Dissecting Coating Disbondments

016436092010Final Report, Rev 1PDFTech ReportReport No./DNV Reg No.: ENAUS 811 Brossia (101131) Rev 1DTPH56-06-T-000018Bond strength (Materials)CoatingsCorrosionFailureField studiesLaboratory testsPipelinesResearch Hubmaintenance and preservationpipelinesUnited StatesDet Norske Veritas, IncorporatedBrossia, SeanDet Norske Veritas, IncorporatedUnited States. Dept. of Transportation. Pipeline and Hazardous Materials Safety AdministrationUS Transportation CollectionCoatings are the primary means for imparting corrosion protection to gas and liquid pipelines. Though cathodic protection is also often applied, if no coating was present the demand for supplied current to effectively catholically protect the pipe would be cost-prohibitive. Because coatings are the main line of defense, understanding how they disbond from the pipe and lead to defects and flaws which in turn could result in subsequent corrosion is important. The objective of this project was to identify the conditions promoting coating disbondment during in-service exposure. A set of variables including coating chemistry, surface chemistry, surface roughness, anchor pattern, coating underside chemistry, and optical analysis was investigated and the critical parameters leading to disbondment evaluated. Developing a better understanding of the coating disbondment process, especially concerning the initial stages of coating degradation, gained during the project will serve as a stepping stone for developing a field-based methodology to predict long-term coating performance and to identify the onset of disbondment