Pipelines for natural gas transmission may be subjected to plastic deformation by an outside force such as ground subsidence, ground liquefaction, hot bending, cold bending and mechanical damage. Plastic deformation affects the tensile properties and fracture toughness. Tensile test, Charpy impact test and S-N fatigue test were conducted on an API 5L X65 pipe to investigate the mechanical properties of pipeline subjected to plastic deformation during 3D hot bend. Tensile and fatigue test revealed that yield strength, tensile strength and fatigue strength of the extrados of the 3D bend were higher than those of the intrados of the 3D bend. However, Charpy impact energy of the intrados of the 3D bend was higher than that of the extrados of the 3D bend. There is no variation of strain at the crown according to the numerical analysis to the 3D hot bend. The equivalent strain up to 19 % shows in the side of the intrados of the 3D bend. The equivalent strain up to 15 % displays in the side of the extrados of the 3D bend.
|Number of pages||8|
|Publication status||Published - 2007 Aug 6|
|Event||2006 6th International Pipeline Conference, IPC 2006 - Calgary, AB, Canada|
Duration: 2006 Sept 25 → 2006 Sept 29
|Conference||2006 6th International Pipeline Conference, IPC 2006|
|Period||06/9/25 → 06/9/29|
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