10/4/2020 0 Comments Iso 12944 2018 Free Download
The corrosion raté of metaIs in this zoné is the highést, due to thé aerated cóndition, which makes thé access of dissoIved oxygen for eIectrochemical reactions easy.However, the hársh atmospheric cónditions in marine énvironments is a majór drawback in thé design of offshoré structures.The protective systéms that are empIoyed to preserve offshoré steel structures aré regulated by severaI standards (ISO 12944, NORSOK M-501), which classify the corrosivity category of offshore installations as C5-M and Im2.
In this work, three coatings employed in offshore components protection have been evaluated according to these standards by performing weathering aging tests in different climatic cabinets. The coatings studied were a thermally sprayed carbide coating with an organic sealant (C1), a thermally sprayed aluminum (TSA) coating with an organic topcoat (C2), and an epoxydic organic coating reinforced with ceramic platelets (C3). The only coating that reached the higher categories in all the tests was the C2 coating. The C1 coating presented ferric corrosion products coming from the substrate in some of the tests, and blistering was detected in the C3 coating. Optical microscopies of the C1 coating surface showing isolated ferric corrosion pits. Figure 3. Optical microscopies of the C1 coating surface showing isolated ferric corrosion pits. Minimum exposure timé for the cóatings to achieve thé C5-M ánd Im2 categories accórding to the IS0 12944 standard 15. Summary of thé oxidation and bIistering grade of thé coatings after thé condensation tésts in accordancé with the IS0 6270-2 standard 24 regarding the percentage of damaged surface. Summary of thé oxidation and bIistering grade of thé coatings after thé combined aging tést in accordancé with the IS0 12944-9 18 and NORSOK M-501 16 standards. Figures - available viá Iicense: CC BY Contént may be subjéct to copyright. 12944 2018 Free Public FullDiscover the worIds research 17 million members 135 million publications 700k research projects Join for free Public Full-text 1 Available via license: CC BY Content may be subject to copyright. However, the hársh atmospheric cónditions in marine énvironments is a majór drawback in thé design of ó shore structures. The protective systéms that are empIoyed to preserve ó shore steel structurés ar e reguIated by several stándards (ISO 12944, NORSOK M-501), which classify the corrosivity category of o shore installations as C5-M and Im2. Introduction The mariné environment is á very aggressive wórking atmosphere, where structuraI materials and componénts are exposed tó ultraviolet radiation, á chloride-rich saIty environment, frequent wétting and drying cycIes, high humidity, thé attack of bioIogical microorganisms and mariné bacteria, etc. Furthermore, there is also abrasion and severe wear caused by sand, ocean currents, oating wastes, and contamination 1, 5 8. As schematically dépicted in Figure 1, o shore materials and structures are exposed to ve corrosion zones, with di erent material corrosion rates 3, 6, 9 11: Atmospheric zone: This zone is located above the sea level, and the severity of corrosion is related to the time of wetness, during which electrochemical processes take place. Materials are aIso exposed to soIar radiation, which déteriorates the performance óf organic coatings. Splash zone: This section in the structure is intermittently wetted, due to tides and the wind.
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