It has been the purpose of this PhD program to determine whether current laboratory-based methods of investigating Atmospherically-Induced Stress Corrosion Cracking (AISCC) of austenitic Stainless Steels (SS) are adequate in modelling realistic corrosion processes within a marine aerosol environment. Results obtained throughout the study have sought to address three key aims. Mainly, to understand the nature and behaviour of primary marine aerosol containing organic matter present within oceanic surface waters, the interfacial interactions of such aerosol droplets deposited on to austenitic stainless steels and, ultimately, their impact upon AISCC processes. Based upon the work conducted during this research, several conclusions may be deduced. The presence of primary organic components within a sea-salt aerosol leads to a reduction in surface tension at the liquid-vapour interface; highlighting the surface-active nature of algal exudates. Surface-active constituents also have the potential to aggregate at the liquid-solid interface. The inclusion of exudates, therefore, has the potential to maintain an electrolytic environment on an austenitic steel substrate for an elongated time period under ambient conditions. Following subsequent evaporation, organically-enriched seawater droplets typically produce an organic surface film. The results of these interfacial studies have informed AISCC measurements using U-bend specimens, which demonstrate a correlation between cracking and droplet size. Furthermore, the limiting factor for AISCC may not be a function of deposition density as previously thought but rather of droplet surface area.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:634906 |
| Date | January 2015 |
| Creators | Gunther, Matthew |
| Publisher | University of Manchester |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://www.research.manchester.ac.uk/portal/en/theses/formulation-and-application-of-improved-marine-aerosol-proxies-for-atmospheric-corrosion-studies(058632b7-cec8-4a69-b50d-1f3b9ba24543).html |
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