Effect of accumulated plastic strain on fatigue performance of super duplex steel used in umbilical tubes for oil production

The umbilical cable is today an important technology used to control equipment on the seabed in the production of offshore oil in deep and ultra-deep waters. The umbilical is composed of several components, including steel tube for transporting fluids for hydraulic control of equipment in the bed. S...

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Detalles Bibliográficos
Autores: Chaves , Antelmo Santos, Batista, Wilton Walter, Griza, Sandro, Cardoso, Raphael, Nascimento, Brenno Lima, Reis, Matheus Mariano da Silva, Santos, Renan Celestino Silva
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2022
País:Brasil
Institución:Universidade Federal de Itajubá (UNIFEI)
Repositorio:Research, Society and Development
Idioma:portugués
OAI Identifier:oai:ojs.pkp.sfu.ca:article/28614
Acceso en línea:https://rsdjournal.org/index.php/rsd/article/view/28614
Access Level:acceso abierto
Palabra clave:Acero inoxidable súper dúplex
Umbilical
APS
Enseñanza
Fatiga.
Aço inoxidável super duplex
Ensino
Fadiga.
Super duplex stainless steel
Teaching
Fatigue.
Descripción
Sumario:The umbilical cable is today an important technology used to control equipment on the seabed in the production of offshore oil in deep and ultra-deep waters. The umbilical is composed of several components, including steel tube for transporting fluids for hydraulic control of equipment in the bed. Such tubes are susceptible to fatigue during their life in umbilical operation. Fatigue strength is influenced by the accumulated plastic strain (APS) undergone by the tubes during the entire manufacturing process until installation/storage on spools. This present study investigated whether the way in which the APS is applied influences the fatigue strength of the tubes. Fatigue test specimens were machined from super duplex umbilical tube, which received 5% of APS by cyclic bending in two different ways: repeated bending and alternating bending. Microstructural and microhardness analyzes were performed on the specimens after fatigue fracture. No significant difference neither in microstructure, nor on the microhardness of the two groups of specimens was found after fatigue fracture. However, the group subjected to alternating plastic strain experienced lower fatigue strength. Therefore, the way in wich the tubes are deformed during manufacture and storage influences their fatigue performance.