面Fe的电荷交换,阻碍了Cl原子和Fe之间反应产物的生成;在含氮环境中,Sb附近区域易发生电化学腐蚀,使得Sb、Cu进入溶液,两者原子的协同作用促进Cu和Cl原子反应形成含铜氯化物覆盖于基体表面,且该趋势随着Cl原子覆盖度的增大而增强。

The first principle method based on density functional theory and the supercell model with three-dimensional periodic boundary conditions,combined with VASPsol implicit solvation model,were used to calculate the adsorption energy,work function and bader charge of Cl atom onα-Fe pure surface and copper-antimony doped surface,and the effect of Sb and Cu doping on the adsorption behavior of Cl atom on the system surface was analyzed.The results showed that the doping of Sb and Cu on the surface of Fe(100)weakened the tendency of Cl atoms adsorption on the surface,inhibited the charge exchange between Cl atoms and Fe on the system surface,and hindered the formation of reaction products between Cl atom and Fe.In the chlotide environment,electrochemical corrosion was prone to occur in the area near Sb,which made Sb and Cu enter the solution,and the synergistic action of the two atoms promoted the reaction of Cu and Cl atom to form Cu chloride covering the surface of the matrix,and this trend increased with the increase in the coverage of Cl atom.