During irradiation in a nuclear reactor, the UO2 fuel and the Zr cladding come into contact due t... more During irradiation in a nuclear reactor, the UO2 fuel and the Zr cladding come into contact due to fuel thermal expansion and cladding creep. The inner surface of the Zr cladding in contact with the UO2 fuel therefore oxidizes. This paper analyzes the microstructure of zirconia formed at the Zr cladding/UO2 interface in two samples with different burnups. It seems that the zirconia develops ‘normally’ until it comes into contact with the fuel. The development of internal zirconia is, however, constrained mechanically by the contact of the UO2 fuel. Four different zones can be distinguished in the zirconia layer of each sample. In the medium-burnup sample (37 GWd/tU), the zirconia in the first zone in contact with the cladding exhibits the same kind of microstructure as ‘ordinary’ zirconium oxide formed on the cladding outer surface, which is characterized by columnar and equiaxed grains. Thereafter, two intermediate zones can be observed: a first composed of very small equiaxed grains and a second with a mixture of intermediate and large grains. In the high-burnup sample (61 GWd/tU), zirconia presents a wavy interface with some circumvolutions. The ZrO2 in contact with the fuel is more developed in this case than in the medium-burnup sample, but it shows the same microstructure.
Synthèse : Revue des Sciences et de la Technologie, 2015
Un essai de flexion quatre points est utilise pour simuler la sollicitation mecanique a laquelle ... more Un essai de flexion quatre points est utilise pour simuler la sollicitation mecanique a laquelle sont soumises les brames d'acier pendant la sequence de laminage dans une plage de temperature comprise entre 900°C et 650°C. L'examen par MEB de la surface des specimens testes en flexion sous une atmosphere controlee fournit des informations supplementaires sur la fissuration de la bande d'oxyde, sur le type de defaillance et sur les differents defauts. Cette analyse montre que les temperatures de formation de la couche d'oxyde ou calamine et la sollicitation mecanique ont une influence significative sur le comportement du systeme acier-calamine. Les couches d'oxydes obtenues sous une atmosphere humide ont un comportement plus plastique que celles obtenues sous une atmosphere seche. Mots cles: Laminage a chaud- Flexion 4points - Acier- Oxydation- Calamine Effect of temperature on the microstructure of the oxide layers formed on the high carbon steel during hot rolling process A four bending test is used to simulate the mechanical solicitation subjected by the steel slabs during the rolling sequence in a temperature range between 900°C and 650°C. The review by SEM of the surface of the specimens deformed provides additional information on the cracking of the oxide band, on the type of failure and the different faults. It is shown that the temperatures of formation of the oxide layer and mechanical solicitation have a significant influence on the behavior of the system steel- calamine. Oxide coatings obtained under wet atmosphere have a behavior more plastic than those obtained under dry atmosphere. Keywords: Hot rolling- Four point bending - Steel- Oxidation- Calamine
Abstract A comparison of measurements performed in in-situ conditions using Raman spectroscopy an... more Abstract A comparison of measurements performed in in-situ conditions using Raman spectroscopy and Deflection Test in Monofacial Oxidation techniques were employed to study stress states developed in zirconia films grown at 500 °C is presented. The results show a good correlation between recorded Raman peak displacement and sample deflection angle. Considering analyzed volume of the material, Raman analysis represents a local measurement while the deflection test is a global response of the material. Reported stress components: (i) hydrostatic – resulted from Raman spectroscopy and (ii) in-plane – resulted from deflection test technique have been analyzed in comparison to each of the described techniques and aim to explain the behavior of zirconia at high temperatures.
L'analyse de l'influence des procedes de fabrication d'une vis en 37Cr4 sur sa struct... more L'analyse de l'influence des procedes de fabrication d'une vis en 37Cr4 sur sa structure metallurgique a permis de comprendre les interactions matiere/process pouvant aboutir a une rupture differee introduite par une fragilisation par l'hydrogene.
