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Vol.11, No2, 2011, pp.89-96 |
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DAMAGE OF PIPELINES BY SANDBLASTING AND HYDROGEN Akram Alhussein 1,2, Julien Capelle 1, Joseph Gilgert 1, Saïd Hariri 3, Zitouni Azari 1 1) Laboratoire de Mécanique, Biomécanique, Polymères, Structures (LaBPS), Ecole Nationale d’Ingénieurs de Metz – Université Paul Verlaine de Metz, Metz, France 2) Laboratoire Universitaire des Sciences Appliquées de Cherbourg (LUSAC), ESIX Prod. Normandie, Cherbourg-Octeville, France 3) Département Technologie de, Polymères et Composites et Ingénierie Mécanique, Ecole des Mines de Douai, Douai Cedex, France |
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Abstract The mechanical behaviour evaluation of a pipeline notched under the impact of sand and hydrogen has been performed. Material damage is made by electrolytic hydrogen and by projecting corundum particles (aluminium oxide). The sandblasting and the hydrogen have little effect on the yield stress and ultimate strength. The pipe lifetime and elongation at fracture is clearly affected by hydrogen, which penetrates into the surface layers of the material and changes the local fracture mechanism. Despite the erosion of these layers under the sand impacting, their is mechanical property improvement: elongation at fracture and fatigue lifetime are shown. In order to justify these evolutions, a microstructural study is carried out. The observation of damage mode and distribution of residual stress under the notch tip show that the material hardening, the notch radius and the compressive stress play an important role in stabilizing the mechanical properties of the material. Keywords: pipeline, sandblasting erosion, electrolytic hydrogen, mechanical properties, residual stress analysis |
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full article (780 kB)
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