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Hadi Savaloni - One of the best experts on this subject based on the ideXlab platform.
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A study of the corrosion of Stainless Steel 304L coated with a 190 nm-thick manganese layer and annealed with nitrogen flux in a 0.4-mole solution of H_2SO_4 at different temperatures
Journal of Theoretical and Applied Physics, 2019Co-Authors: Farzaneh Modiri, Hadi SavaloniAbstract:A method for enhancing the resistance against corrosion of Stainless Steel 304L coated with 190 nm-thick manganese film and annealed with nitrogen flux at constant temperature (723 K) is reported. The variable quantity in this work is the temperature of the corroding solution (293 K and 333 K). X-ray diffraction analysis was employed to investigate the crystallographical changes of the annealed samples; atomic force microscope and scanning electron microscope were used for the morphology and studying the roughness of their surfaces; polarization analysis, electrochemical impedance spectroscopy, and phase and Bode diagrams, as well as the Kramers–Kronig transformation, were employed to study the susceptibility of the samples to corrosion, at temperatures 293 K and 333 K in 0.4 M H_2SO_4 solutions. Our results, from all the above analyses, unanimously point to the fact that in the process of enhancing resistance to corrosion, the annealing stage is the most crucial for improving the coating and the crystal structure of the samples and that the adsorption of Mn is not sufficient for the enhancement of the surface layer. Moreover, it was observed that increasing the temperature of the solution decreases the resistance of the samples owing to an increase in the rate of corrosion.
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A study of the corrosion of Stainless Steel 304L coated with a 190 nm-thick manganese layer and annealed with nitrogen flux in a 0.4-mole solution of H 2 SO 4 at different temperatures
journal of theoretical and applied physics, 2019Co-Authors: Farzaneh Modiri, Hadi SavaloniAbstract:A method for enhancing the resistance against corrosion of Stainless Steel 304L coated with 190 nm-thick manganese film and annealed with nitrogen flux at constant temperature (723 K) is reported. The variable quantity in this work is the temperature of the corroding solution (293 K and 333 K). X-ray diffraction analysis was employed to investigate the crystallographical changes of the annealed samples; atomic force microscope and scanning electron microscope were used for the morphology and studying the roughness of their surfaces; polarization analysis, electrochemical impedance spectroscopy, and phase and Bode diagrams, as well as the Kramers–Kronig transformation, were employed to study the susceptibility of the samples to corrosion, at temperatures 293 K and 333 K in 0.4 M H2SO4 solutions. Our results, from all the above analyses, unanimously point to the fact that in the process of enhancing resistance to corrosion, the annealing stage is the most crucial for improving the coating and the crystal structure of the samples and that the adsorption of Mn is not sufficient for the enhancement of the surface layer. Moreover, it was observed that increasing the temperature of the solution decreases the resistance of the samples owing to an increase in the rate of corrosion.
F. Hodaj - One of the best experts on this subject based on the ideXlab platform.
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Effect of Isothermal Hold on the Microstructural Evolution of the Stainless Steel 304L/Zircaloy-4 Interface
Journal of Materials Engineering and Performance, 2017Co-Authors: A. Lebaili, M. Taouinet, D. Nibou, S. Lebaili, F. HodajAbstract:The transition from solid-state bonding of the Stainless Steel 304L/Zircaloy-4 diffusion couple to a partial liquid-phase bonding is important for the bonding process at temperatures ranging from 950 to 1050 °C. In this study, the temperature at which a melting process occurs at the interface after 45 min of isothermal holdings is determined experimentally. This melting process leads to a drastic change in the thickness of the reaction products zone (RPZ) as well as on its microstructure. Diffusion couples were characterized by SEM-EDS, and quantitative chemical analyses of different phases are performed by EPMA. The RPZ consists of three layers: the (α-Fe-Cr) phase layer and two layers consisting of Zr(Fe,Cr)_2 (ε), Zr_2(Fe,Ni) and (α-Zr) phases. The thickness of these layers strongly depends on the holding temperature. The analysis allowed the description of the physicochemical phenomena occurring during isothermal holding as well as during cooling. The solidification paths are determined at 1000, 1020 and 1050 °C. Hardness tests are performed on the bonded samples in order to qualify the mechanical properties of different phases of the RPZ. This study leads to a better understanding of the complex phenomena intervening in the joining process which is very useful for applications in industrial scale.
