Original scientific paper
https://doi.org/10.5599/jese.1130
Evaluation of paint systems on A36 steel through electrochemical techniques: Corrosion resistance of container tanks
Hugo Canahua Loza
; Universidad Nacional de San Agustín de Arequipa, Calle Santa Catalina 117, Arequipa 04001, Perú
Paul Huanca Zuñiga
; Universidad Nacional de San Agustín de Arequipa, Calle Santa Catalina 117, Arequipa 04001, Perú
Milagros Minga Adco
; Universidad Nacional de San Agustín de Arequipa, Calle Santa Catalina 117, Arequipa 04001, Perú
Carolyne Vizcarra
; Universidad Nacional de San Agustín de Arequipa, Calle Santa Catalina 117, Arequipa 04001, Perú
Leslie Canahua Sosa
; Universidad Nacional de San Agustín de Arequipa, Calle Santa Catalina 117, Arequipa 04001, Perú
María Escudero
; Department of Materials Engineering, Degradation and Durability National Center for Metallurgical Research (CENIM-CSIC), Gregorio del Amo 8, 28040 Madrid, Spain
Abstract
In this research work, the corrosion resistance of plate steel used in the construction of cylindrical container tanks of seawater was evaluated. These container tanks are usually used for fighting fires on the coast of the Arequipa-Peru region, where the shortage of drinking water is significant. The study was based on immersion tests of 2 × 2 cm square test plates in 3.5 wt.% NaCl solution. Five paint systems were studied, varying only in the primers: P1-860 (inorganic zinc silicate); P1-ZC (epoxy-zinchromate); P1-850 (organic rich in zinc); P1-600 (reinforced inorganic zinc) and P1-SP1000 (high solids epoxy-amine). All systems consisted of a primer coat, an epoxy middle coat and a polyurethane topcoat. To characterize the behaviour of each system, the electrochemical impedance spectroscopy (EIS) was mostly used. In addition, the scanning Kelvin probe (SKP) and scanning electrochemical microscopy (SECM) were used as local techniques. The first three paint systems (P1-860, P1-ZC and P1-850) showed an invariable value of impedance modulus up to 3360 h of immersion in NaCl. The last two paint systems (P1-600 and P1-SP1000) showed a decrease in impedance modulus by more than one order of magnitude. This research provides a clear contribution of results obtained by global electrochemical techniques such as EIS, establishing excellent tools for monitoring the performance of organic anticorrosive coatings.
Keywords
Plate steel; seawater storage tank; epoxy coating; electrochemical impedance spectroscopy
Hrčak ID:
279231
URI
Publication date:
13.6.2022.
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