Study of the initial stage of white rust formation on zinc single crystal by EIS, STM/AFM and SEM/EDS techniques

On the role of NO2− ions in passivity breakdown of Zn in deaerated neutral sodium nitrite solutions and the effect of some inorganic inhibitors

“…The characteristic feature of Zn dissolution in neutral media is that it involves consecutive and parallel paths coupled chemical and catalytic steps. It is generally accepted in the literature that, on the bare zinc, dissolution occurs via the adsorbed surface intermediate Zn(I) ads, in both aerated and de-aerated near neutral solutions [31][32][33][34]. Zn(I) ads may change electrochemically into Zn(II) ads .…”

“…The chemical consumption of Zn(II) ads leads to the formation of Zn 2+ ion. This step is influenced strongly by the presence of anions [31][32][33][34]. In a parallel path, Zn(II) ads can also be involved in a direct solid state formation of oxide [31]:…”

“…Under the prevailing conditions, it seems that the reactions occurring in the potential range of peak A can be associated to the formation of ZnO and Zn(NO 2 ) 2 as a result of adsorption of NO 2 − anions [35] on the metal surface and their participation in the chemical dissolution of the ZnO according to the overall reactions [25,31]:…”

Effect of Corrosion Product on the Electrochemical Behavior of Zn, Zn-Al and Al-Mg-Si Alloy Coated Steel

“…18,19 At pH value of 5.8 in 3 M NaCl or Na 2 SO 4 , according to Baugh, 19 the zinc electrode is coated with an oxide film, this film may affect both the anodic and the cathodic process but is not passivating. In addition Sziraki 20 reported that the dissolution-deposition exchange reaction of zinc alloy coating gives rise to an active surface in two ways. First, there are a large number of active sites for dissolution and, second, there are probably many oxide nuclei available for further grain growth.…”

Effects of residual white rust of inorganic zinc silicate primer on corrosion protection of epoxy-coated carbon steel

“…Water will continue to react with and progressively consume the zinc coating until the zinccoated substrate or moisture is removed from this environment. If zinc hydroxide or zinc oxide compounds are formed, the appearance of the zinc coating changes from a grey and smooth finish to a surface with white or grey powdery deposits known as white rust laid down in a porous and non-adherent manner [18]. Therefore, secondary blast cleaning is required to remove such white rust and contaminants before main coating process.…”