Evaluation of the role of surface pretreatments on the corrosion process. Correlation between conventional and electrochemical tests. Issue 12 (24th April 2017)

• Record Type: Journal Article
• Authors: Gimeno Pérez, M. J.; Molina Castellanos, J.; Izquierdo Escrig, R.; Puig Brugal, M.; García‐García, C.; Gracenea Zapiraín, J. J.; Suay Antón, J. J.
• Is Part Of: Materials and corrosion. Volume 68:Issue 12(2017)
• Page Start: 1302
• Page End: 1313
• Publication Date: 2017-04-24
• Subjects: amorphous phosphate -- corrosion tests -- microcrystalline phosphate -- powder coating -- sol‐gel; Materials -- Periodicals; Metals -- Periodicals; Corrosion and anti-corrosives -- Periodicals; 620.1122305
• DOI: 10.1002/maco.201609304
• Languages: English
• ISSNs: 0947-5117

Abstract

Abstract : The influence on the anticorrosion properties of three different pretreatments applied on steel panels, before being powder‐paint coated, is investigated both by conventional tests (cross cut, impact resistance, and neutral salt spray tests) and electrochemical tests (electrochemical impedance spectroscopy (EIS) and accelerated cyclic electrochemical technique (ACET)). Amorphous phosphate, microcrystalline phosphate, and a sol‐gel, based on 3‐aminopropyltriethoxysilane (APTES), were the different pretreatments that were analyzed. All of them were compared with a non‐pretreated coated carbon steel panel. The microcrystalline phosphate, followed by the sol‐gel surface treatments, showed the best system properties. These good results are attributed to P O 4 − 3 ions available at the interface, and to covalent bonds generated by the silicon network and the substrate surface, respectively. Abstract : It has been observed that phosphate molecules enhance the characteristics of coatings on steel. The more ordered the structure of the layer, the better improvement on properties. It has been confirmed that electrochemical tests lead to similar results than conventional measurements and give more accurate and deep information. But, in all cases, it is difficult differentiating close behaviors.