Silva, I.M.A. ; AOKI, I. V. ; COTTING, F. ; BENDINELLI, E. V. ; Sá, M. M. ; FONSECA, M. C. ; MARGARIT-MATTOS, I. C. P. .
Resumo: The purpose of this paper was to evaluate how different surface treatments of carbon steel influence the performance of a painting system with zinc rich primer. The surface treatments were applied to pre-corroded samples until degrees Sa3 as reference, St3 and SP11. Afterwards, the samples were painted with zinc rich primer, intermediate epoxy and polyurethane top coat. The specimens were subjected to cyclic corrosion test. The performance evaluation considered adhesion loss, blistering and corrosion advance around scribe. Electrochemical tests were carried out, including monitoring of open circuit potential and anodic polarization curves. The advantages of SP11 treatment compared to St3 were evidenced for the adherence and service-life of the painting system. However, consistent with previous results, a more important corrosion advance occurred around the risks in samples with SP11 treatment. Directly related to this greater advance, is the higher surface anodic activity detected by scanning vibrating electrode technique. Hypotheses justifying this behavior are heterogeneities in residual surface tension, as detected by X-ray measurements, and fouling with metallic material from the rotating brush.
