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J. Bourgon - One of the best experts on this subject based on the ideXlab platform.

  • Wetting by Liquid Sodium and fracture path analysis of Sodium induced embrittlement of 304L stainless steel
    Journal of Materials Research, 2018
    Co-Authors: Bassem Barkia, Thierry Auger, J. L. Courouau, J. Bourgon
    Abstract:

    The wettability of the 304L steel is an important parameter in Liquid Metal Embrittlement studies. Empirically, it is found to be greatly enhanced by pre-exposure to oxygenated Liquid Sodium. The corrosion interface formed during exposure to Sodium has been analyzed at the nanoscale by transmission electron microscopy using the focused ion beam sampling. A thin layer of Sodium chromite (Na xCrO2 with x ≤ 1) is detected at the interface validating wetting on an oxide mechanism for the enhanced wetting after pre-exposure. Fracture micromechanisms and the crack path of Liquid Sodium-embrittled austenitic steel 304L at 573 K have been investigated down to the nanoscale. High-resolution orientation mapping analyses immediately below the fracture surface show that abundant martensitic transformations (γ → α) and twinning occur during deformation of austenite. The preferential crack path is intergranular along the newly formed γ/γ interfaces. It is concluded that these transformations play a major role in the fracture process.

  • Multiscale investigation of crack path and microstructural changes during Liquid metal embrittlement of 304L austenitic steel in Liquid Sodium
    Corrosion Science, 2017
    Co-Authors: Bassem Barkia, Thierry Auger, J. L. Courouau, J. Bourgon
    Abstract:

    Abstract Fracture micro-mechanisms and crack path of embrittled austenitic steel 304L by Liquid Sodium strained at 4.2 × 10−7 m s−1 and 573 K are investigated underneath the fracture surface by transmission electron microscopy down to the nanoscale. Automated crystal orientation and phase mapping analyses show that abundant martensitic transformation (γ austenite → α’ martensite) as well as mechanical twinning occur during the deformation of austenite and play a major role in the fracture process. A correlation between the fracture surface features and the underlying microstructural interfaces is evidenced, strengthening the conclusion that Liquid metal embrittlement by Sodium of austenitic steels is basically an interfacial cracking phenomenon.

J. L. Courouau - One of the best experts on this subject based on the ideXlab platform.

  • investigation of crack propagation resistance of 304l 316l and 316l n austenitic steels in Liquid Sodium
    Journal of Nuclear Materials, 2018
    Co-Authors: Bassem Barkia, J. L. Courouau, E Perrin, Veronique Lorentz, Matthieu Rivollier, Raphael Robin, Laetitia Nicolas, Celine Cabet, T Auger
    Abstract:

    In order to assess the susceptibility of candidate structural materials to Liquid Metal Embrittlement (LME), the fracture behavior of three grades of austenitic steels was investigated in oxygenated (200 wppm) Liquid Sodium in the temperature range [473–673 K] on notched axisymmetric tensile specimens. The tests were carried out in an inert glove box at very low concentrations of dioxygen and humidity (<1 ppm) to prevent further contamination after pre-exposure in oxygenated Liquid Sodium. A decrease in crack propagation resistance of the three austenitic steels (304 L, 316 L(N), 316 L) is observed in oxygenated Liquid Sodium (200 wppm) from 573, 623 and 673 K respectively after pre-wetting in oxygenated Sodium. This reduction is correlated with a ductile to brittle change of the fracture surface. This effect observed with the three austenitic steels is attributed to the onset of LME after significant plastic deformation.

