Littérature scientifique sur le sujet « Procédé de refusion »
Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres
Sommaire
Consultez les listes thématiques d’articles de revues, de livres, de thèses, de rapports de conférences et d’autres sources académiques sur le sujet « Procédé de refusion ».
À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.
Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.
Articles de revues sur le sujet "Procédé de refusion"
Saleil, Jean, Marc Mantel et Jean Le Coze. « La production des aciers inoxydables : Histoire de son développement et des procédés de fabrication. Partie II. Évolutions de l’élaboration des aciers inoxydables au four électrique à arc. La tentation de la fonte au chrome et la production d’aciers inoxydables dans l’usine intégrée ». Matériaux & ; Techniques 108, no 1 (2020) : 104. http://dx.doi.org/10.1051/mattech/2020017.
Texte intégralBellot, J. P., E. Floris, E. Hess et D. Ablitzer. « Simulation du comportement thermique et hydrodynamique du titane dans le four à surverse du procédé de refusion par bombardement électronique ». Revue de Métallurgie 91, no 12 (décembre 1994) : 1777–86. http://dx.doi.org/10.1051/metal/199491121777.
Texte intégralMompó, Jacob. « Negar el dogma de la Transsubstanciació. El procés inquisitorial contra Antoni Moxó (1504-1505), el convers que ‘no volia rebre lo cors preciós de Jesucrist’ ». SCRIPTA. Revista Internacional de Literatura i Cultura Medieval i Moderna 21, no 21 (22 juin 2023) : 369. http://dx.doi.org/10.7203/scripta.21.26838.
Texte intégralJARDY, Alain, Stéphane HANS, Sylvain CHARMOND et Alexandre DEVAUX. « Procédé de refusion sous laitier électroconducteur (ESR) ». Élaboration et recyclage des métaux, juin 2019. http://dx.doi.org/10.51257/a-v1-m7820.
Texte intégralJARDY, Alain, Isabelle CRASSOUS, Sylvain CHARMOND, Vincent DESCOTES, Stéphane HANS et Yvon MILLET. « Procédé de refusion à l’arc sous vide (VAR) ». Élaboration et recyclage des métaux, janvier 2022. http://dx.doi.org/10.51257/a-v1-m7822.
Texte intégralThèses sur le sujet "Procédé de refusion"
Weber, Valentine. « Simulation numérique du procédé de refusion sous laitier électroconducteur ». Thesis, Vandoeuvre-les-Nancy, INPL, 2008. http://www.theses.fr/2008INPL010N/document.
Texte intégralElectro Slag Remelting (ESR) is widely used for the production of high-value-added alloys such as special steels or nickel-based superalloys. Because of high trial costs and complexity of the process, trial-and-error based approaches are not well suitable for fundamental studies and optimization of the process.Consequently, a transient-state numerical model which accounts for electromagnetic phenomena and coupled heat and momentum transfers in an axisymmetrical geometry has been developed. The model simulates the continuous growth of the electroslag remelted ingot through a mesh-splitting method. In addition, solidification of the metal and slag is modelled by an enthalpy-based technique. A turbulence model is implemented to compute the motion of liquid phases (slag and metal), while the mushy zone is described as a porous medium whose permeability varies with the liquid fraction, thus enabling an accurate calculation of solid/liquid interaction. The coupled partial differential equations are solved using a finite-volume technique.Computed results are compared to experimental observation of 4 industrial remelted ingots fully dedicated to the model validation step. Pool depth and shape are particularly investigated in order to validate the model. Comparison shows that the model can be used as a predictive tool to analyse the process behavior. Nevertheless, it is necessary to pay a particular attention to the estimation of the thermophysical properties of metal and especially slag.These results provide valuable information about the process performance and influence of operating parameters. In this way, we present some examples of model use as a support to analyse the influence of operating parameters. We have studied the variation of electrode immersion depth, fill ratio and water pressure in the cooling circuit
Hugo, Mathilde. « Contribution à la modélisation du procédé de refusion sous laitier éléctroconducteur ». Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0091.
