Long-term barrier effects of Cr (III)- and Cr (VI)- treated zinc surfaces on metal release
2008 (English)In: Int. Corros. Congr.: Corros. Control Serv. Soc., 2008, 2573-2583 p.Conference paper (Refereed)
The recently implemented legislation regarding handling of chemicals in the European Union, and a generally increased environmental awareness in the society have generated a need to quantify diffuse metal flows from metallic product surfaces. The use of Cr(VI) in surface treatments on external constructions (e.g. on galvanized steel) is questioned and powerfully restrained by this legislation. Therefore, environmentally friendly alternatives based on e.g. Cr(III) are now available on the market. In this study, corrosion-induced changes in barrier effects in terms of release of zinc and chromium and changes in surface properties with time were investigated for bare zinc sheet and continuously galvanized steel with surface treatments based on Cr(III) or Cr(VI) in long-term field exposures at an urban (Stockholm, Sweden) and a marine site (Brest, France). Essential key information is generated to assess potential adverse environmental effects caused by the use of these surface treatments. Preliminary results from the urban site show the Cr(VI)-based surface treatments, at least initially, to have a higher barrier effect for zinc release compared to the Cr(III)-based surface treatment. Both surfaces resulted in significantly lower release rates of zinc compared to bare zinc sheet. Chromium was released from both surface treatments (Cr(VI)≫Cr(III)) at significantly lower rates compared to zinc, whereby the rates decreased with time.
Place, publisher, year, edition, pages
2008. 2573-2583 p.
, 17th International Corrosion Congress 2008: Corrosion Control in the Service of Society, 4
Atmospheric corrosion, Cr(III)- and Cr(VI)- surface treatments, Runoff rates, Zinc, Barrier effects, Environmental awareness, Environmentally friendly alternatives, European union, Field exposure, Galvanized steels, Metal flow, Metal release, Product surface, Release rate, Stockholm, Sweden, Urban site, Zinc sheets, Chromium compounds, Corrosion prevention, Galvanizing, Surface properties, Chromium
IdentifiersURN: urn:nbn:se:kth:diva-153338ScopusID: 2-s2.0-84864990383ISBN: 9781615674251OAI: oai:DiVA.org:kth-153338DiVA: diva2:755230
17th International Corrosion Congress 2008: Corrosion Control in the Service of Society, 6-10 October 2008, Las Vegas, NV, USA
QC 201410142014-10-142014-10-032014-10-14Bibliographically approved