  • Wetting by Liquid Sodium and fracture path analysis of Sodium induced embrittlement of 304L stainless steel
    Journal of Materials Research, 2018
    Co-Authors: Bassem Barkia, Thierry Auger, J. L. Courouau, J. Bourgon
    Abstract:

    The wettability of the 304L steel is an important parameter in Liquid Metal Embrittlement studies. Empirically, it is found to be greatly enhanced by pre-exposure to oxygenated Liquid Sodium. The corrosion interface formed during exposure to Sodium has been analyzed at the nanoscale by transmission electron microscopy using the focused ion beam sampling. A thin layer of Sodium chromite (Na xCrO2 with x ≤ 1) is detected at the interface validating wetting on an oxide mechanism for the enhanced wetting after pre-exposure. Fracture micromechanisms and the crack path of Liquid Sodium-embrittled austenitic steel 304L at 573 K have been investigated down to the nanoscale. High-resolution orientation mapping analyses immediately below the fracture surface show that abundant martensitic transformations (γ → α) and twinning occur during deformation of austenite. The preferential crack path is intergranular along the newly formed γ/γ interfaces. It is concluded that these transformations play a major role in the fracture process.

  • Investigation of crack propagation resistance of 304L, 316L and 316L(N) austenitic steels in Liquid Sodium
    Journal of Nuclear Materials, 2018
    Co-Authors: Bassem Barkia, J. L. Courouau, E Perrin, Veronique Lorentz, Matthieu Rivollier, Raphael Robin, Laetitia Nicolas, Celine Cabet, Thierry Auger
    Abstract:

    In order to assess the susceptibility of candidate structural materials to Liquid Metal Embrittlement (LME), the fracture behavior of three grades of austenitic steels was investigated in oxygenated (200 wppm) Liquid Sodium in the temperature range [473–673 K] on notched axisymmetric tensile specimens. The tests were carried out in an inert glove box at very low concentrations of dioxygen and humidity (

  • Multiscale investigation of crack path and microstructural changes during Liquid metal embrittlement of 304L austenitic steel in Liquid Sodium
    Corrosion Science, 2017
    Co-Authors: Bassem Barkia, Thierry Auger, J. L. Courouau, J. Bourgon
    Abstract:

    Abstract Fracture micro-mechanisms and crack path of embrittled austenitic steel 304L by Liquid Sodium strained at 4.2 × 10−7 m s−1 and 573 K are investigated underneath the fracture surface by transmission electron microscopy down to the nanoscale. Automated crystal orientation and phase mapping analyses show that abundant martensitic transformation (γ austenite → α’ martensite) as well as mechanical twinning occur during the deformation of austenite and play a major role in the fracture process. A correlation between the fracture surface features and the underlying microstructural interfaces is evidenced, strengthening the conclusion that Liquid metal embrittlement by Sodium of austenitic steels is basically an interfacial cracking phenomenon.

  • Liquid metal embrittlement of an austenitic stainless steel in Liquid Sodium
    Corrosion Science, 2014
    Co-Authors: S. Hémery, Thierry Auger, J. L. Courouau, F. Balbaud-célérier
    Abstract:

    Abstract A Fe18Cr9Ni1Mn austenitic stainless steel is shown to be sensitive to Liquid metal embrittlement in Liquid Sodium. Good wetting by Sodium is achieved during long-term pre-exposure before tensile testing in Liquid Sodium with additions of Na 2 O. Pre-exposure does not affect the normal ductile fracture mode of the steel in reference tests in the temperature range investigated ([473–673 K]). Intergranular cracking is found to play a key role in the fracture process in Liquid Sodium.

Thierry Auger - One of the best experts on this subject based on the ideXlab platform.

  • Wetting by Liquid Sodium and fracture path analysis of Sodium induced embrittlement of 304L stainless steel
    Journal of Materials Research, 2018
    Co-Authors: Bassem Barkia, Thierry Auger, J. L. Courouau, J. Bourgon
    Abstract:

    The wettability of the 304L steel is an important parameter in Liquid Metal Embrittlement studies. Empirically, it is found to be greatly enhanced by pre-exposure to oxygenated Liquid Sodium. The corrosion interface formed during exposure to Sodium has been analyzed at the nanoscale by transmission electron microscopy using the focused ion beam sampling. A thin layer of Sodium chromite (Na xCrO2 with x ≤ 1) is detected at the interface validating wetting on an oxide mechanism for the enhanced wetting after pre-exposure. Fracture micromechanisms and the crack path of Liquid Sodium-embrittled austenitic steel 304L at 573 K have been investigated down to the nanoscale. High-resolution orientation mapping analyses immediately below the fracture surface show that abundant martensitic transformations (γ → α) and twinning occur during deformation of austenite. The preferential crack path is intergranular along the newly formed γ/γ interfaces. It is concluded that these transformations play a major role in the fracture process.