Texte intégralThe ElectroSlag Remelting process (ESR) is widely used to produce high added value alloys for critical applications (aerospace industry, nuclear plants, etc.). Trial-and-error based approaches being expensive, numerical simulation is fundamental to improve the knowledge and the understanding of this complex process. The Institut Jean Lamour has been developing for several years a numerical code to simulate the melting of a consumable electrode, supposedly perfectly cylindrical, within a mold assumed to be perfectly electrically insulated from the electrode-slag-ingot system. Based on these assumptions, the 2-D axisymmetrical transient-state numerical model accounts for electromagnetic phenomena and coupled heat and momentum transfers, to simulate the continuous growth of the electroslag remelted ingot and the solidification of the metal and slag. Recent studies on the ESR process are challenging the insulated mold hypothesis. Therefore, the main objective of the thesis is to acknowledge and study the existence of a mold current during an ESR remelting. A first model has been set-up, aimed to simulate the electromagnetic phenomena in the whole system for a simplified geometry. The possibility of the existence of such a mold current was confirmed. Based on this work, a fully-coupled model has then been developed and the results have been compared with experimental data to check the validity of the modifications. The influence of slag properties and operating parameters on the final quality of the ingot has been tested
Chapelle, Pierre. « Étude expérimentale et modélisation de l'arc électrique dans le procédé de refusion var ». Vandoeuvre-les-Nancy, INPL, 2001. http://www.theses.fr/2001INPL004N.
Texte intégralChaulet, Jérémy. « Modélisation du procédé de refusion sous laitier électroconducteur : représentation des transferts énergétiques métal-laitier ». Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0145.
Texte intégralThe electroslag remelting process (ESR) is used to produce high added value alloys characterized by a higher metallurgical quality. These alloys are reserved for specific industries, such as aeronautics or energy. Numerical modeling of the ESR process is a tool-of-choice to gain a better understanding of the phenomena occurring during the remelting and optimize the operation. In order to improve a 2D axisymmetric model of the ESR process, previously developed at the Jean Lamour Institute in close collaboration with Aubert & Duval company, an accurate description of the metal transfers to the ingot via the liquid metal droplets has been developed. First of all, liquid metal droplets behavior has been investigated using a specifically developed 2D diphasic model of the slag bath. This model has been supported by 3D detailed simulations of dripping phenomena during electroslag remelting, performed at Montanuniversitaet Leoben (Austria). The influence of falling drops on the slag hydrodynamics, heat tranfer and electromagnetic phenomena has been highlighted. Afterwards, a simplified model of drops-slag interactions has been implemented into the global ESR model. The liquid metal transfer representation at the top of the ingot has then been enhanced, and considers the in-depth impact on the melt pool. The newly developed version of the global model has been validated by comparing results to industrial-sized remelted ingots. In order to discuss the relationship between power consumed and melt rate, a 1D thermal model of the consumable electrode has been set-up. The latter has been implemented into the global ESR model to estimate the melt rate. Finally, industrial-scale ingots have been specially remelted to study the influence of electrode immersion depth. Associating experimental observations and simulation results, three immersion regimes have been distinguished, especially regarding to the slag equivalent resistance. The impact of immersion depth on ingot solidification have been discussed
Banos, Julien. « Modélisation du procédé de refusion à l’arc sous vide : Échanges thermiques et défauts de solidification ». Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0117.
Texte intégralThe Vacuum Arc Remelting (VAR) process is used in the production of high-added value metals such as titanium alloys or nickel-based superalloys for the aerospace industry. The control of solidification conditions is an important industrial issue in order to process ingots of adequate chemical homogeneity and free of solidification defects. The work presented in this manuscript aims at improving the description of heat exchanges in a VAR process model (SOLAR) and at proposing a new approach for the prediction of segregated channels type solidification defects. First, the description of the heat exchanges in the model between the electrode, the ingot, the mould and the cooling circuit has been improved. These modifications were validated by comparing the numerical results with measurements from real industrial melts. An original experimental apparatus for measuring the external mould temperature adapted to industrial melts was designed. This apparatus was used during an experimental campaign on an industrial site during the remelting of a titanium alloy. The measurements obtained were compared with the numerical results from SOLAR. These two activities led to a first implementation of the side-arcing phenomenon in the model. In parallel, a multi-scale numerical approach was developed to predict the formation of segregated channels as a function of local solidification conditions. A first study on a Sn-Pb alloy was carried out and a mathematical criterion was calculated from the results. This first study shows a much lower impact of the thermal gradient on the formation of segregated channels than that generally considered in the literature
Liu, Jiangwei. « Maîtrise du procédé hybride de projection thermique avec refusion laser in-situ : approches numérique et expérimentale ». Thesis, Belfort-Montbéliard, 2016. http://www.theses.fr/2016BELF0284/document.