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effect of isothermal hold on the microstructural evolution of the Stainless Steel 304L zircaloy 4 interface
Journal of Materials Engineering and Performance, 2017Co-Authors: A. Lebaili, M. Taouinet, D. Nibou, S. Lebaili, F. HodajAbstract:The transition from solid-state bonding of the Stainless Steel 304L/Zircaloy-4 diffusion couple to a partial liquid-phase bonding is important for the bonding process at temperatures ranging from 950 to 1050 °C. In this study, the temperature at which a melting process occurs at the interface after 45 min of isothermal holdings is determined experimentally. This melting process leads to a drastic change in the thickness of the reaction products zone (RPZ) as well as on its microstructure. Diffusion couples were characterized by SEM-EDS, and quantitative chemical analyses of different phases are performed by EPMA. The RPZ consists of three layers: the (α-Fe-Cr) phase layer and two layers consisting of Zr(Fe,Cr)2 (e), Zr2(Fe,Ni) and (α-Zr) phases. The thickness of these layers strongly depends on the holding temperature. The analysis allowed the description of the physicochemical phenomena occurring during isothermal holding as well as during cooling. The solidification paths are determined at 1000, 1020 and 1050 °C. Hardness tests are performed on the bonded samples in order to qualify the mechanical properties of different phases of the RPZ. This study leads to a better understanding of the complex phenomena intervening in the joining process which is very useful for applications in industrial scale.
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Effect of Isothermal Hold on the Microstructural Evolution of the Stainless Steel 304L/Zircaloy-4 Interface
Journal of Materials Engineering and Performance, 2017Co-Authors: A. Lebaili, M. Taouinet, D. Nibou, S. Lebaili, F. HodajAbstract:The transition from solid-state bonding of the Stainless Steel 304L/Zircaloy-4 diffusion couple to a partial liquid-phase bonding is important for the bonding process at temperatures ranging from 950 to 1050 °C. In this study, the temperature at which a melting process occurs at the interface after 45 min of isothermal holdings is determined experimentally. This melting process leads to a drastic change in the thickness of the reaction products zone (RPZ) as well as on its microstructure. Diffusion couples were characterized by SEM-EDS, and quantitative chemical analyses of different phases are performed by EPMA. The RPZ consists of three layers: the (α-Fe-Cr) phase layer and two layers consisting of Zr(Fe,Cr)2 (e), Zr2(Fe,Ni) and (α-Zr) phases. The thickness of these layers strongly depends on the holding temperature. The analysis allowed the description of the physicochemical phenomena occurring during isothermal holding as well as during cooling. The solidification paths are determined at 1000, 1020 and 1050 °C. Hardness tests are performed on the bonded samples in order to qualify the mechanical properties of different phases of the RPZ. This study leads to a better understanding of the complex phenomena intervening in the joining process which is very useful for applications in industrial scale.
David P Adams - One of the best experts on this subject based on the ideXlab platform.
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in situ neutron diffraction study of the influence of microstructure on the mechanical response of additively manufactured 304L Stainless Steel
Metallurgical and Materials Transactions A-physical Metallurgy and Materials Science, 2017Co-Authors: D W Brown, David P Adams, John S. Carpenter, Levente Balogh, Bjorn Clausen, Graham King, Benjamin Reedlunn, T A Palmer, Michael Christopher Maguire, Sven C VogelAbstract:In situ neutron diffraction measurements were completed during tensile and compressive deformation of Stainless Steel 304L additively manufactured (AM) using a high power directed energy deposition process. Traditionally produced wrought 304L material was also studied for comparison. The AM material exhibited roughly 200 MPa higher flow stress relative to the wrought material. Crystallite size, crystallographic texture, dislocation density, and lattice strains were all characterized to understand the differences in the macroscopic mechanical behavior. The AM material’s initial dislocation density was about 10 times that of the wrought material, and the flow strength of both materials obeyed the Taylor equation, indicating that the AM material’s increased yield strength was primarily due to greater dislocation density. Also, a ~50 MPa flow strength tension/compression asymmetry was observed in the AM material, and several potential causes were examined.
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mechanical and electromechanical behavior of oxide coatings grown on Stainless Steel 304L by nanosecond pulsed laser irradiation
Surface & Coatings Technology, 2013Co-Authors: Samantha K Lawrence, David P Adams, David F Bahr, N R MoodyAbstract:Abstract Nanosecond-pulsed laser exposure of an austenitic Stainless Steel 304L in ambient atmosphere produces dielectric oxide coatings with characteristic colors. From an industrial perspective, these oxide layers are particularly interesting for use as unique authenticity identifiers on welded or sealed components. Processing parameters control oxide thickness and residual stresses. The combined properties of the oxide–substrate system control deformation, fracture, and electromechanical behavior. Instrumented nanoindentation indicates that oxide mechanical properties are dictated by film thickness. While elastic modulus is relatively insensitive to laser processing conditions and has an average value of ~ 150 GPa, hardness decreases sharply as film thickness decreases below 100 nm. Indentation coupled with electron microscopy as well as conducting nanoindentation suggest that both fracture behavior and electromechanical response are a function of laser processing; thick oxides fracture circumferentially upon indentation while thin oxides undergo radial cracking and thinner laser oxides are typically more conductive than their thicker counterparts.