  • Investigation of crack propagation resistance of 304L, 316L and 316L(N) austenitic steels in Liquid Sodium
    Journal of Nuclear Materials, 2018
    Co-Authors: Bassem Barkia, J. L. Courouau, E Perrin, Veronique Lorentz, Matthieu Rivollier, Raphael Robin, Laetitia Nicolas, Celine Cabet, Thierry Auger
    Abstract:

    In order to assess the susceptibility of candidate structural materials to Liquid Metal Embrittlement (LME), the fracture behavior of three grades of austenitic steels was investigated in oxygenated (200 wppm) Liquid Sodium in the temperature range [473–673 K] on notched axisymmetric tensile specimens. The tests were carried out in an inert glove box at very low concentrations of dioxygen and humidity (

  • Multiscale investigation of crack path and microstructural changes during Liquid metal embrittlement of 304L austenitic steel in Liquid Sodium
    Corrosion Science, 2017
    Co-Authors: Bassem Barkia, Thierry Auger, J. L. Courouau, J. Bourgon
    Abstract:

    Abstract Fracture micro-mechanisms and crack path of embrittled austenitic steel 304L by Liquid Sodium strained at 4.2 × 10−7 m s−1 and 573 K are investigated underneath the fracture surface by transmission electron microscopy down to the nanoscale. Automated crystal orientation and phase mapping analyses show that abundant martensitic transformation (γ austenite → α’ martensite) as well as mechanical twinning occur during the deformation of austenite and play a major role in the fracture process. A correlation between the fracture surface features and the underlying microstructural interfaces is evidenced, strengthening the conclusion that Liquid metal embrittlement by Sodium of austenitic steels is basically an interfacial cracking phenomenon.

  • Liquid metal embrittlement of an austenitic stainless steel in Liquid Sodium
    Corrosion Science, 2014
    Co-Authors: S. Hémery, Thierry Auger, J. L. Courouau, F. Balbaud-célérier
    Abstract:

    Abstract A Fe18Cr9Ni1Mn austenitic stainless steel is shown to be sensitive to Liquid metal embrittlement in Liquid Sodium. Good wetting by Sodium is achieved during long-term pre-exposure before tensile testing in Liquid Sodium with additions of Na 2 O. Pre-exposure does not affect the normal ductile fracture mode of the steel in reference tests in the temperature range investigated ([473–673 K]). Intergranular cracking is found to play a key role in the fracture process in Liquid Sodium.

Akira Yamaguchi - One of the best experts on this subject based on the ideXlab platform.

  • thermal influence on steam generator heat transfer tube during Sodium water reaction accident of Sodium cooled fast reactor
    Nuclear Technology, 2009
    Co-Authors: Akira Yamaguchi, Takashi Takata, Hiroyuki Ohshima, Akikazu Kurihara
    Abstract:

    Sodium-water reaction is a design-basis accident of a Sodium fast reactor. A breach of the heat transfer tube in a steam generator (SG) results in contact of Liquid Sodium with water. The typical phenomenon is that the pressurized water blows off and is mixed with the Liquid Sodium surrounding SG tubes. The design and safety concern is a possibility of the secondary failure of nearby heat transfer tubes that could cause undesirable development of the accident. One needs to evaluate the temperature transients of the heat transfer tubes in the reaction region for safety evaluation. In the present study, a computational method is developed for this purpose. It solves the Sodium thermal hydraulics and the heat conduction in the adjacent heat transfer tubes. An experiment performed at the Japan Atomic Energy Agency is analyzed with the method developed in this study. It is found that analyzed temperatures are in good agreement with the experimental data. Based on the experimental and computational results, multiphase multicomponent flow characteristics are depicted. Furthermore, the heat transfer coefficient is evaluated using the instantaneous heat flux and temperature obtained from the numerical simulation.

