A finite element based model for prediction of corrosion defect growth on pipelines. (June 2017)

• Record Type: Journal Article
• Authors: Xu, Luyao; Cheng, Y. Frank
• Is Part Of: International journal of pressure vessels and piping. Volume 153(2017)
• Page Start: 70
• Page End: 79
• Publication Date: 2017-06
• Subjects: Pipelines -- Corrosion defect -- Long-term growth -- Finite element model -- Mechano-electrochemical interaction; Pressure vessels -- Periodicals; Pipe -- Periodicals; Récipients sous pression -- Périodiques; Tuyaux -- Périodiques; Pipe; Pressure vessels; Periodicals; 681.76041
• DOI: 10.1016/j.ijpvp.2017.05.002
• Languages: English
• ISSNs: 0308-0161

Abstract

Abstract: Growth of corrosion defects has been identified as the primary mechanism resulting in pipeline perforation and leaking. In this work, a finite element model was developed to simulate and predict the time-dependent growth of corrosion defects on pipelines in a near-neutral pH bicarbonate solution trapped under disbonded coating. The synergism of stress and local corrosion reaction was determined quantitatively. It is demonstrated that a mechano-electrochemical effect developed at the defect is critical to growth of the defect, resulting in formation of a crack-like flaw at the defect center. The time dependence of the local stress and corrosion current density at the defect is featured with three stages, i.e., a linear increase of local elastic stress and the negligible corrosion enhancement under the testing condition, a slow increase of both local stress and corrosion current density under mild plastic deformation, and a rapid increase of local stress and corrosion current density under a high plastic deformation. Highlights: Developed a finite element model to predict growth of corrosion defects on pipelines. Determined quantitatively the synergism of stress and corrosion on defect growth. Proposed the mechano-electrochemical effect for pipeline defect assessment.