Monitoring of a Zr-based conversion coating on galvanised steel and its performance against corrosion
- 27 August 2019
- journal article
- research article
- Published by SAGE Publications in Corrosion Engineering, Science and Technology: The International Journal of Corrosion Processes and Corrosion Control
- Vol. 54 (8) , 726-730
Abstract
New protective coatings with satisfactory performance and low impact are required by the surface treatment industry as effective Cr(VI)-free substitutes. Recently conversion coating systems containing Zr/Ti have shown great promise particularly for zinc finishes on steel and in this paper, we study the influence of bath conditions (e.g. pH and time) on conversion layers composed of a Zr-based film. The coating formation was studied by simultaneous monitoring of open circuit potential and surface pH using a novel cell design. Samples were subsequently characterised by electrochemical impedance spectroscopy in NaCl over a 24-hour period. The system demonstrates a correlation between pH of formation and corrosion resistance.Keywords
This publication has 23 references indexed in Scilit:
- Organosilane modified Zr-based conversion layer on Zn–Al alloy coated steel sheetsSurface and Coatings Technology, 2016
- Application of artificial neural network and adaptive neuro-fuzzy inference system to investigate corrosion rate of zirconium-based nano-ceramic layer on galvanized steel in 3.5% NaCl solutionJournal of Alloys and Compounds, 2015
- Corrosion resistance of chromium-free conversion coatings deposited on electrogalvanized steel from potassium hexafluorotitanate(IV) containing bathSurface and Coatings Technology, 2013
- The influence on immersion time of titanium conversion coatings on electrogalvanized steelThin Solid Films, 2010
- The molybdate–zinc conversion processCorrosion Science, 2009
- Synthesis and characterisation of surface gradient thin conversion films on zinc coated steelElectrochimica Acta, 2006
- The corrosion resistance of hot dip galvanised steel and AA2024-T3 pre-treated with bis-[triethoxysilylpropyl] tetrasulfide solutions doped with Ce(NO3)3Corrosion Science, 2006
- Influence of the conversion coating on the corrosion of galvanized reinforcing steelCement and Concrete Composites, 2006
- Molybdate conversion coatings on zinc surfacesJournal of Electroanalytical Chemistry, 2004
- Composition and corrosion behaviour of galvanised steel treated with rare-earth salts: the effect of the cationProgress in Organic Coatings, 2002