  • computational methodology of Sodium water reaction phenomenon in steam generator of Sodium cooled fast reactor
    Journal of Nuclear Science and Technology, 2009
    Co-Authors: Takashi Takata, Akira Yamaguchi, Akihiro Uchibori, Hiroyuki Ohshima
    Abstract:

    A new computational methodology of Sodium-water reaction (SWR), which occurs in a steam generator of a Liquid-Sodium-cooled fast reactor when a heat transfer tube in the steam generator fails, has been developed considering multidimensional and multiphysics thermal hydraulics. Two kinds of reaction models are proposed in accordance with a phase of Sodium as a reactant. One is the surface reaction model in which water vapor reacts directly with Liquid Sodium at the interface between the Liquid Sodium and the water vapor. The reaction heat will lead to a vigorous evaporation of Liquid Sodium, resulting in a reaction of gas-phase Sodium. This is designated as the gas-phase reaction model. These two models are coupled with a multidimensional, multicomponent gas, and multiphase thermal hydraulics simulation method with compressibility (named the ‘SERAPHIM’ code). Using the present methodology, a numerical investigation of the SWR under a pin-bundle configuration (a benchmark analysis of the SWAT-1R experiment)...

  • numerical simulation of non premixed diffusion flame and reaction product aerosol behavior in Liquid metal pool combustion
    Journal of Nuclear Science and Technology, 2003
    Co-Authors: Akira Yamaguchi, Yuji Tajima
    Abstract:

    In the present study, a numerical methodology has been developed to solve a non-premixed diffusion flame under natural convection. The methodology has been applied to the calculation of the Liquid Sodium pool combustion experiment at various pool temperatures and oxygen molar fractions. The authors have proposed expressions of aerosol dynamics, radiation heat transfer and evaporation of Liquid Sodium that are applicable to Sodium combustion phenomena. The computations reproduce the experimental observations concerning burning rate, flame temperature and flame height, consistently. The aerosol release fractions are also in good agreement with the measurement. Dominant mechanisms of the mass and heat transfer are identified through the numerical simulation. An intrinsic feature found in the present study is that the Liquid Sodium pool combustion is self-limited and a negative feedback mechanism is at work. Interaction among the thermal-hydraulics, chemical reaction and aerosol dynamic behavior plays an important role in the phenomena and it has been successfully analyzed by the numerical simulation. The present method can be used to understand Sodium combustion phenomena and applied to the modeling of Sodium pool combustion for safety analyses of Liquid metal fast reactors. The numerical simulation is a useful tool because it can easily employ various conditions by changing parameters.

  • numerical simulation of non premixed diffusion flame and reaction product aerosol behavior in Liquid metal pool combustion
    Computational Technologies for Fluid Thermal Structural Chemical Systems With Industrial Applications Volume 1, 2002
    Co-Authors: Akira Yamaguchi, Yuji Tajima
    Abstract:

    A numerical methodology has been developed to solve a non-premixed diffusion flame under natural convection and applied to the calculation of the Liquid Sodium pool combustion experiment at various pool temperatures and oxygen concentrations. The computations reproduce the experimental observations concerning burning rate, flame temperature and flame height, consistently. The aerosol release rates are also in good agreement with the measurement. Dominant mechanisms of the mass and heat transfer are identified through the numerical simulation. An intrinsic feature is that the Liquid Sodium pool combustion is self-limited and negative feedback mechanism is at work Interaction among the thermal-hydraulics, chemical reaction and aerosol behavior plays an important role in the phenomena and it has been successfully analyzed by the numerical simulation. The present method can be used to understand Sodium combustion phenomena and applied to the modeling of Sodium pool combustion for safety analyses of Liquid metal fast reactors. The numerical simulation is a useful tool because it can easily employ various conditions by changing parameters.Copyright © 2002 by ASME

Bassem Barkia - One of the best experts on this subject based on the ideXlab platform.

