The Experts below are selected from a list of 8073 Experts worldwide ranked by ideXlab platform
Dagoberto Brandao Santos - One of the best experts on this subject based on the ideXlab platform.
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development of an ultrafine grained ferrite in a low c mn and nb ti microalloyed Steels after warm torsion and intercritical annealing
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005Co-Authors: Giovane M Azevedo, Rinaldo Barbosa, Elena V Pereloma, Dagoberto Brandao SantosAbstract:Abstract In recent years, several studies on grain refinement of ferrite have been conducted by different methods (equal channel angular pressing (ECAP), high pressure torsion (HPT), accumulative roll bonding (ARB)) in order to optimize the relationship between mechanical properties and microstructure of Steels. The present work deals with the strain-induced dynamic transformation of ferrite. Samples of low C–Mn and Nb–Ti microalloyed Steels were intensively deformed in warm torsion. This resulted in the formation of ultrafine ferrite grains (∼1 μm) thereby enhancing the mechanical properties compared to the ordinary hot rolled products without the necessity of implementing an extremely high strain accumulation. The following annealing has resulted in recrystallization and growth of ferrite grains accompanied by a homogenization of the final microstructure and a decrease in hardness. With increase in annealing time the volume fraction of martensite/austenite (MA) constituent increased. The results have shown that the effect of Steel Chemistry was insignificant in comparison with the effect of thermomechanical processing parameters.
S Yue - One of the best experts on this subject based on the ideXlab platform.
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a fast fracture approach to assess hydrogen embrittlement he susceptibility and mechanism s of high strength martensitic Steels
Corrosion Science, 2021Co-Authors: Tuhin Das, S Brahimi, Jun Song, S YueAbstract:Abstract A newly proposed rapid fracture test in four-point bending was used to test two different combinations of three quench and tempered Steels, having: (a) similar strength levels with different Steel chemistries, (b) different strength levels with same Steel Chemistry, with and without pre-charging of hydrogen. The test results show significant differences in HE susceptibility among the materials in both cases. The essential fractographic features pertinent to the HE failure of martensitic Steels remain evident, despite fast loading. The study establishes the potential of the HE test in assessing susceptibility, further indicating significant influences of local plasticity and micromechanics on HE.
Olivier Bouaziz - One of the best experts on this subject based on the ideXlab platform.
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Predicting the stress-strain behaviour of carbon Steels under hot working conditions:An irreversible thermodynamics model
Scripta Materialia, 2009Co-Authors: Mingxin Huang, Astrid Perlade, Pedro E.j. Rivera-díaz-del-castillo, Olivier BouazizAbstract:An irreversible thermodynamics treatment of plastic deformation is re-formulated to include the effects of Steel Chemistry in austenite hot rolling. By relating the entropy to the relevant fluxes and forces, the assumption dS ∝ d τ / T is removed, where S and τ are the entropy and stress at temperature T . The effect of composition is incorporated in the activation energy for cross-slip, obtaining a good description of the stress–strain behaviour of various grades as a function of temperature and strain rate.
Giovane M Azevedo - One of the best experts on this subject based on the ideXlab platform.
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development of an ultrafine grained ferrite in a low c mn and nb ti microalloyed Steels after warm torsion and intercritical annealing
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005Co-Authors: Giovane M Azevedo, Rinaldo Barbosa, Elena V Pereloma, Dagoberto Brandao SantosAbstract:Abstract In recent years, several studies on grain refinement of ferrite have been conducted by different methods (equal channel angular pressing (ECAP), high pressure torsion (HPT), accumulative roll bonding (ARB)) in order to optimize the relationship between mechanical properties and microstructure of Steels. The present work deals with the strain-induced dynamic transformation of ferrite. Samples of low C–Mn and Nb–Ti microalloyed Steels were intensively deformed in warm torsion. This resulted in the formation of ultrafine ferrite grains (∼1 μm) thereby enhancing the mechanical properties compared to the ordinary hot rolled products without the necessity of implementing an extremely high strain accumulation. The following annealing has resulted in recrystallization and growth of ferrite grains accompanied by a homogenization of the final microstructure and a decrease in hardness. With increase in annealing time the volume fraction of martensite/austenite (MA) constituent increased. The results have shown that the effect of Steel Chemistry was insignificant in comparison with the effect of thermomechanical processing parameters.
Tuhin Das - One of the best experts on this subject based on the ideXlab platform.
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a fast fracture approach to assess hydrogen embrittlement he susceptibility and mechanism s of high strength martensitic Steels
Corrosion Science, 2021Co-Authors: Tuhin Das, S Brahimi, Jun Song, S YueAbstract:Abstract A newly proposed rapid fracture test in four-point bending was used to test two different combinations of three quench and tempered Steels, having: (a) similar strength levels with different Steel chemistries, (b) different strength levels with same Steel Chemistry, with and without pre-charging of hydrogen. The test results show significant differences in HE susceptibility among the materials in both cases. The essential fractographic features pertinent to the HE failure of martensitic Steels remain evident, despite fast loading. The study establishes the potential of the HE test in assessing susceptibility, further indicating significant influences of local plasticity and micromechanics on HE.
