Corrosion chemistry of galvanized steel in boric acid media


Corrosion chemistry of galvanized steel in boric acid media

Hoffmann, W.; Kryk, H.; Weiß, F.-P.

The corrosion of hot-dip galvanized steel in boric acid media has been investigated by different corrosion experiments at increased temperatures using galvanized steel samples. The related experiments are designed to aid the risk management of safety of nuclear power stations. The results of additional potentiodynamic measurements are used for the explanation of the corrosion mechanism by cathodic protection of steel. The surfaces of samples as well as the composition of solutions were examined by different analytical methods. No significant amounts of suspended solid corrosion products were detected up to 70 °C. However, on samples obtained at 90 °C, a solid corrosion product was formed which was identified as zinc borate. The fast corrosion of zinc in boric acid solution decreases with the reaction time as well as with increasing pH of the solution. After two days, a nearly constant level of zinc ion concentration reduces the further corrosion of zinc significantly. The local corrosion of galvanized steel is influenced by the double layer structure of the zinc coating.

  • Lecture (Conference)
    EUROCORR 2010, 13.-17.09.2010, Moscow, Russia
  • Contribution to proceedings
    EUROCORR 2010, 13.-17.09.2010, Moscow, Russia
    CD-ROM

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Publ.-Id: 14571