Texte intégralThe hybrid spraying process consisting in plasma spraying and laser remelting is an alternative method to minimize or even eliminate the potential defects within the as-sprayed coatings.During the treatment of plasma spraying or laser remelting, the substrate/coating system undergoing heating, melting, solidification and fast cooling processes is submitted to high temperature gradients, high stress levels and even risks of crack formation. It is therefore important to control the temperature variation and stress level within the substrate/coating system. In this study, thermal and mechanical models established with ANSYS were developed to provide a fundamental understanding of thermal and mechanical behaviors of deposited coatings during plasma spraying and laser remelting processes.3D simulation models were first developed to predict the temperature field, the final deformation of the specimen, and the residual stresses within ceramic (alumina) and metallic (NiCrBSi) coatings. The final residual stresses result from the balance between quenching stresses (tensile) and thermal stresses (compressive or tensile). Due to the low value of the yield stress, the thermal stresses (compressive for that case) dominate the final stress level in the case of the ceramic coating (alumina). On the contrary, the final residual stresses within the NiCrBSi coating are tensile. It is also predicted that an increase of the cooling efficiency induces a lower stress level for the alumina coating, while improving the cooling efficiency slightly increases the residual stresses for the case of the metallic coating (NiCrBSi).Thermal analysis to predict laser post-remelting of a NiCrBSi coating was then carried out to investigate the effects of the laser parameters on the temperature field as well as on the remelted pool shape. An absorption coefficient of 0.5 was estimated by comparison of the remelted pool depths obtained by experimental and numerical methods. In addition, the morphologies of theremelted coating were characterized by experimental methods. According to the mechanical analysis for laser post-remelting of NiCrBSi coatings, the predicted residual stresses were tensile within the remelted coating, whereas those within the non- emelted zone were reversed from tensile before remelting to compressive after laser post-remelting. According to the numerical analysis of in situ laser remelting by a multi-layer model, transient stresses in the former deposited layers were decreased progressively due to the heat accumulation during the following deposition process. For the residual stresses after final cooling, the stress component along the displacement direction presents a higher level in comparison with the transverse andthrough thickness components. Solutions allowing decreasing the stress level within the remelted coating were studied by changing the cooling efficiency and the initial temperature of the substrate. It was noted that the generated residual stress (tensile) was more sensitive to the initial temperature of the substrate, than to the efficiency of the cooling system. In particular, increasing the initial temperature of the substrate could significantly decrease the stress magnitude within the remelted coating, and even reverse the residual stresses within the nonremelted part of the coating to compressive values
Antou, Guy. « Améliorations de revêtements barrières thermiques par un procédé de refusion laser in situ utilisant un laser à diodes ». Strasbourg 1, 2004. https://publication-theses.unistra.fr/public/theses_doctorat/2004/ANTOU_Guy_2004.zip.
Texte intégralYttria partially stabilized zirconia thermal barrier coatings (TBCs) are nowadays widely used to protect components of aero gas turbines against degradation at high temperature, corrosion and oxidation. However, these coatings degrade in service conditions. Therefore, to manufacture TBC which present both low thermal conductivity and high life-time is a real challenge. Engineering the coating architecture by an adapted process is a prerequise to modify TBC characteristics. In this study, laser remelting was combined to thermal spraying in order to modify the TBC properties. The purpose was to adapt TBC characteristics during their manufacturing process, without adding one or even more additional steps. In situ laser treatment (i) changes structure from lamellar to dendritic columnar; (ii) generates a pore architecture less sensitive to sintering, inducing then a best conservation of the thermal and mechanical properties during thermal treatments at high temperatures; (iii) improves the thermal insulation properties of the TBC by decreasing its thermal conductivity of about 30 %; (iv) decreases its permeability in order to diminish oxidation and corrosion phenomena; (v) increases the resistance to isothermal shocks (with the possibility to double the number of cycles); (vi) conducts to a metastable tetragonal phase more stable during thermal shocks; (vii) without modifying elastic response of the deposit
Soller, Aude. « Refusion à l'arc sous vide du superalliage 718 : modélisation du procédé et étude de la formation des "white spots" ». Vandoeuvre-les-Nancy, INPL, 2006. http://docnum.univ-lorraine.fr/public/INPL/2006_SOLLER_A.pdf.