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nanosecond pulsed laser irradiation of Stainless Steel 304L oxide growth and effects on underlying metal
Surface & Coatings Technology, 2013Co-Authors: David P Adams, V C Hodges, Deidre A Hirschfeld, Mark A Rodriguez, J P Mcdonald, Paul Gabriel KotulaAbstract:Abstract Nanosecond-pulsed, infrared (1064 nm) laser irradiation was used to create metal oxide coatings on the surface of polished Stainless Steel 304L austenite for application as color markings and unique tags/identifiers. By rastering a Gaussian-shaped, focused laser beam across a specimen in air, continuous metal oxide coatings were grown to thicknesses in the range of 20 to ~ 500 nm. Oxide coating thickness generally increased with laser fluence. However, for large accumulated fluences in excess of ~ 600–800 J/cm2, oxide growth was affected by evaporation and particle ejection resulting in a decreased coating thickness. Transmission electron microscopy and X-ray diffraction revealed that oxide coatings developed a polycrystalline, spinel structure having a lattice constant = 8.4 A (consistent with MnCr2O4 and Fe3O4). Pulsed laser irradiation and oxide growth modified the composition of Stainless Steel substrates by reducing the Cr and Mn concentration within the melt zone. The reflectance and chromaticity of laser-fabricated oxide coatings were characterized using spectrophotometry. These optical properties are described in the context of measured oxide thicknesses.
Farzaneh Modiri - One of the best experts on this subject based on the ideXlab platform.
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A study of the corrosion of Stainless Steel 304L coated with a 190 nm-thick manganese layer and annealed with nitrogen flux in a 0.4-mole solution of H_2SO_4 at different temperatures
Journal of Theoretical and Applied Physics, 2019Co-Authors: Farzaneh Modiri, Hadi SavaloniAbstract:A method for enhancing the resistance against corrosion of Stainless Steel 304L coated with 190 nm-thick manganese film and annealed with nitrogen flux at constant temperature (723 K) is reported. The variable quantity in this work is the temperature of the corroding solution (293 K and 333 K). X-ray diffraction analysis was employed to investigate the crystallographical changes of the annealed samples; atomic force microscope and scanning electron microscope were used for the morphology and studying the roughness of their surfaces; polarization analysis, electrochemical impedance spectroscopy, and phase and Bode diagrams, as well as the Kramers–Kronig transformation, were employed to study the susceptibility of the samples to corrosion, at temperatures 293 K and 333 K in 0.4 M H_2SO_4 solutions. Our results, from all the above analyses, unanimously point to the fact that in the process of enhancing resistance to corrosion, the annealing stage is the most crucial for improving the coating and the crystal structure of the samples and that the adsorption of Mn is not sufficient for the enhancement of the surface layer. Moreover, it was observed that increasing the temperature of the solution decreases the resistance of the samples owing to an increase in the rate of corrosion.
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A study of the corrosion of Stainless Steel 304L coated with a 190 nm-thick manganese layer and annealed with nitrogen flux in a 0.4-mole solution of H 2 SO 4 at different temperatures
journal of theoretical and applied physics, 2019Co-Authors: Farzaneh Modiri, Hadi SavaloniAbstract:A method for enhancing the resistance against corrosion of Stainless Steel 304L coated with 190 nm-thick manganese film and annealed with nitrogen flux at constant temperature (723 K) is reported. The variable quantity in this work is the temperature of the corroding solution (293 K and 333 K). X-ray diffraction analysis was employed to investigate the crystallographical changes of the annealed samples; atomic force microscope and scanning electron microscope were used for the morphology and studying the roughness of their surfaces; polarization analysis, electrochemical impedance spectroscopy, and phase and Bode diagrams, as well as the Kramers–Kronig transformation, were employed to study the susceptibility of the samples to corrosion, at temperatures 293 K and 333 K in 0.4 M H2SO4 solutions. Our results, from all the above analyses, unanimously point to the fact that in the process of enhancing resistance to corrosion, the annealing stage is the most crucial for improving the coating and the crystal structure of the samples and that the adsorption of Mn is not sufficient for the enhancement of the surface layer. Moreover, it was observed that increasing the temperature of the solution decreases the resistance of the samples owing to an increase in the rate of corrosion.