  • investigation of crack propagation resistance of 304l 316l and 316l n austenitic steels in Liquid Sodium
    Journal of Nuclear Materials, 2018
    Co-Authors: Bassem Barkia, J. L. Courouau, E Perrin, Veronique Lorentz, Matthieu Rivollier, Raphael Robin, Laetitia Nicolas, Celine Cabet, T Auger
    Abstract:

    In order to assess the susceptibility of candidate structural materials to Liquid Metal Embrittlement (LME), the fracture behavior of three grades of austenitic steels was investigated in oxygenated (200 wppm) Liquid Sodium in the temperature range [473–673 K] on notched axisymmetric tensile specimens. The tests were carried out in an inert glove box at very low concentrations of dioxygen and humidity (<1 ppm) to prevent further contamination after pre-exposure in oxygenated Liquid Sodium. A decrease in crack propagation resistance of the three austenitic steels (304 L, 316 L(N), 316 L) is observed in oxygenated Liquid Sodium (200 wppm) from 573, 623 and 673 K respectively after pre-wetting in oxygenated Sodium. This reduction is correlated with a ductile to brittle change of the fracture surface. This effect observed with the three austenitic steels is attributed to the onset of LME after significant plastic deformation.

  • Wetting by Liquid Sodium and fracture path analysis of Sodium induced embrittlement of 304L stainless steel
    Journal of Materials Research, 2018
    Co-Authors: Bassem Barkia, Thierry Auger, J. L. Courouau, J. Bourgon
    Abstract:

    The wettability of the 304L steel is an important parameter in Liquid Metal Embrittlement studies. Empirically, it is found to be greatly enhanced by pre-exposure to oxygenated Liquid Sodium. The corrosion interface formed during exposure to Sodium has been analyzed at the nanoscale by transmission electron microscopy using the focused ion beam sampling. A thin layer of Sodium chromite (Na xCrO2 with x ≤ 1) is detected at the interface validating wetting on an oxide mechanism for the enhanced wetting after pre-exposure. Fracture micromechanisms and the crack path of Liquid Sodium-embrittled austenitic steel 304L at 573 K have been investigated down to the nanoscale. High-resolution orientation mapping analyses immediately below the fracture surface show that abundant martensitic transformations (γ → α) and twinning occur during deformation of austenite. The preferential crack path is intergranular along the newly formed γ/γ interfaces. It is concluded that these transformations play a major role in the fracture process.

  • Investigation of crack propagation resistance of 304L, 316L and 316L(N) austenitic steels in Liquid Sodium
    Journal of Nuclear Materials, 2018
    Co-Authors: Bassem Barkia, J. L. Courouau, E Perrin, Veronique Lorentz, Matthieu Rivollier, Raphael Robin, Laetitia Nicolas, Celine Cabet, Thierry Auger
    Abstract:

    In order to assess the susceptibility of candidate structural materials to Liquid Metal Embrittlement (LME), the fracture behavior of three grades of austenitic steels was investigated in oxygenated (200 wppm) Liquid Sodium in the temperature range [473–673 K] on notched axisymmetric tensile specimens. The tests were carried out in an inert glove box at very low concentrations of dioxygen and humidity (

  • Multiscale investigation of crack path and microstructural changes during Liquid metal embrittlement of 304L austenitic steel in Liquid Sodium
    Corrosion Science, 2017
    Co-Authors: Bassem Barkia, Thierry Auger, J. L. Courouau, J. Bourgon
    Abstract:

    Abstract Fracture micro-mechanisms and crack path of embrittled austenitic steel 304L by Liquid Sodium strained at 4.2 × 10−7 m s−1 and 573 K are investigated underneath the fracture surface by transmission electron microscopy down to the nanoscale. Automated crystal orientation and phase mapping analyses show that abundant martensitic transformation (γ austenite → α’ martensite) as well as mechanical twinning occur during the deformation of austenite and play a major role in the fracture process. A correlation between the fracture surface features and the underlying microstructural interfaces is evidenced, strengthening the conclusion that Liquid metal embrittlement by Sodium of austenitic steels is basically an interfacial cracking phenomenon.