References of "Lecomte-Beckers, Jacqueline"
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See detailDetermination of solidification parameters used for the prediction of the thixoformability of several steel alloys
Lecomte-Beckers, Jacqueline ULg; Rassili, Ahmed ULg; Robelet, Marc et al

in Solid State Phenomena (2006), 116-117

This paper focuses on the liquid fraction curves of several steels and the correlation between liquid fraction, temperature and heating rate. The work has been performed along two main axes. First, the ... [more ▼]

This paper focuses on the liquid fraction curves of several steels and the correlation between liquid fraction, temperature and heating rate. The work has been performed along two main axes. First, the solid fraction versus temperature has been obtained experimentally by differential scanning calorimetry (DSC), limited to low heating rates. Then, a shift of the liquid fraction curves has been noticed at high industrial heating rates. The quantification of this effect could not be carried out by DSC and required the elaboration of another experimental device. [less ▲]

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See detailInfluence of experimental parameters on properties and microstructure of the steel X210CrW12 in the semi-solid state
Fraipont, Céline; Puettgen, Wolfgang; Bleck, Wolfgang et al

in Solid State Phenomena (2006), 116-117

This paper deals with the examination of the steel grade X210CrW12 and its suitability for Thixoforming. In the semi-solid state, the microstructure of this steel consists of a homogeneous distribution of ... [more ▼]

This paper deals with the examination of the steel grade X210CrW12 and its suitability for Thixoforming. In the semi-solid state, the microstructure of this steel consists of a homogeneous distribution of globular particles surrounded by liquid. Additionally, carbides are stabile up to fraction liquid contents of approximately 40%. After quenching, this steel reveals a globular austenitic microstructure with eutectic (former liquid phase) at the grain boundaries. Compression tests permit to determine the influence of different process parameters on the properties and the material behaviour in the semi-solid state. Their influence on the microstructure was investigated but not yet highlighted. Further investigations on this steel allow a fine-tuning to establish optimal process windows of the different thixoforming- and rheoforming-routes. [less ▲]

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See detailCharacterization of Duplex steel Uranus 76N during deformation and heat treatment
Lecomte-Beckers, Jacqueline ULg; Moureaux, P.; Carton, Marc ULg et al

in Physica Status Solidi A. Applications and Materials Science (2006), 203(15), 3651-3664

Duplex Uranus 76N is characterized by metallography, thermal and mechanical analysis. The investigation shows that the microstructure of such a Duplex strongly depends on the cooling conditions ... [more ▼]

Duplex Uranus 76N is characterized by metallography, thermal and mechanical analysis. The investigation shows that the microstructure of such a Duplex strongly depends on the cooling conditions determining the quantity of austenite formed in the ferrite matrix. Numerical simulations of 76N behavior during the rolling process and service life require the knowledge of the recrystallization state during rolling steps at high temperature, thermal parameters such as dilatation, density, specific heat, thermal diffusivity, thermal conductivity and mechanical constitutive laws. These material parameters are determined and presented in this study. [less ▲]

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See detailEffect of boundary conditions and heat source distribution on temperature distribution in friction stir welding
Simar, A.; Lecomte-Beckers, Jacqueline ULg; Pardoen, T. et al

in Science & Technology of Welding & Joining (2006), 11(2), 170-177

on Al-6005A have been carried out using a fully instrumented milling machine. The power input was calculated from the measured torque and forces. The thermal cycles were measured at various locations ... [more ▼]

on Al-6005A have been carried out using a fully instrumented milling machine. The power input was calculated from the measured torque and forces. The thermal cycles were measured at various locations close to the weld centreline. A finite element pseudothermal model was developed, taking into account the influence of the welding parameters on the power input. The distribution of the total power input between surface and volume heat sources was also studied. The measured and predicted thermal cycles are in good agreement when proper contact conditions between the workpiece and the backing plate are introduced. [less ▲]

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See detailInfluence of carbide precipitation on hot hardness of high speed steel rolls
Herman, M.; Breyer, J. P.; Lecomte-Beckers, Jacqueline ULg

in Proceedings of the Southern African Roll Users' Conference (SARUC) (2006)

This paper will illustrate the choice of the alloying elements and their content in the current grade. By using sophisticated laboratory examination techniques such as differential thermal analysis ... [more ▼]

This paper will illustrate the choice of the alloying elements and their content in the current grade. By using sophisticated laboratory examination techniques such as differential thermal analysis, scanning electron microscopy and image analysis, the metallurgical parameters of Aurora grade will be described and compared to those of the Kosmos grade. An attempt will also be made to connect all our laboratory results to the good behaviour of the alloy in operation in the early stands of Hot Strip Mills. [less ▲]

