摘要：For corrosion protection of steel pipeline, the external coatings are usually single, double or triple layered. These external coatings are composed of an epoxy primer, an adhesive and a thick layer of polyethylene or polypropylene. Internal stresses in these applications result in the disbondment of these coatings after only few years in service. This finite element study evaluated the internal stresses generated during the application process for different coating grades and thicknesses, and compared these values with the measured adhesion strength. The results showed that the thickness and grade of the coating affect internal stresses at the interface, as well as, produce an edge effect at the end of the pipeline which affects these stress-values. The axis-symmetric simulation and modelling of a section of a pipe during coating application process gave the stress distributions as a function of coating thickness for fusion bonded epoxy (FBE) and polypropylene (PP) layers. Also, it was discovered that the higher the polypropylene (PP) coating thickness with respect to the coating thickness of fusion bonded epoxy (FBE), the higher the stress in a 3-layer system. It is concluded that FBE coatings are best utilized as a monolithic corrosion protection coating ahead of a 3-layer system because of the lower stress regime during the manufacturing process.
关键词：Fusion Bonded Epoxy (FBE); Polyproplene (PP); Finite Element (FE)
