Evidence for an Unusual Temperature Dependence of the Atmospheric Corrosion of Zinc. Issue 14 (1st January 2016)

• Record Type: Journal Article
• Authors: Esmaily, M.; Mortazavi, N.; Svensson, J. E.; Johansson, L. G.
• Is Part Of: Journal of the Electrochemical Society. Volume 163:Issue 14(2016)
• Page Start: C864
• Page End: C872
• Publication Date: 2016-01-01
• Subjects: corrosion product composition -- corrosion rate -- temperature -- zinc; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0751614jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : The atmospheric corrosion behavior of zinc in the presence of NaCl has been investigated using well-controlled laboratory exposures in 95% RH air at ten different temperatures in the range −4 to 22°C. Results show that a critical temperature (∼ −0.5°C) exists in zinc corrosion above which the rate of corrosion is constant/independent of temperature, and, below which there is a positive correlation between temperature and corrosion rate. The corrosion products formed above and below −0.5°C are also entirely different. While simonkolleite, hydrozincite and zinc carbonate hydroxide are the main corrosion products at T ≥ −0.5°C, the same compounds are absent at T < −0.5°C. Instead, sodium zinc carbonate (Na2 Zn3 (CO3 )4 .3H2 O) is the dominant corrosion product at low temperature, together with Na2 ZnCl4 ·3H2 O and sweetite (Zn(OH)2 ). The results are interpreted in terms of two distinct corrosion modes prevailing at "high" and "low" temperature, respectively.