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See detailMaterials for advanced power engineering 2006 : Proceedings of the 8th Liège conference
Lecomte-Beckers, Jacqueline ULg; Carton, Marc ULg; Schubert, F. et al

Book published by Schriften des Forschungszentrum Julich, Reihe energietechnik/Energy Technology Forschungszentrum Julich (2006)

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See detailthermal conductivity and microstructure
Lecomte-Beckers, Jacqueline ULg

Scientific conference (2005, May)

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See detailFinit element modelling of an asynchronous motor with one broken rotor bar, comparison with the data recorded on a prototype and material aspects
Guérard, Suzanne ULg; Gyselinck, Johan; Lecomte-Beckers, Jacqueline ULg

in Bulletin Scientifique de l'AIM (Association des Ingénieurs Electriciens sortis de l'Institut Electrotechnique Montefiore) (2005), 1

This work studies the problem of broken rotor bars in cage induction motors. To this aim, an induction machine from WEG Motors was modelled by means of the finite element method. The motor modelled is a ... [more ▼]

This work studies the problem of broken rotor bars in cage induction motors. To this aim, an induction machine from WEG Motors was modelled by means of the finite element method. The motor modelled is a 18.5 kW four-pole induction motor with a straight rotor cage. The field distribution and stator phase currents were computed for a motor without broken rotor bars and for a motor with one broken rotor bar. The computed stator phase currents were compared to the ones recorded on motors respectively no broken rotor bar and with one broken rotor bar. The FE model and an equivalent scheme of the motor permitted to show that the resistance of the rotor cage was higher than expected, considering only the temperature effect on the conductivity of the rotor bars. A metallurgic analysis of the aluminium alloy of two rotor bars revealed the presence of a very high density of silicon and silicon oxide inclusions, as well as the presence of shrinkages and cracks, which have a negative impact on both conductivity and mechanical strength. A corrected value of the rotor bar conductivity was used in the finite element model and led to a good agreement with the experimental results. The field perturbation associated with a broken rotor bar produces a concentration of flux near the bar ahead of the broken one, considering the counterclockwise direction of rotation of the rotor. This flux concentration results in higher current values and hence in higher stresses in the bar ahead of the broken one. [less ▲]

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See detailDetermination of the optimal forging conditions of a Cr-Mo-V high alloy steel through a microstructural, thermophysical and mechanical study
Bouffioux, Chantal ULg; Carton, Marc ULg; Lecomte-Beckers, Jacqueline ULg et al

in Banabic, D. (Ed.) Proceedings of the 8th ESAFORM Conference on Material Forming (Vol. 1) (2005)

The forging process of cylinders requires the knowledge of material recrystallisation conditions to prevent crack appearance. Due to the continuous recrystallisation during forging, very large ... [more ▼]

The forging process of cylinders requires the knowledge of material recrystallisation conditions to prevent crack appearance. Due to the continuous recrystallisation during forging, very large deformations can be applied as the generated dislocations do not yield to hardening but to recrystallisation phenomenon. This paper summarizes the data identification of a FEM recrystallisation model and defines the optimal forging process for one roll. [less ▲]

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See detailStudy of liquid fraction evolution of semi-solid steels for thixoforming
Lecomte-Beckers, Jacqueline ULg; Rassili, Ahmed ULg; Carton, Marc ULg et al

in Proceedings of the 8th ESAFORM Conference on Material Forming (2005)

Major challenge for semi-solid processing includes broadening the range of alloys that can be successfully thixoformed and developing alloys specifically for thixoforming. One important parameter is ... [more ▼]

Major challenge for semi-solid processing includes broadening the range of alloys that can be successfully thixoformed and developing alloys specifically for thixoforming. One important parameter is appropriate solidus-liquidus interval. The wider the solidification interval, the wider the processing window. This study is related to the experimental determination of this critical parameter on eight different steel compositions. This parameter was obtained using Differential Scanning Calorimetry. This technique allows to obtain the solid fraction versus temperature. [less ▲]

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See detailUse of Microscopy for identification of complex MC, M2C, M6C, M7C3 and M23C6 carbides in high speed-steels
Lecomte-Beckers, Jacqueline ULg; Tchuindjang, Jérôme Tchoufack ULg

in GIT - Imaging and Microscopy (2005), 2

High-speed steels (HSSJ rofis are useci in front finishing stands of hot strip mils. Good wear resistance and hardness at high temperature are defining features of HSS. Many types of carbides are present ... [more ▼]

High-speed steels (HSSJ rofis are useci in front finishing stands of hot strip mils. Good wear resistance and hardness at high temperature are defining features of HSS. Many types of carbides are present in these alloys, each having different effect upon the final properties of HSS. As a resuit, nature, morphology and amount of these carbides are factors of important concern. Identification and characterisation of HSS carbides are realised with optical microscopy comhined with electron microscopy. [less ▲]

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