Echaniz_et_al-2019-Materials_and_Corrosion.pdf (2.51 MB)
Effect of seawater constituents on the performance of thermal spray aluminum in marine environments
conference contributionposted on 2019-06-14, 15:48 authored by Rosa G. Echaniz, Shiladitya Paul, Rob Thornton
Thermally sprayed coatings are often used to mitigate corrosion of offshore structures. They act as a physical barrier to the aggressive marine environment and as a sacrificial distributed anode for low carbon steel. In such environments, the severity of material degradation depends on many factors. The effect of temperature, exposure time or the presence of micro-organisms are the focus of many studies, for example, however, the effect of the different ions present in seawater remains largely unexplored. The chemical composition of the water changes considerably depending on the location; industrial, glacial, estuarine, and so forth. In addition, when thermal spray aluminum (TSA) protects steel in seawater, calcareous matter precipitates as a result of the cathodic polarization and subsequent localized increase in pH. Therefore, understanding how ions such as magnesium (II), calcium (II), or carbonates alter the coating properties in the marine environment is important. This paper reports the experimental work carried out with TSA-coated steel samples with defects to simulate mechanical damage or erosion of the coating. The combination of electrochemical tests and surface characterization provided evidence of the efficiency of the calcareous bilayer that forms on top of steel reducing the TSA degradation.
The 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. 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.
CitationMaterials and Corrosion, 2019, 70(6), pp. 996-1004
Author affiliation/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Engineering
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