L'Inconel 600, un alliage base nickel (NC15Fe), utilisé au niveau des tubes des générateurs d... more L'Inconel 600, un alliage base nickel (NC15Fe), utilisé au niveau des tubes des générateurs de vapeur (GV) des réacteurs nucléaires à eau pressurisée, est susceptible à la corrosion inter-granulaire. La connaissance de son état de surface est essentielle pour assurer les conditions de bon fonctionnement des GV. Au cours de ce travail, l'émission acoustique (EA) est utilisée afin de déceler l'endommagement éventuel d'un ensemble d'éprouvettes oxydées à température constante sous contrainte mécanique. L'article comprend les résultats issus de ces essais expérimentaux relativement originaux : flexion 4 points dans l'intervalle de température 350-550°C à une vitesse de sollicitation 2.10 -3 mm/s. Les essais sont réalisés au moyen d'un montage spécifique, sous atmosphère contrôlée, in situ, (vide, oxygène et vapeur d'eau) suivis simultanément par EA grâce à une chaîne d'acquisition reliée au montage. Les signatures acoustiques enregistrées durant c...
2009 IEEE International Conference on Mechatronics, 2009
... CNRS 6253, Universite de Technologie de Compiegne, Compiegne, France 2 Laboratoire de Physiqu... more ... CNRS 6253, Universite de Technologie de Compiegne, Compiegne, France 2 Laboratoire de Physique de la Matiere Condensee EA2081, Universite Picardie Jules Verne, Amiens, France syed-sajid-hussain.zaidi ... This curve also provides the values for As> Ar, Ms and Mr (Fig. ...
In the context of the prediction of materials durability in multiphysics aggressive environments,... more In the context of the prediction of materials durability in multiphysics aggressive environments, we present a numerical model which is able to describe the phenomenon of the oxide layer fracture after the formation of the oxide for Zr/ZrO2 system. In order to evaluate the characteristic distance of the periodic crack pattern in the oxide layer and the debonding of the
During irradiation in a nuclear reactor, the UO2 fuel and the Zr cladding come into contact due t... more During irradiation in a nuclear reactor, the UO2 fuel and the Zr cladding come into contact due to fuel thermal expansion and cladding creep. The inner surface of the Zr cladding in contact with the UO2 fuel therefore oxidizes. This paper analyzes the microstructure of zirconia formed at the Zr cladding/UO2 interface in two samples with different burnups. It seems that the zirconia develops ‘normally’ until it comes into contact with the fuel. The development of internal zirconia is, however, constrained mechanically by the contact of the UO2 fuel. Four different zones can be distinguished in the zirconia layer of each sample. In the medium-burnup sample (37 GWd/tU), the zirconia in the first zone in contact with the cladding exhibits the same kind of microstructure as ‘ordinary’ zirconium oxide formed on the cladding outer surface, which is characterized by columnar and equiaxed grains. Thereafter, two intermediate zones can be observed: a first composed of very small equiaxed grains and a second with a mixture of intermediate and large grains. In the high-burnup sample (61 GWd/tU), zirconia presents a wavy interface with some circumvolutions. The ZrO2 in contact with the fuel is more developed in this case than in the medium-burnup sample, but it shows the same microstructure.
