The Study Of Typical Corrosive Particles Adsorption On Chromium Doped Fe(110) Plane Based On Density Functional Theory

Due to the special property of chromium,it was often used to refine stainless steel to improve the corrosion resistance of the matrix by doping into steel or iron.In this paper,the composition of stainless steel is simply simulated by doping Cr atoms on pure iron surface,the anti-corrosion mechanism of Cr is discussed by comparing with pure iron structure.The interaction between Fe(110),Cr(110),intact Fe(110)Cr,defective Fe(110)Cr surfaces and three typical corrosive particles(H2O,Cl-,H+)were implemented,then we comparatively ensure the most stable adsorption sites of every particle on different structures after optimized by DMOl3 module.In addition,geometrical configuration,adsorption energy,bond length,population,electron transferring and density of states were also analyzed.The results show that the most stable adsorption sites of H2O,Cl-,H+ on Fe(110)and Cr(110)surfaces are top,top and hcp position,respectively.Comparing with the adsorption energy of a certain particle on the three surfaces,it can be obtained that Fe(110)Cr surface is the most stable,by the way,adsorption energies of particles on the same facet follow the decreasing order of H+>Cl->H2O.Comparing with the fresh surface,the partial bond lengths get longer and bond population occur smaller on surfaces after interacting with any particles,in addition,the influence of particles on the aspect of bond length in the same facet follow the order of H2O>Cl->H+,which indicates the particles are of different corrosive ability.After doping a Cr atom on Fe(110)surface,bond length of Fe-Fe all decreased,thus,the bond energy increased,which manifests that the doping of Cr on Fe substrate has the function of anti-corrosion.The resonance of PDOS occurred between partial atoms on crystal cross section and adsorbent fractional granules,the bonds of Fe(Cr)-O(H2O),Fe(Cr)-H(H+)and Fe(Cr)-Cl(Cl-)are formed,respectively,furthermore,these bonds follow the increasing order of bond energy.The electron orbital cloud scope of three kinds of particles abide by H2O>Cl->H+(on Fe surface),Cl->H+>H2O(on Cr-containing surface),the different sequence lies in the difference of metal radius and charge distribution on electron orbital influence.The DOS scope of three facets satisfy Cr(110)>Fe(110)Cr>Fe(110).Comparing with the intact Fe(110)Cr surface,the corrosive capability of adsorbent granules on defective Fe(110)Cr structure all increased,also the abilities abide by Cl->H+>H2O,which indicate that the surface of the defect is more prone to corrosion.