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 MSA  Vol.7 No.10 , October 2016
Effect of Corrosion Inhibitor Used in Surface Treatment on the Anticorrosive Performance of an Epoxy Paint System
Abstract: The mechanism of corrosion is mainly sustained by an electrochemical process, in which anodic and cathodic reactions take place, keeping their kinetics alive by electrons and ions fluxes. Several specific conditions can accelerate corrosion processes. When studying anticorrosive coatings, one of them is the contamination of metallic surface by soluble salts prior to coating, leading to premature failure of the paint system due to corrosion between the metallic surface and the coating. So the surface preparation step prior to coating is a procedure of great importance to the coating anticorrosive performance. The aim of this step is to clean the surface by removing visible and non-visible contaminants. Usually, wet abrasive blasting methods are the most efficient ones to achieve the latter objective, because they may clean the surface, create a surface roughness and also remove the non-visible contaminants, as they use water as a media. On the other hand, evaporation of water after blasting may create flash rust and to avoid this, it is common to use corrosion inhibitors in the water of wet blasting methods. In this paper, the use of sodium tetraborate (borax) as a corrosion inhibitor in wet abrasive blasting is discussed. Electrochemical measurements and mass loss tests show that a borax content of 1% in a saline solution has the best inhibitory action over carbon steel and zinc surfaces, allowing postponing for the painting step some time. However, residual borax left on the surface generated blistering and corrosion under coating, during accelerated corrosion test in a humidity condensation chamber. Electrochemical impedance spectroscopy confirmed that borax accelerated the permeation of water through the coating, downgrading the anticorrosive performance of the paint system.
Cite this paper: Pontes, J. , Bendinelli, E. , da Costa Amorim, C. , de Sá, M. and Ordine, A. (2016) Effect of Corrosion Inhibitor Used in Surface Treatment on the Anticorrosive Performance of an Epoxy Paint System. Materials Sciences and Applications, 7, 593-609. doi: 10.4236/msa.2016.710049.
References

[1]   Jones, D.A. (1992) Principles and Prevention of Corrosion. Macmillan Publishing Company, New York.

[2]   Fuente, D., Chico, B. and Morcillo, M. (2006) The Effects of Soluble Salts at the Metal/Paint Interface: Advances in Knowledge. Portugaliae Electrochimica Acta, 24, 191-206.
http://dx.doi.org/10.4152/pea.200602191

[3]   Amorim, C.C., Café, Y.H.P., Sá, M.M. and Ordine, A.P. (2016) Efeito da Preparacao de Superfície de Aco Carbono na Formacao de Produtos de Corrosao sob Tinta Epóxi. Proceedings of the 6th International Corrosion Meeting, INTERCORR 2016, Búzios, 16-20 May 2016, 1-11.

[4]   Sá, M.M., Ordine, A.P., Oliveira, W.P. and Amorim, C.C. (2016) Avaliacao de Sistemas de Protecao Anticorrosiva para Manutencao de Estruturas Enterradas em Aco Galvanizado. Proceedings of the 6th International Corrosion Meeting, INTERCORR 2016, Búzios, 16-20 May 2016, 1-17.

[5]   Momber, A. (2012) Colour-Based Assessment of Atmospheric Corrosion Products, Namely of Flash Rust, on Steel. Materials and Corrosion, 63, 333-342.
http://dx.doi.org/10.1002/maco.201005831

[6]   Wienert, L.A. (1978) Resistance to Flash Rusting and Corrosion Undercutting of Water-Thinned Paint Films Containing Barium Metaborate. Anti-Corrosion Methods and Materials, 25, 10-14.
http://dx.doi.org/10.1108/eb007060

[7]   Kalendová, A. (2002) Methods for Testing and Evaluating the Flash Corrosion. Progress in Organic Coatings, 44, 201-209.
http://dx.doi.org/10.1016/S0300-9440(02)00014-0

[8]   SSPC-VIS 4/NACE VIS 7 (2014) Guide and Reference Photographs for Steel Surfaces Prepared by Waterjetting.

[9]   Wilson, L. (2012) The Paint Inspector’s Field Guide: For Protective Coating Inspection. TQC-USA Inc., Michigan.

[10]   Peters, H. (2004) Surface-Preparation Chemicals for Salt Decontamination or Flash Rust Inhibition. Materials Performance, 28, 28-30.

[11]   Rajagopalan, K.S., Venu, K. and Viswanathan, M. (1969) Activation of Passivated Steel in Borax Solution. Corrosion Science, 9, 169-177.
http://dx.doi.org/10.1016/S0010-938X(69)80027-2

[12]   Desai, M.N., Rana, S.S. and Gandhi, M.H. (1973) Corrosion Inhibitors for Zinc. Anti-Corrosion Methods and Materials, 20, 2-6.
http://dx.doi.org/10.1108/eb006939

[13]   Shreir, L.L. (1976) Corrosion Control. Newnes-Butterworths, London.

[14]   Eletrobras (2016) Eletrobras Standards for Anticorrosive Service Painting.
www.eletrobras.com.br/elb/normaseletrobrasdepinturaanticorrosiva

[15]   ISO 8407 Standard (2009) Corrosion of Metals and Alloys—Removal of Corrosion Products from Corrosion Test Specimens.

[16]   ASTM D 4585 Standard (2013) Standard Practice for Testing Water Resistance of Coatings Using Controlled Condensation.

[17]   ISO 4628-2 Standard (2003) Paints and Varnishes—Evaluation of Degradation of Paint Coatings—Designation of Intensity, Quantity and Size of Common Types of Defect, Part2: Designation of Degree of Blistering.

[18]   ASTM D 4541 Standard (2009) Standard Test Method for Pull-Off Strength of Coatings Using Portable Adhesion Testers.

 
 
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