Synthèse : Revue des Sciences et de la Technologie, 2015
Un essai de flexion quatre points est utilise pour simuler la sollicitation mecanique a laquelle ... more Un essai de flexion quatre points est utilise pour simuler la sollicitation mecanique a laquelle sont soumises les brames d'acier pendant la sequence de laminage dans une plage de temperature comprise entre 900°C et 650°C. L'examen par MEB de la surface des specimens testes en flexion sous une atmosphere controlee fournit des informations supplementaires sur la fissuration de la bande d'oxyde, sur le type de defaillance et sur les differents defauts. Cette analyse montre que les temperatures de formation de la couche d'oxyde ou calamine et la sollicitation mecanique ont une influence significative sur le comportement du systeme acier-calamine. Les couches d'oxydes obtenues sous une atmosphere humide ont un comportement plus plastique que celles obtenues sous une atmosphere seche. Mots cles: Laminage a chaud- Flexion 4points - Acier- Oxydation- Calamine Effect of temperature on the microstructure of the oxide layers formed on the high carbon steel during hot rolling process A four bending test is used to simulate the mechanical solicitation subjected by the steel slabs during the rolling sequence in a temperature range between 900°C and 650°C. The review by SEM of the surface of the specimens deformed provides additional information on the cracking of the oxide band, on the type of failure and the different faults. It is shown that the temperatures of formation of the oxide layer and mechanical solicitation have a significant influence on the behavior of the system steel- calamine. Oxide coatings obtained under wet atmosphere have a behavior more plastic than those obtained under dry atmosphere. Keywords: Hot rolling- Four point bending - Steel- Oxidation- Calamine
Abstract A comparison of measurements performed in in-situ conditions using Raman spectroscopy an... more Abstract A comparison of measurements performed in in-situ conditions using Raman spectroscopy and Deflection Test in Monofacial Oxidation techniques were employed to study stress states developed in zirconia films grown at 500 °C is presented. The results show a good correlation between recorded Raman peak displacement and sample deflection angle. Considering analyzed volume of the material, Raman analysis represents a local measurement while the deflection test is a global response of the material. Reported stress components: (i) hydrostatic – resulted from Raman spectroscopy and (ii) in-plane – resulted from deflection test technique have been analyzed in comparison to each of the described techniques and aim to explain the behavior of zirconia at high temperatures.
L'analyse de l'influence des procedes de fabrication d'une vis en 37Cr4 sur sa struct... more L'analyse de l'influence des procedes de fabrication d'une vis en 37Cr4 sur sa structure metallurgique a permis de comprendre les interactions matiere/process pouvant aboutir a une rupture differee introduite par une fragilisation par l'hydrogene.
L'Inconel 600, un alliage base nickel (NC15Fe), utilisé au niveau des tubes des générateurs d... more L'Inconel 600, un alliage base nickel (NC15Fe), utilisé au niveau des tubes des générateurs de vapeur (GV) des réacteurs nucléaires à eau pressurisée, est susceptible à la corrosion inter-granulaire. La connaissance de son état de surface est essentielle pour assurer les conditions de bon fonctionnement des GV. Au cours de ce travail, l'émission acoustique (EA) est utilisée afin de déceler l'endommagement éventuel d'un ensemble d'éprouvettes oxydées à température constante sous contrainte mécanique. L'article comprend les résultats issus de ces essais expérimentaux relativement originaux : flexion 4 points dans l'intervalle de température 350-550°C à une vitesse de sollicitation 2.10 -3 mm/s. Les essais sont réalisés au moyen d'un montage spécifique, sous atmosphère contrôlée, in situ, (vide, oxygène et vapeur d'eau) suivis simultanément par EA grâce à une chaîne d'acquisition reliée au montage. Les signatures acoustiques enregistrées durant c...
2009 IEEE International Conference on Mechatronics, 2009
... CNRS 6253, Universite de Technologie de Compiegne, Compiegne, France 2 Laboratoire de Physiqu... more ... CNRS 6253, Universite de Technologie de Compiegne, Compiegne, France 2 Laboratoire de Physique de la Matiere Condensee EA2081, Universite Picardie Jules Verne, Amiens, France syed-sajid-hussain.zaidi ... This curve also provides the values for As> Ar, Ms and Mr (Fig. ...
In the context of the prediction of materials durability in multiphysics aggressive environments,... more In the context of the prediction of materials durability in multiphysics aggressive environments, we present a numerical model which is able to describe the phenomenon of the oxide layer fracture after the formation of the oxide for Zr/ZrO2 system. In order to evaluate the characteristic distance of the periodic crack pattern in the oxide layer and the debonding of the
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