Texte intégralSome very detrimental defects, called white spots, can form during the remelting of Alloy 718. Depleted in alloying elements, they are supposed to be generated by the fall of solid metallic precursors in the liquid pool. In a first step, a model aimed to simulate the remelting process, based on the SOLAR software, has been adapted to the remelting of Alloy 718, then validated by comparison between the simulation results and experimental observations of a remelted ingot. The characterization of electrodes and ingots has shown that large dendrites in the electrode could be the origin of dendritic white spots. This study also determines quantitatively the main characteristics of the three possible sources of discrete white spot precursors (electrode torus, shelf and crown) in terms of structure, composition and size. “Dipping” experiments of synthetic discrete white spots precursors allow a direct measurement of their melting kinetics. These results qualitatively validate a numerical model which describes the melting/solidification process of a spherical particle immerged in a liquid metal bath. Last, the behaviour of a discrete white spot in the liquid pool of a VAR ingot is determined through coupling the phase change model to a calculation of the precursor trajectory. The hydrodynamic and thermal behaviour of the liquid pool is calculated by SOLAR and the characteristics of each of the potential precursor origins are taken into account as input data. The overall model computes, for each origin, a precursor critical size leading to the formation of a white spot
Décultot, Léa. « Étude et modélisation du procédé de refusion par plasma d’arc en creuset froid (PAMCHR) d’alliages de titane pour des applications aéronautiques ». Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0031.
Texte intégralThe recycling of titanium scraps can be achieved using the Plasma Arc Melting Cold Hearth Refining (PAMCHR) process with the aim of producing aeronautical titanium alloy ingots. In this manuscript, the research work focuses on the refining stage of the process where the liquid is transported in a horizontal copper water-cooled crucible. This important step takes place downstream the melting of the charge and upstream the casting of liquid titanium into the ingot mold crucible. Plasma torches are used as heat source of PAMCHR process, which is conducted under an atmosphere of inert gas. A three-dimensional modeling of the thermo-hydrodynamic flow of the titanium alloy has been set up based on Ansys-Fluent CFD software. The purpose of this tool, named PAM3D, is to improve our understanding of the liquid titanium behavior within the refining crucible. A large number of user functions have been integrated into the model to describe, among other mechanisms, the thermal and momentum transferred from the plasma plume to the surface of the liquid bath. The analysis of these transfers is essential for modeling the process. They are obtained by a study coupling melting tests, carried out in a pilot PAMCHR furnace, and numerical modeling. Numerical results, obtained by this first version of PAM3D are compared to experimental measurements, and the agreement is satisfactory. However, the maximum value of the shear stress, due to the impact of the plasma plume on the bath surface, implemented in the model seems to be underestimated. Moreover, complementary simulations highlight the important role of hydrodynamic forces on the thermal behavior of the bath, and in particular of this shear stress
Revil-Baudard, Mathieu. « Modélisation et étude de la macroségrégation au cours de la refusion à l'arc sous vide : application aux alliages de zirconium ». Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0297/document.
Texte intégralVacuum Arc Remelting (VAR) is used to produce high performance alloys for the aeronautic (special steels, superalloys, titanium alloys) and nuclear (zirconium alloys) industries. As for all casting processes, the control of the chemical homogeneity and the metallurgical structure in VAR ingots is an important industrial issue. The goal of this thesis is to identify, for zirconium alloys in particular, the effects of the natural convection and the forced convection due to the electromagnetic stirring on macrosegregation. To this purpose, a numerical model has been developed. It is based on the solution of the coupled transient energy, momentum and solute transport equations, under laminar or turbulent flow conditions. The solidification modeling accounts for a full coupling between energy and solute transport in the mushy zone. The finite diffusion of solutes in both solid and liquid phases can be taken into account to describe microsegregation. In addition, chemically homogeneous Zircaloy-4 and M5® electrodes have been specially remelted in an industrial VAR furnace at the CEZUS plant in Ugine (Savoie, France). The macrosegregation of the ingots has been measured. The comparison between the experimental measurements and the simulation results showed that for an alloy with a large solidification interval (like Zircaloy-4), the solutal convection in the mushy zone could have an essential influence on the macrosegregation in the inner part of the ingot. Furthermore, the motion of equiaxed grains caused by a strong stirring seems to seriously intensify macrosegregation in the outer part of the ingot. For an alloy with a small solidification interval (like M5®), we have shown that the macrosegregation depends more specifically on the forced convection due to the type of stirring applied during the remelting