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W G Zhang - One of the best experts on this subject based on the ideXlab platform.
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The Effects of Stress State on the Strain Hardening Behaviors of TWIP Steel
Journal of Materials Engineering and Performance, 2017Co-Authors: Liu Fei, Wenjiao Dan, W G ZhangAbstract:Twinning-Induced Plasticity (TWIP) Steels have received great attention due to their excellent mechanical properties as a result of austenite twinning during straining. In this paper, the effects of stress state on the strain hardening behaviors of Fe-20Mn-1.2C TWIP Steel were studied. A twinning model considering stress state was presented based on the shear-band framework, and a strain hardening model was proposed by taking dislocation mixture evolution into account. The models were verified by the experimental results of uniaxial tension, simple shear and rolling processes. The strain hardening behaviors of TWIP Steel under different stress states were predicted. The results show that the stress state can improve the austenite twining and benefit the strain hardening of TWIP Steel.
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Strain hardening behavior of TWIP Steel in plastic deformation with temperature
Modelling and Simulation in Materials Science and Engineering, 2015Co-Authors: Wenjiao Dan, F Liu, W G ZhangAbstract:Considering dynamic recovery/recrystallization and twinning effects, in this paper we develop a dislocation-based model to study the strain hardening behavior of TWIP Steel. In the model, the dislocation evolution is controlled through a dynamic recovery/recrystallization process at high temperatures, and is primarily dominated by a twinning-induced plasticity (TWIP) process at moderate/ambient temperatures. The corresponding dislocation evolution model is established based on irreversible thermodynamics at high temperatures and conventional plasticity theory at moderate/ambient temperatures, respectively. A factor of δ is introduced to reflect the mixture effect of dynamic recovery/recrystallization and twinning on dislocation evolution, and δ increases with deformation temperature. The stress–strain response and strain hardening behavior of TWIP Steel (Fe–22Mn–0.6C) are validated at 293, 473, 573, 673, 773 and 873 K. Moreover, the mixture influence of dynamic recovery/recrystallization and twinning on the strain hardening behavior of TWIP Steel is analyzed at 293, 473 and 573 K.
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Mechanical behavior prediction of TWIP Steel in plastic deformation
Computational Materials Science, 2014Co-Authors: Wenjiao Dan, Liu Fei, W G ZhangAbstract:Abstract This study aims to predict the influence of twinning volume fraction and grain size on the mechanical behavior of TWIP Steel in plastic deformation with a dislocation-based model considering austenite twinning. The preceding model was implemented into FEM codes based on the conventional elastoplasticity increment theory, and verified by the experimental data of Allain et al. (2002). Then the influence of twinning volume fraction and grain size on the work-hardening of TWIP Steel in tensile deformation was investigated. A damage factor was proposed to evaluate the failure trend in plastic deformation based on the Freudenthal fracture criterion, and the effect of twinning volume fraction and grain size on the proposed factor was analyzed. The results indicate that higher twinning volume fraction improves strength and ductility, delays the failure of TWIP Steel. However, finer grain improves strength and ductility, but may deteriorate fracture resistance of TWIP Steel.
P Cugy - One of the best experts on this subject based on the ideXlab platform.
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damage observation in a high manganese austenitic TWIP Steel by synchrotron radiation computed tomography
Scripta Materialia, 2010Co-Authors: J Lorthios, Franck Nguyen, Annefrancoise Gourgues, Thilo F Morgeneyer, P CugyAbstract:Internal damage below the fracture surface of a multiaxial specimen made of twinning-induced plasticity (TWIP) Steel was observed by three-dimensional X-ray microtomography as very elongated “primary” voids. Specific tools for the local damage analysis were developed. A gradient in void volume fraction was measured from the fracture surface down to the bulk of the scanned volume (from ∼0.06% to 90% in area fraction), indicating strongly localized final fracture.
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Damage observation in a high-manganese austenitic TWIP Steel by synchrotron radiation computed tomography
Scripta Materialia, 2010Co-Authors: J Lorthios, Thilo F Morgeneyer, Franck N'guyen, Anne-françoise Gourgues-lorenzon, P CugyAbstract:Internal damage below the fracture surface of a multiaxial specimen made of twinning-induced plasticity (TWIP) Steel was observed by three-dimensional X-ray microtomography as very elongated “primary” voids. Specific tools for the local damage analysis were developed. A gradient in void volume fraction was measured from the fracture surface down to the bulk of the scanned volume (from not, vert, similar0.06% to 90% in area fraction), indicating strongly localized final fracture.
