Formation of galvanic cells and localized corrosion of zinc and zinc alloys under atmospheric conditions
2017 (English)In: Corrosion, ISSN 0010-9312, E-ISSN 1938-159X, Vol. 73, no 1, p. 77-86Article in journal (Refereed) Published
Abstract [en]
Atmospheric corrosion of Zn and Zn alloys with local NaCl contaminations was studied in situ by scanning Kelvin probe. The corrosion process was accompanied by the formation of clearly separated anodic and cathodic locations and local galvanic cells on the surface. The corrosion activity correlated to variations in Volta potential during air to nitrogen transients. The effect of dielectric and semiconducting solids on the efficiency of cathodic reaction on zinc was investigated. The rate of oxygen reduction was high on semiconducting ZnO films with defective structure, as they are effective donors of electrons. Mg, Ti, Cr, and Al were alloyed to zinc to modify the composition of surface oxide films. The addition of Mg provided the most effective corrosion inhibition, blocking completely the spreading of the cathodic area from NaCl contamination. The other elements had minor influence, but might be applied for further improvement of the Zn-Mg system. The effect of Mg is believed to be connected to semiconducting properties of the formed surface oxide film.
Place, publisher, year, edition, pages
National Assoc. of Corrosion Engineers International , 2017. Vol. 73, no 1, p. 77-86
Keywords [en]
Atmospheric corrosion, Galvanic cell, Localized corrosion, Scanning Kelvin probe, Zinc alloys, Aluminum alloys, Binary alloys, Electrochemical cells, Electrolytic reduction, Galvanic corrosion, II-VI semiconductors, Magnesium, Magnetic semiconductors, Oxide films, Probes, Semiconducting films, Sodium alloys, Sodium chloride, Titanium oxides, Wide band gap semiconductors, Zinc oxide, Atmospheric conditions, Corrosion inhibition, Defective structures, Galvanic cells, Scanning Kelvin probes, Semi-conducting property, Semiconducting solids, Surface oxide films
National Category
Natural Sciences
Identifiers
URN: urn:nbn:se:ri:diva-40508DOI: 10.5006/2139Scopus ID: 2-s2.0-85031698445OAI: oai:DiVA.org:ri-40508DiVA, id: diva2:1359861
2019-10-102019-10-102023-05-16Bibliographically approved