Long-Term Atmospheric Corrosion of Hot-Dip Galvanized Steel and Zn-Al Coated Steel

Abstract

Hot dip galvanized steel and zinc alloyed coated steel such as ZnAl are widely used in the building industry. However, despite large efforts made to study the corrosion products formed on zinc under atmospheric weathering conditions (see for instance reference 1 and 2), very few data exist on HDG and zinc alloyed coated steel [5]. This work is a part of a larger research program were steel with different zinc coatings are exposed on a worldwide basis on well characterized exposure sites in Europe, Asia and North America, see Table 1. Corrosion rates of hot dip galvanized steel and zinc aluminum coated steel (e.g. Zn5%Al and Zn 55% Al) were determined after 1, 2, 4 and 6 years of exposure under different climatic conditions. The formation and development of corrosion products was followed by detailed analysis of samples exposed 0.5, 1, 2, 4 and 6 years using XRD, FTIR-spectroscopy and SEM-EDS. The data are discussed in view of current knowledge in the atmospheric corrosion of zinc, HDG and Zn-Al coated steel materials [1-6] Table 1. Test sites in the exposure program Code Name Country Distance to Sea(m) A Brest France <5 B Bohus-Malmön (I) Sweden <5 C Bohus-Malmön (II) Sweden 300 D Ijmuiden Netherlands 2600 E Cadiz Spain 750 F Jiangjin China ̴900 km G Ostrawa Czech Republic ̴500 km H Dubai UAE 2000 I Daytona Beach USA 100 J Quindao China 10 K Wanning China 100 L Bangkok Thailand 35 km M Sattahip Thailand 10 N Singapore SIngapore 10 References 1-I. Odnevall, C. Leygraf, Corros. Sci. 34 (1993) 1213–1229. 2- I. Odnevall, C. Leygraf, Corros. Sci. 36 (1994) 1551–1567. 3- N. Le Bozec, D. Thierry, M. Rohwerder, Dan Persson, G. Luckeneder and L. Luxem, Effect of CO2 on the atmospheric corrosion of ZnMgAl coated steel, Corrosion Science, 74, pp 379-386, 2013 4- E. Diller, B. Lescop, S. Rioual, G Nguyen, D. Thierry and B. Rouvello, Initial formation of corrosion products on pure zinc and MgZn2 examined by XPS: Corrosion Science 79, pp 83-88, 2014. 5- D. Persson, N. Le Bozec, T. Prosek, D. Thierry, G. Luckenader , Corrosion Science Vol 90, pp 276-283, 2015. 6- D. Persson, D. Thierry, N. Le Bozec: Corrosion products formation on Zn55Al upon exposure in marine atmosphere, Corrosion Science, 720, 2011.