Corrosion and protection of carbon steel in low enthalpy geothermal fluids. The case of SOUSAKI IN Greece

This experimental work is aimed at evaluating first, the effect of a solution simulating the geothermal fluid of the field in Sousaki, New Korinthia, on the corrosion of bare steel, and, second, the protective performance that certain combinations of organic coatings provide. This evaluation resulted from corrosion potential measurements, mass loss measurements, corrosion rate estimates by the Tafel method, and visual ranking of the degree of rusting and blistering. Six combinations of organic coatings were tested. Four of them consisted of water-based paints as primer, as well as intermediate and topcoat. Of the two remaining combinations, the first comprised a water-based primer, including dispersed tannin and a two-component epoxy resin topcoat, while the second consisted of a two-component acrylic primer, containing chromate pigments and the same epoxy resin topcoat as above. All coating combinations tested exhibited protective performance. The results of the water-based coatings were less satisfactory than those of the two combinations containing the epoxy resin topcoat. © 1997 CNR. Published by Elsevier Science Ltd. All rights reserved