Possible improvements in the action of some rust converters C.A. Barrero a,b , L.M. Ocampo b , C.E. Arroyave b, * a Solid State Group, Department of Physics, University of Antioquia, P.O. Box 1226, Medellin, Colombia b Corrosion and Protection Group, Department of Materials Engineering, University of Antioquia, P.O. Box 1226, Medellin, Colombia Received 8 September 1999; accepted 17 July 2000 Abstract The anticorrosive properties of 18 rust converters were investigated. The corrosion prod- ucts on pre-rusted mild steel samples and their mechanisms of reaction with the converters were studied. Accelerated corrosion tests were also performed. It was found that a mixture of tertbutyl and isopropyl alcohol facilitates penetration and adherence of the converters. Nev- ertheless, the converter does not reach the metal surface and the reactions are largely restricted to the outer layers. This circumstance, and the fact that anticorrosive properties are acceler- ated test-dependent, were considered as important reasons for the understanding of the contradictory results found with these products. Ó 2001 Elsevier Science Ltd. All rights re- served. Keywords: Rust converters; Tannic and phosphoric acids; Surface treatments; Corrosion products 1. Introduction Rust converters are chemical formulations that can be applied to corroded sur- faces causing their passivation and elimination of possible further attack after the application of a coating. However, it is not yet possible to ®nd on the market a really satisfactory product since reported results on the protection eciency are highly controversial. In fact, the diculty lies in ®nding the appropriate components, their optimal concentrations, the proper time of reaction, and the appropriate conditions www.elsevier.com/locate/corsci Corrosion Science 43 2001) 1003±1018 * Corresponding author. Tel.: +57-4-210-55-45; fax: +57-4-211-90-28. E-mail address: carroyav@udea.edu.co C.E. Arroyave). 0010-938X/01/$ - see front matter Ó 2001 Elsevier Science Ltd. All rights reserved. PII:S0010-938X00)00139-6