J Lorthios - One of the best experts on this subject based on the ideXlab platform.
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Fracture behaviour of a Fe–22Mn–0.6C–0.2V austenitic TWIP Steel
International Journal of Mechanical Sciences, 2015Co-Authors: J Lorthios, Matthieu Mazière, Xavier Lemoine, Philippe Cugy, Jacques Besson, Anne-françoise Gourgues-lorenzonAbstract:The mechanical behaviour of a 22Mn-0.6C-0.2V austenitic TWIP Steel has been extensively characterised for a variety of strain ratios (from shear to biaxial stretching) using smooth and notched specimens. A constitutive model involving a non-isotropic yield function together with isotropic and/or kinematic hardening satisfactorily represented the experimental database. It was used to estimate local stress and strain fields and to derive a fracture criterion based on the equivalent stress and Lode angle that were expressed to be consistent with the constitutive equations describing the plastic flow behaviour. A weak dependence on hydrostatic stress further improves prediction of fracture initiation, with an average standard error of less than 5% over ten different mechanical tests.
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damage observation in a high manganese austenitic TWIP Steel by synchrotron radiation computed tomography
Scripta Materialia, 2010Co-Authors: J Lorthios, Franck Nguyen, Annefrancoise Gourgues, Thilo F Morgeneyer, P CugyAbstract:Internal damage below the fracture surface of a multiaxial specimen made of twinning-induced plasticity (TWIP) Steel was observed by three-dimensional X-ray microtomography as very elongated “primary” voids. Specific tools for the local damage analysis were developed. A gradient in void volume fraction was measured from the fracture surface down to the bulk of the scanned volume (from ∼0.06% to 90% in area fraction), indicating strongly localized final fracture.
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Damage observation in a high-manganese austenitic TWIP Steel by synchrotron radiation computed tomography
Scripta Materialia, 2010Co-Authors: J Lorthios, Thilo F Morgeneyer, Franck N'guyen, Anne-françoise Gourgues-lorenzon, P CugyAbstract:Internal damage below the fracture surface of a multiaxial specimen made of twinning-induced plasticity (TWIP) Steel was observed by three-dimensional X-ray microtomography as very elongated “primary” voids. Specific tools for the local damage analysis were developed. A gradient in void volume fraction was measured from the fracture surface down to the bulk of the scanned volume (from not, vert, similar0.06% to 90% in area fraction), indicating strongly localized final fracture.
Rintaro Ueji - One of the best experts on this subject based on the ideXlab platform.
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flow stress analysis of TWIP Steel via the xrd measurement of dislocation density
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2010Co-Authors: Ghasem Dini, Rintaro Ueji, A Najafizadeh, S M MonirvaghefiAbstract:Abstract In this study, the rate of dislocation accumulation in the tensile strained twinning induced plasticity (TWIP) Steel was calculated via the X-ray diffraction (XRD) measurements and compared with other fcc metals and alloys. The results indicated that the XRD technique is an alternative method to estimate the dislocation density. Moreover, flow stress analysis of Fe–31Mn–3Al–3Si TWIP Steel with the grain size of about 18 μm indicated that, beside a direct effect of the dislocation interactions on the flow stress, another strengthening mechanism is also required to describe the flow behavior. For this reason, the strengthening contribution due to the formation of mechanical twins was considered as a reduction of dislocation mean free path. Interestingly, the estimated flow stress equation consisting of the strengthening effects of both dislocation interactions and dynamic microstructure refinement due to mechanical twinning (i.e., the dynamic Hall–Petch effect) are in good agreement with the experimental data and equation proposed by Ludwigson for low SFE materials.
