Investigation of Strain Ageing in FBE Coating of Pipeline Steels

Fusion-bonded epoxy (FBE) coating of line pipe usually induces an increase of yield strength (YS) and yield strength to tensile strength (Y/T) ratio, as well as a decrease of ductility and toughness. This phenomenon is known as strain ageing in pipeline steels. Strain ageing induced by coating of line pipe has become a big concern in pipeline industry because the increase of YS and Y/T as well as the decrease of ductility are believed to have adverse effects on pipeline hydrostatic test, cold field bending and fracture control.