Abstract
Corrosion protection of structures operating in seawater is usually provided by cathodic protection (CP) by sacrificial anodes, often in conjunction with protective organic coatings. However, these methods have some limitations. Organic coatings, when used without CP, can provide protection to steel only when intact and anodes not only significantly increase the overall mass of the structure, but also have to be replaced periodically. An alternative corrosion mitigation method is the application of thermally sprayed metallic coatings, such as Al, Zn and ZnAl, which work as a barrier to corrosive environments when intact, and as an evenly distributed sacrificial anode when damaged. In this work, the behavior of arc-sprayed ZnAl- and Al-coatings was investigated under two conditions - (i) full immersion in artificial seawater (ASTM D1141), and (ii) under droplets of artificial seawater. The first to simulate the immersed zone and the second to simulate above-surface splash zone conditions. The effectiveness of the coatings was evaluated using electrochemical techniques (OCP monitoring, dynamic polarization and LPR). Raman spectroscopy and SEM/EDX were employed to analyze corrosion products.
| Original language | English |
|---|---|
| Article number | 12808 |
| Journal | NACE - International Corrosion Conference Series |
| Volume | 2019-March |
| Publication status | Published - 2019 |
| Event | Corrosion Conference and Expo 2019 - Nashville, United States Duration: 24 Mar 2019 → 28 Mar 2019 |
Bibliographical note
Funding Information:Authors gratefully acknowledge financial support from the Centre for Doctoral Training in Innovative Metal Processing (IMPaCT) funded by the UK Engineering and Physical Sciences Research Council (EPSRC), grant reference EP/L016206/1.
Funding Information:
This publication was made possible by the sponsorship and support of Lloyd’s Register Foundation, a charitable foundation helping to protect life and property by supporting engineering-related education, public engagement and the application of research. The work was enabled through, and undertaken at, the National Structural Integrity Research Centre (NSIRC), a postgraduate engineering facility for industry-led research into structural integrity established and managed by TWI through a network of both national and international Universities.
Publisher Copyright:
© 2019 by NACE International.
Keywords
- Cathodic protection
- Corrosion protection
- Metallic coatings
- Thermally sprayed coatings
- TSA
- Zn-Al
ASJC Scopus subject areas
- General Chemistry
- General Chemical Engineering
- General Materials Science