Evaluation of Zn- and Fe- rich organic coatings for corrosion protection and condensation performance on waste heat recovery surfaces. (May 2020)

• Record Type: Journal Article
• Authors: Pandis, Pavlos K.; Papaioannou, Stamatoula; Siaperas, Vasileios; Terzopoulos, Antypas; Stathopoulos, Vassilis N.
• Is Part Of: International Journal of thermofluids. Volume 3/4(2020)
• Publication Date: 2020-05
• Subjects: Corrosion -- Coatings -- Heat exchange -- Wetting -- Water collection -- Condensation; Thermodynamics -- Periodicals; Fluid mechanics -- Periodicals; 532.005
• DOI: 10.1016/j.ijft.2020.100025
• Languages: English
• ISSNs: 2666-2027

Abstract

Highlights: Epoxy-based zinc-containing organic coatings efficient on corrosion protection. Cost efficient market available coatings solutions for condensing economizer elements. Corrosion protection approach for structural parts or as touch up solutions. Coatings promoting drop wise condensation effect. Abstract: The corrosion protection performance of commercial organic coatings over Stainless Steel (304 L) was investigated in highly acidic media. Three coatings were applied by air spraying and subsequently evaluated for their performance against chemical corrosion by concentrated H2 SO4, HNO3, and HCl in terms of % mass loss. Open current potential (OCP) and potentiodynamic polarization (PD) measurements were performed. The water condensation properties of the coatings were monitored for their evaluation as potential protective coatings in condensing economizer applications. ZN691 coating exhibited better protection than ANORZINC and TROPIS versus time in contact with 40% of H2 SO4, HNO3 and 37% HCl. Electrochemical results confirmed the superior performance of ZN691 over ANORZINC and TROPIS with corrosion rates at 0.017, 0.098 and 0.097 mpy respectively. Condensation experiments for ZN691 showed a water collection rate of 1.487 ml m −2 h −1 at 40 °C and 100% RH. According to the results, the Zn rich epoxy-based coatings are promising for corrosion protection of condensing economizer elements.