Kinetic Passivation Effect of Localized Differential Aeration on Brass
| Autor: | Aliaksandr S. Bandarenka, Arturo Estrada-Vargas, Balázs B. Berkes, Artjom Maljusch, Ricardo M. Souto, Volodymyr Kuznetsov, Wolfgang Schuhmann |
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| Rok vydání: | 2020 |
| Předmět: |
Materials science
Passivation Metallurgy Analytical chemistry 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Kinetic energy 01 natural sciences 0104 chemical sciences Gas phase Brass visual_art Technical university visual_art.visual_art_medium Aeration 0210 nano-technology |
| Zdroj: | ChemPlusChem. 81(1) |
| ISSN: | 2192-6506 |
| Popis: | The formation of a localized differential aeration cell on metals, susceptible to both anodic and cathodic corrosion, is a serious threat because of multiple degradation processes commencing with the passivation layer destruction. By using local electrochemical and X-ray dispersive techniques, it has been demonstrated that the differential aeration cell formed on high brass (α-brass, Cu65-Zn35) in the presence of 1H-benzotriazole or 5-methyl-1H-benzotriazole plays both corrosion-inhibiting and accelerating roles, depending on the inhibitor exposure time. Alternating-current scanning electrochemical microscopy was used to image local electrochemical activity, whereas energy-dispersive X-ray spectroscopy provided evidence for the mechanism of the observed phenomena. Short-term exposure to the inhibitor (5 min) promotes the formation of a passivation layer in the waterline region. In contrast, after prolonged exposure (45 min), a deficient passivation layer develops for both inhibitors. An excess of zinc(II)-inhibitor complexes in the passivation layer is accountable for the corrosion resistance of the region with high differential aeration. Rapid dezincification and local alkalinization facilitate the initial rapid formation of a passivation layer in the area under differential aeration to preserve its composition upon further modification. |
| Databáze: | OpenAIRE |
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