Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-27T23:02:22.879Z Has data issue: false hasContentIssue false
  • English
  • Français

Surface darkening phenomenon of Zn–Mg alloy coated steel exposed to aqueous environment at high temperature

Published online by Cambridge University Press:  09 December 2015

Sung Jin Kim ,
Young Jin Kwak ,
Tae Yeob Kim ,
Woo Sung Jung  and
Kyoo Young Kim
Sung Jin Kim*
Affiliation:
Graduate Institute of Ferrous Technology (GIFT), Pohang University of Science and Technology (POSTECH), Pohang 790-784, Republic of Korea
Young Jin Kwak
Affiliation:
Surface Treatment Research Group, POSCO Technical Research Center Kumho-dong, Gwangyang, Jeonnam 545-090, Republic of Korea
Tae Yeob Kim
Affiliation:
Surface Treatment Research Group, POSCO Technical Research Center Kumho-dong, Gwangyang, Jeonnam 545-090, Republic of Korea
Woo Sung Jung
Affiliation:
Surface Treatment Research Group, POSCO Technical Research Center Kumho-dong, Gwangyang, Jeonnam 545-090, Republic of Korea
Kyoo Young Kim
Affiliation:
Pohang University of Science and Technology (POSTECH), Pohang 790-784, Republic of Korea
*
a)Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

Steel coils coated with Zn–Mg alloy containing high Mg content develop dark rust when exposed to an extremely limited amount of aqueous environment. To understand the nature of the dark rust and its formation mechanism, the steel is evaluated by the immersion test and high temperature–humidity test followed by critical evaluation with transmission electron microscopy for cross-sectional observation, field-emission scanning electron microscopy for surface morphology observation, Auger electron spectroscopy and glow discharge spectroscopy for identification of chemical composition as a function of depth. The results indicate that the dark rust is formed by precipitation of Mg-based corrosion product on the outermost surface when the steel is exposed to aqueous environment at high temperature. This is due mainly to preferential dissolution of Mg phases by the galvanic action with MgZn2 and Mg2Zn11 composed of the coating layer, and easy precipitation of Mg2+ ion in a form of Mg(OH)2 in a limited volume of the condensed water film on the surface.

