This work presents the effect of a "green" rust converter applied on surface of a carbon steel sample immersed in seawater using an electrochemical noise (EN) technique. Working electrodes was made of carbon steel (with rust, with rust and converter and bare samples) and the saturated calomel electrode was used as reference electrode. The highest corrosion rate (CR) was obtained in the bare samples (samples without rust and converter) and the lowest CR was obtained in the samples with rust and converter, this behavior was attributed to the magnetite and iron tanates. A stable behavior was observed in samples with rust and converter during all exposure time. The localization index for the rusted sample and rusted sample with converter showed a mix process while the bare sample showed a general corrosion. It is important to point out that in all optical micrographs was possible to observe a localized corrosion type.

Tannic extract of the Mimosa Tenuiflora was assessed as a rust converter using Electrochemical Impedance Spectroscopy (EIS) and Linear Polarization Resistance (LPR) techniques. The tannic extract was applied on pre-corroded AISI 1018 steel plates before a commercial epoxy coating. Four different specimens were prepared and submerged in two solutions, 0.51 M NaCl and 0.1 M Na 2 SO 4 . All systems were inspected for 40 days in search of changes in the coatings. The exposure time and the reaction time of the rust converter are important factors to obtain good performance.