Etude de l'effet de l'usure et du grippage sur l'étanchéité des portées métalliques // Investigation of wear and seizure effects on the sealing performances of metallic connection

La société Vallourec est leader mondial des solutions tubulaires premium destinées principalement aux marchés du pétrole, gaz et géothermie. Son expertise s'étend désormais dans les technologies de stockage de l'hydrogène (https://www.vallourec.com/fr/news/vallourec-revolutionne-le-stockage-dhydrogene-avec-delphy-sa-solution-verticale-a-grande-echelle/). Un aspect stratégique concerne le développement des connections premium permettant l'assemblage des tubes constituants les conduites rigides. La société Vallourec est leader sur ces technologies (connexions VAM®, Fig. 1a) mais cherche toujours à les améliorer. Ces conduites peuvent être montées et démontées ce qui peut induire à terme des phénomènes de grippage (transferts métalliques très adhésifs au sein des filets et portées internes) et potentiellement des problèmes de fuites au niveau des connexions. Aussi, afin de mieux comprendre et prédire ces phénomènes de dégradation et impact dans l'étanchéité, une thèse CIFRE de recherche est proposée en partenariat entre le centre de recherche Vallourec de Aulnoye-Aymeries (One RD-Au) et le laboratoire CDM de l'Ecole des Mines de Paris et le laboratoire LMPS de l'Ecole CentraleSupélec.
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Vallourec is a world leader in premium tubular solutions primarily serving the oil, gas, and geothermal markets. The company's expertise now also extends to hydrogen storage technologies (https://www.vallourec.com/fr/news/vallourec-revolutionne-le-stockage-dhydrogene-avec-delphy-sa-solution-verticale-a-grande-echelle/). A strategic focus lies in the development of premium connections that enable the assembly of tubes making up rigid pipelines. Vallourec is a leader in these technologies (VAM® connections, Fig. 1a) and is continuously seeking improvements. These pipelines can be assembled and disassembled, which can ultimately lead to galling phenomena (highly adhesive metal transfer within threads and internal shoulders), potentially causing sealing issues at the connections.
To better understand and predict these degradation phenomena and their impact on sealing performance, a CIFRE doctoral research project is proposed in partnership between the Vallourec Research Center in Aulnoye-Aymeries (One RD-Au), the CDM laboratory at Mines Paris, and the LMPS laboratory at CentraleSupélec.
Thesis Objectives and Program
Initial research efforts have led to the development of an experimental test rig known as RGT (Reduced Galling Testing), which simulates wear phenomena up to galling at a reduced scale. This test enabled the development of criteria for detecting galling, the study of different material pairs, and the proposal of a galling prediction model based on a frictional power dissipation approach at the interface [1, 2]. However, this test rig does not precisely replicate the geometric configuration of the contact nor the sliding kinematics. A primary objective of this thesis will be to deepen the experimental approach in order to allow for a direct correlation between these 'reduced-scale' tests and the results from technological tests conducted by Vallourec on actual connections.
Building on the RGT rig concept, the PhD candidate will use an improved version of the RGT*, equipped with a gas injection system that will allow the study of leak activation as a function of contact wear. Once this setup is operational, the candidate will carry out a series of experimental campaigns at CDM to study the tribosystem (phosphated carbon steel contact + grease) and the effects of loading cycles (variable loading + torsion), as well as the influence of contact geometry, particularly the difference between the previously studied flat-on-flat contact configuration and a torus-on-flat configuration, which is more representative. The experimental methodology could be supported by the acoustic emission technique, which has proven effective in the early detection of galling. This criterion will need to be compared with feedback from “full-scale” tests carried out by Vallourec.
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Début de la thèse : 01/10/2025

Cifre

CIFRE ANRT

Mines Paris-PSL

621 ISMME - Ingénierie des Systèmes, Matériaux, Mécanique, Énergétique

Ingénieur (Ecoles Centrales, INSA, Ecole des Mines, ENSTA, etc … et/ou Master recherche – Bon niveau de culture générale et scientifique. Bon niveau de pratique du français ou de l'anglais (niveau B2 ou équivalent minimum). Bonnes capacités d'analyse, de synthèse, d'innovation et de communication. Qualités d'adaptabilité et de créativité. Capacités pédagogiques. Motivation pour l'activité de recherche. Projet professionnel cohérent. Pré-requis (compétences spécifiques pour cette thèse) : Ing. Master en Mécanique et/ou Sciences des Matériaux Pour postuler : Envoyer votre dossier à recrutement_these@mat.mines-paristech.fr comportant • un curriculum vitae détaillé • une copie de la carte d'identité ou passeport • une lettre de motivation/projet personnel • des relevés de notes L3, M1, M2 • 2 lettres de recommandation • les noms et les coordonnées d'au moins deux personnes pouvant être contactées pour recommandation • une attestation de niveau d'anglais
Engineer and / or Master of Science - Good level of general and scientific culture. Good level of knowledge of French (B2 level in french is required) and English. (B2 level in english is required) Good analytical, synthesis, innovation and communication skills. Qualities of adaptability and creativity. Teaching skills. Motivation for research activity. Coherent professional project. Prerequisite (specific skills for this thesis): Applicants should supply the following : • a detailed resume • a copy of the identity card or passport • a covering letter explaining the applicant's motivation for the position • detailed exam results • two references : the name and contact details of at least two people who could be contacted • to provide an appreciation of the candidate • Your notes of M1, M2 • level of English equivalent TOEIC to be sent to recrutement_these@mat.mines-paristech.fr