Keywords

coatingzincmagnesium
Type
Articles
Information
Journal of Materials Research , Volume 30 , Issue 23 , 14 December 2015 , pp. 3605 - 3615
Copyright
Copyright © Materials Research Society 2015 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Dutta, M., Halder, A.K., and Singh, S.B.: Morphology and properties of hot dip Zn–Mg and Zn–Mg–Al alloy coatings on steel sheet. Surf. Coat. Technol. 205, 2578 (2010).Google Scholar
Schuerz, S., Fleischanderl, M., Luckeneder, G.H., Preis, K., Haunschmied, T., Mori, G., and Kneissl, A.C.: Corrosion behaviour of Zn–Al–Mg coated steel sheet in sodium chloride-containing environment. Corros. Sci. 51, 2355 (2009).Google Scholar
Shih, H.C., Hsu, J.W., Sun, C.N., and Chung, S.C.: The lifetime assessment of hot-dip 5% Al–Zn coatings in chloride environments. Surf. Coat. Technol. 150, 70 (2002).Google Scholar
Watkins, K.G., Jones, R.D., and Beahan, P.G.: Electrochemical investigation of the corrosion rate of 55 aluminium-zinc alloy coated steel. Mater. Lett. 8, 26 (1989).Google Scholar
El-Mahdy, G.A., Nishikata, A., and Tsuru, T.: AC impedance study on corrosion of 55%Al–Zn alloy-coated steel under thin electrolyte layers. Corros. Sci. 42, 1509 (2000).Google Scholar
Palma, E., Puente, J.M., and Morcillo, M.: The atmospheric corrosion mechanism of 55%Al-Zn coating on steel. Corros. Sci. 40, 61 (1998).CrossRefGoogle Scholar
Hosking, N.C., Ström, M.A., Shipway, P.H., and Rudd, C.D.: Corrosion resistance of zinc–magnesium coated steel. Corros. Sci. 49, 3669 (2007).Google Scholar
Koll, T., Ullrich, K., Faderl, J., Hagler, J., and Spalek, A.: Properties and potential applications of novel ZnMg alloy coatings on steel sheet. In Galvatech'04. Proc. AIST, Chicago, IL, United States, 2004; p. 803.Google Scholar
Schwerdt, C., Riemer, M., Koehler, S., Schuhmacher, B., Steinhorst, M., and Zwick, A.: A study of the application related properties of novel Zn-Mg coated steel sheet produced in a continuous pilot line. In Galvatech'04. Proc. AIST, Chicago, IL, United States, 2004; p. 783.Google Scholar
Prosek, T., Nazarov, A., Bexell, U., Thierry, D., and Serak, J.: Corrosion mechanism of model zinc–magnesium alloys in atmospheric conditions. Corros. Sci. 50, 2216 (2008).Google Scholar
Volovitch, P., Allely, C., and Ogle, K.: Understanding corrosion via corrosion product characterization: I. Case study of the role of Mg alloying in Zn–Mg coating on steel. Corros. Sci. 51, 1251 (2009).CrossRefGoogle Scholar
Vlot, M., Bleeker, R., Maalman, T., and van Perlstein, E.: A new generation of hotdip galvanised products. In Galvanized Steel Sheet Forum. Proc. ILZRO and IZA, Dusseldorf, Germany, 2006.Google Scholar
Kazutoshi, S., Hiroshi, S., Masao, T., Hidetoshi, N., Koki, I., Junji, K., Shoji, M., Shingo, N., and Hirohiko, S.: Zn-Mg alloy vapor deposition plated metals of high corrosion resistance, as well as method of producing them. Patent 5135817, (1992).Google Scholar
Larché, N., Prosek, T., Nazarov, A., and Thierry, D.: Zn-Mg Automotives Steel Coatings. (Institut de la Corrosion technical report, 2008).Google Scholar
Kwak, Y.J., Kim, D.Y., Jung, W.S., Nam, K.H., Lee, D.Y., Hong, S.J., Kim, T.Y., Jung, Y.H., Eom, M.J., Choi, M.H., Kim, G.Y., Park, S.H., Lee, S.C., and Nam, Y.W.: A composition for forming the film for preventing the black stain of steel sheet, the steel sheet containing the film formed from the composition and method for forming the film. Korea Patent 10-2011-0027814, (2011).Google Scholar
Yasushi, F., Masanori, M., Hiroshi, T., Tadaaki, M., Kazushi, S., and Yasumi, A.: Steel sheet with Zn-Mg binary coating layer excellent in corrosion resistance and manufacturing method thereof. European Patent 00730045, (2000).Google Scholar
Samsonov, G.V.: The Oxide Handbook, 2nd ed. (Plenum, New York, 1982).CrossRefGoogle Scholar
Yanping, L., Zuyu, Q., and Yanming, J.: Investigation of black tarnished film on zinc plated surface. Corros. Sci. Prot. Technol. 12, 273 (2000).Google Scholar
Jones, D.A.: Principles and Prevention of Corrosion, 2nd ed. (Prentice Hall, New Jersey, 1996).Google Scholar
Wallinder, I.O., Augustsson, W.H.P., and Leygraf, C.: Characterization of black rust staining of unpassivated 55% Al-Zn alloy coatings, effect of temperature, pH and wet storage. Corros. Sci. 41, 2229 (1999).Google Scholar
Lindstrom, R., Johansson, L.G., Thompson, G.E., Skeldom, P., and Svensson, J.E.: Corrosion of magnesium in humid air. Corros. Sci. 46, 1141 (2004).Google Scholar
Ambrose, S., Gnanam, F.D., and Ramasamy, P.: Influence of additives on periodic crystallisation in Gel(I). Theory. Int. J. Chem. Sci. 92, 239 (1983).Google Scholar
Sontheimer, H. and Kuch, F.: Internal Corrosion of Water Distribution Systems, 2nd ed. (American Water Works Association Research Foundation, Colorado, 1996).Google Scholar
Chung, S.C., Lin, A.S., Chang, J.R., and Shih, H.C.: EXAFS study of atmospheric corrosion products on zinc at the initial stage. Corros. Sci. 42, 1599 (2000).Google Scholar
Liu, M., Zanna, S., Ardelean, H., Frateur, I., Schmutz, P., Song, G., Atrens, A., and Marcus, P.: A first quantitative XPS study of the surface films formed, by exposure to water, on Mg and on the Mg–Al intermetallics: Al3Mg2 and Mg17Al12 . Corros. Sci. 51, 1115 (2009).CrossRefGoogle Scholar