Influence of nanocrystallization on adsorption behavior of Cl^- on Fe20Cr Alloy in 0.1 mol/L Cl^- borate buffer solution

The effect of nanocrystallization on the adsorption of Cl^- on Fe20Cr alloy in [Cl^-]=0.1 mol/Lborate buffer solution was investigated by means of X-ray photoelectron spectrum (XPS) and calculations per the first-principles. The results show that the influence of Cr on Cl^- adsorption behavior could be described as the following two aspects: the one, in view of the calculation per the first-principles, is that the adsorption energy decrease with the increasing Cr content at the interface of passive film/alloy, which is conducive to the adsorption of Cl^-; the other is that the Cr enrichment may also facilitate the formation of passivation film, which inhibit the Cl^- adsorption. Nanocrystallization may enhance the diffusivity of Cr, which leads to the enrichment of Cr within the passive film as well as at the interface of passive film/alloy. Thus, nanocrystallization can inhibit the adsorption and the inward migration of Cl^-, and finally enhance the corrosion resistance of the alloy.