A. Lebaili - One of the best experts on this subject based on the ideXlab platform.
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Effect of Isothermal Hold on the Microstructural Evolution of the Stainless Steel 304L/Zircaloy-4 Interface
Journal of Materials Engineering and Performance, 2017Co-Authors: A. Lebaili, M. Taouinet, D. Nibou, S. Lebaili, F. HodajAbstract:The transition from solid-state bonding of the Stainless Steel 304L/Zircaloy-4 diffusion couple to a partial liquid-phase bonding is important for the bonding process at temperatures ranging from 950 to 1050 °C. In this study, the temperature at which a melting process occurs at the interface after 45 min of isothermal holdings is determined experimentally. This melting process leads to a drastic change in the thickness of the reaction products zone (RPZ) as well as on its microstructure. Diffusion couples were characterized by SEM-EDS, and quantitative chemical analyses of different phases are performed by EPMA. The RPZ consists of three layers: the (α-Fe-Cr) phase layer and two layers consisting of Zr(Fe,Cr)_2 (ε), Zr_2(Fe,Ni) and (α-Zr) phases. The thickness of these layers strongly depends on the holding temperature. The analysis allowed the description of the physicochemical phenomena occurring during isothermal holding as well as during cooling. The solidification paths are determined at 1000, 1020 and 1050 °C. Hardness tests are performed on the bonded samples in order to qualify the mechanical properties of different phases of the RPZ. This study leads to a better understanding of the complex phenomena intervening in the joining process which is very useful for applications in industrial scale.
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effect of isothermal hold on the microstructural evolution of the Stainless Steel 304L zircaloy 4 interface
Journal of Materials Engineering and Performance, 2017Co-Authors: A. Lebaili, M. Taouinet, D. Nibou, S. Lebaili, F. HodajAbstract:The transition from solid-state bonding of the Stainless Steel 304L/Zircaloy-4 diffusion couple to a partial liquid-phase bonding is important for the bonding process at temperatures ranging from 950 to 1050 °C. In this study, the temperature at which a melting process occurs at the interface after 45 min of isothermal holdings is determined experimentally. This melting process leads to a drastic change in the thickness of the reaction products zone (RPZ) as well as on its microstructure. Diffusion couples were characterized by SEM-EDS, and quantitative chemical analyses of different phases are performed by EPMA. The RPZ consists of three layers: the (α-Fe-Cr) phase layer and two layers consisting of Zr(Fe,Cr)2 (e), Zr2(Fe,Ni) and (α-Zr) phases. The thickness of these layers strongly depends on the holding temperature. The analysis allowed the description of the physicochemical phenomena occurring during isothermal holding as well as during cooling. The solidification paths are determined at 1000, 1020 and 1050 °C. Hardness tests are performed on the bonded samples in order to qualify the mechanical properties of different phases of the RPZ. This study leads to a better understanding of the complex phenomena intervening in the joining process which is very useful for applications in industrial scale.
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Effect of Isothermal Hold on the Microstructural Evolution of the Stainless Steel 304L/Zircaloy-4 Interface
Journal of Materials Engineering and Performance, 2017Co-Authors: A. Lebaili, M. Taouinet, D. Nibou, S. Lebaili, F. HodajAbstract:The transition from solid-state bonding of the Stainless Steel 304L/Zircaloy-4 diffusion couple to a partial liquid-phase bonding is important for the bonding process at temperatures ranging from 950 to 1050 °C. In this study, the temperature at which a melting process occurs at the interface after 45 min of isothermal holdings is determined experimentally. This melting process leads to a drastic change in the thickness of the reaction products zone (RPZ) as well as on its microstructure. Diffusion couples were characterized by SEM-EDS, and quantitative chemical analyses of different phases are performed by EPMA. The RPZ consists of three layers: the (α-Fe-Cr) phase layer and two layers consisting of Zr(Fe,Cr)2 (e), Zr2(Fe,Ni) and (α-Zr) phases. The thickness of these layers strongly depends on the holding temperature. The analysis allowed the description of the physicochemical phenomena occurring during isothermal holding as well as during cooling. The solidification paths are determined at 1000, 1020 and 1050 °C. Hardness tests are performed on the bonded samples in order to qualify the mechanical properties of different phases of the RPZ. This study leads to a better understanding of the complex phenomena intervening in the joining process which is very useful for applications in industrial scale.