Al-Khawarizmi Engineering Journal (Jan 2008)

Effect of Chloride Ions on the Corrosion Behavior of Al – Zn Alloy in NaOH Solution at Four Different Temperatures

  • Hind B. Al-Atrakchy,
  • Hanaa A. Al-Kaisy,
  • Rana A. Majed

Journal volume & issue
Vol. 4, no. 4
pp. 26 – 36

Abstract

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This research involves study effect of chloride ions in concentration range (0.01 – 0.50 mol.dm-3) on the corrosion behavior of Al-Zn alloy in basic media of 1x10-3 mol.dm-3 NaOH at pH=11 and four different temperatures in the range (298-313 K). Cathodic and anodic Tafel slopes (bc &ba) and transfer coefficients (αc & αa) were calculated and the results interprets according to the variation of the rate – determining steps. The results also indicate that the chloride ions are bonded chemically in the interface as an initial step of formation of different mixed oxohydroxy – and chloro complexes. Polarization resistance (Rp) is calculates and interprets the different polarization behavior because of addition of chloride ions to the basic media.

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