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Improved tensile properties of partially recrystallized submicron grained TWIP Steel
Materials Letters, 2010Co-Authors: Ghasem Dini, Abbas Najafizadeh, Rintaro Ueji, S.m. Monir-vaghefiAbstract:The effects of cold rolling reduction and annealing temperature on the mechanical properties of twinning induced plasticity (TWIP) Steel have been investigated. The results indicated that the strengthening effect of unrecrystallized areas with a high density of nano-scale mechanical twins increased with increasing cold rolling reduction. In addition, the ductility also increased with increasing annealing temperature. Therefore, utilization of large cold rolling reduction and subsequently annealing treatment in the partial recrystallization region was suggested as an effective method to obtain submicron grained TWIP Steel with an excellent combination of strength and ductility.
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High Speed Deformation of Ultrafine Grained TWIP Steel
Materials Science Forum, 2007Co-Authors: Rintaro Ueji, Kenji Harada, Noriyuki Tsuchida, Kazutoshi KunishigeAbstract:Tensile properties of twinning induced plasticity (TWIP) Steels (31%Mn-3%Al-3%Si-Fe) with various mean grain sizes ranging from ultrafine grain size (1.1μm) to conventional one (35.5μm) at a wide range of strain rates from 10-3sec-1 to 103sec-1 were studied. The ultrafine grained TWIP Steel exhibits a large work hardening and keeps an adequate elongation at any strain rate. The strength held to the Hall-Petch relationship at each strain rate and the Hall-Petch slopes do not change largely.
Wenjiao Dan - One of the best experts on this subject based on the ideXlab platform.
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The Effects of Stress State on the Strain Hardening Behaviors of TWIP Steel
Journal of Materials Engineering and Performance, 2017Co-Authors: Liu Fei, Wenjiao Dan, W G ZhangAbstract:Twinning-Induced Plasticity (TWIP) Steels have received great attention due to their excellent mechanical properties as a result of austenite twinning during straining. In this paper, the effects of stress state on the strain hardening behaviors of Fe-20Mn-1.2C TWIP Steel were studied. A twinning model considering stress state was presented based on the shear-band framework, and a strain hardening model was proposed by taking dislocation mixture evolution into account. The models were verified by the experimental results of uniaxial tension, simple shear and rolling processes. The strain hardening behaviors of TWIP Steel under different stress states were predicted. The results show that the stress state can improve the austenite twining and benefit the strain hardening of TWIP Steel.
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Strain hardening behavior of TWIP Steel in plastic deformation with temperature
Modelling and Simulation in Materials Science and Engineering, 2015Co-Authors: Wenjiao Dan, F Liu, W G ZhangAbstract:Considering dynamic recovery/recrystallization and twinning effects, in this paper we develop a dislocation-based model to study the strain hardening behavior of TWIP Steel. In the model, the dislocation evolution is controlled through a dynamic recovery/recrystallization process at high temperatures, and is primarily dominated by a twinning-induced plasticity (TWIP) process at moderate/ambient temperatures. The corresponding dislocation evolution model is established based on irreversible thermodynamics at high temperatures and conventional plasticity theory at moderate/ambient temperatures, respectively. A factor of δ is introduced to reflect the mixture effect of dynamic recovery/recrystallization and twinning on dislocation evolution, and δ increases with deformation temperature. The stress–strain response and strain hardening behavior of TWIP Steel (Fe–22Mn–0.6C) are validated at 293, 473, 573, 673, 773 and 873 K. Moreover, the mixture influence of dynamic recovery/recrystallization and twinning on the strain hardening behavior of TWIP Steel is analyzed at 293, 473 and 573 K.
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Mechanical behavior prediction of TWIP Steel in plastic deformation
Computational Materials Science, 2014Co-Authors: Wenjiao Dan, Liu Fei, W G ZhangAbstract:Abstract This study aims to predict the influence of twinning volume fraction and grain size on the mechanical behavior of TWIP Steel in plastic deformation with a dislocation-based model considering austenite twinning. The preceding model was implemented into FEM codes based on the conventional elastoplasticity increment theory, and verified by the experimental data of Allain et al. (2002). Then the influence of twinning volume fraction and grain size on the work-hardening of TWIP Steel in tensile deformation was investigated. A damage factor was proposed to evaluate the failure trend in plastic deformation based on the Freudenthal fracture criterion, and the effect of twinning volume fraction and grain size on the proposed factor was analyzed. The results indicate that higher twinning volume fraction improves strength and ductility, delays the failure of TWIP Steel. However, finer grain improves strength and ductility, but may deteriorate fracture resistance of TWIP Steel.
