Chinese Journal of Applied Chemistry ›› 2010, Vol. 27 ›› Issue (07): 836-841.DOI: 10.3724/SP.J.1095.2010.90692

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Synergistic Inhibition Effect of Rare Earth Ce4+ and Vanillin on the Corrosion of Cold Rolled Steel in H3PO4 Media

LI Xiang-Hong1*, DENG Shu-Duan2, FU Hui1, MU Guan-Nan3   

  1. (1.Department of Fundamental Courses,Southwest Forestry University,Kunming 650224;
    2.Faculty of Wood Science and Decoration Engineering,Southwest Forestry University,Kunming;
    3.Department of Chemistry,Yunnan University,Kunming)
  • Received:2009-10-20 Revised:2009-12-29 Published:2010-07-10 Online:2010-07-10

Abstract:

The synergistic inhibition effect of rare earth Ce4+ and vanillin(4-hydroxy-3-methoxybenzaldehyde) on the corrosion of cold rolled steel(CRS) in 3.0 mol/L H3PO4 solution was studied by mass loss, potentiodynamic polarization and UV-Vis spectrophotometry(UV-Vis). The present study reveals that vanillin exhibits a moderate inhibitive effect on the corrosion of CRS. The inhibition efficiency(IE) increases with the concentration increase, and the maximum IE is 66%. The adsorption of vanillin on the CRS surface obeys Freundlich adsorption isotherm equation. Ce4+ shows a poor inhibition performance and the maximum IE is not more than 20%. However, incorporation of rare earth Ce4+ with vanillin significantly improves the inhibition performance and produces a synergistic inhibition effect. The maximum IE is as high as 90%. Ce4+ and vanillin form a new complex, which acts as a mixed-type inhibitor.

Key words: phosphoric acid, cold rolled steel, vanillin, rare earth, Ce4+, synergistic inhibition effect

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