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Rintaro Ueji - One of the best experts on this subject based on the ideXlab platform.

  • effect of initial grain size on inhomogeneous plastic deformation and twinning behavior in high Manganese Austenitic Steel with a polycrystalline microstructure
    Microelectronics Systems Education, 2015
    Co-Authors: Rintaro Ueji, Noriyuki Tsuchida, Kenji Harada, K Takaki, Hidetoshi Fujii
    Abstract:

    The grain size effect on the deformation twinning in a high Manganese Austenitic Steel which is so-called TWIP (twining induced plastic deformation) Steel was studied in order to understand how to control deformation twinning. The 31wt%Mn-3%Al-3% Si Steel was cold rolled and annealed at various temperatures to obtain fully recrystallized structures with different mean grain sizes. These annealed sheets were examined by room temperature tensile tests at a strain rate of 10-4/s. The coarse grained sample (grain size: 49.6μm) showed many deformation twins and the deformation twinning was preferentially found in the grains in which the tensile axis is parallel near to [111]. On the other hand, the sample with finer grains (1.8 μm) had few grains with twinning even after the tensile deformation. The electron back scattering diffraction (EB SD) measurements clarified the relationship between the anisotropy of deformation twinning and that of inhomogeneous plastic deformation. Based on the EBSD analysis, the mechanism of the suppression of deformation twinning by grain refinement was discussed with the concept of the slip pattern competition between the slip system governed by a grain boundary and that activated by the macroscopic load.

  • crystallographic orientation dependence of e martensite transformation during tensile deformation of polycrystalline 30 mn Austenitic Steel
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2013
    Co-Authors: Rintaro Ueji, Noriyuki Tsuchida, Yasuhiro Tanaka, Yoshinori Takagi, Kazunari Shinagawa, Takashi Mizuguchi
    Abstract:

    Abstract The dependence of the e martensite transformation on the crystallographic orientation during a tensile test of metastable high-Manganese Austenitic Steel, Fe–30 mass% Mn, with a polycrystalline microstructure was studied. The e martensite plates were formed after the Steel yielded by slipping, and the volume fraction of the e martensite increased with increasing strain. No significant orientation dependence of the martensite formation was observed in the early stage of the tensile deformation, but when the sample was further strained up to about 30%, the tensile directions of the grains with martensite were preferentially found to be nearly parallel to the 〈111〉 direction of the austenite matrix. This orientation dependence corresponded with the orientation preferable for the development of local misorientations as detected by EBSD.

  • tensile deformation behavior of high Manganese Austenitic Steel the role of grain size
    Materials & Design, 2010
    Co-Authors: Ghasem Dini, Rintaro Ueji, A Najafizadeh, S M Monirvaghefi
    Abstract:

    Abstract The tensile deformation behavior and microstructural evolutions of twinning induced plasticity (TWIP) Steel with the chemical composition of Fe–31Mn–3Al–3Si and average grain sizes in the range of 2.1–72.6 μm have been analyzed. For each grain size, the Hollomon analysis and also the Crussard–Jaoul (C–J) analysis as an alternative method to describe the work hardening behavior were investigated. The results indicated that the optimum mechanical properties as a function of work hardening capacity can be obtained by changing the grain size. The microstructural observations showed that the pile-ups of planar dislocations are necessary for triggering the mechanical twinning and grain refinement suppresses the mechanical twinning in TWIP Steel. Furthermore, the mechanical twinning increases with increasing applied strain. As a result, a high instantaneous work hardening due to the mechanical twin boundaries enhances the uniform elongation. The contribution from the strain of twinning and hardening due to an increase in the hardness of the twinned regions (i.e., the Basinski mechanism) may be also useful in achieving the high strength–ductility in TWIP Steels.

  • tensile properties and twinning behavior of high Manganese Austenitic Steel with fine grained structure
    Scripta Materialia, 2008
    Co-Authors: Rintaro Ueji, Nobuhiro Tsuji, Noriyuki Tsuchida, Daisuke Terada, Yasuhiro Tanaka, A Takemura, Kazutoshi Kunishige
    Abstract:

    High Manganese Austenitic Steels with various mean grain sizes (1.8, 7.2, 49.6 μm) were tensile tested and their twinning behaviors were studied. The fine-grained Steel (d = 1.8 μm) showed high strength with adequate ductility. Deformation twinning was strongly inhibited by grain refinement. These observations suggest that the reason for the large ductility lies on not only the twinning but also in the suppressed dynamic recovery due to low stacking fault energy.

Ashok Kumar Srivastava - One of the best experts on this subject based on the ideXlab platform.

  • microstructure and abrasive wear study of ti w c reinforced high Manganese Austenitic Steel matrix composite
    Materials Letters, 2008
    Co-Authors: Ashok Kumar Srivastava
    Abstract:

    Abstract A high-Manganese Austenitic Steel matrix composite (Fe–1.42%C–16.02%Mn–0.447%Si–0.288%Al–0.34%Cr–0.028%S–0.25%P–3.02%Ti–3.0%W, all in wt.%) reinforced with in-situ (Ti,W)C was synthesized by conventional melting and casting route. It has been found that the concentration of Ti decreases whereas the concentration of tungsten increases from core to the periphery of the (Ti,W)C particulates. The abrasive wear resistance of as-cast (Ti,W)C-reinforced composite is better than that of the as-cast high-Manganese Austenitic Steel matrix material.

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

  • the role of twinning on microstructure and mechanical response of severely deformed single crystals of high Manganese Austenitic Steel
    Materials Characterization, 2011
    Co-Authors: E G Astafurova, Eugene Melnikov, M S Tukeeva, G G Zakharova, H J Maier
    Abstract:

    Abstract The role of mechanical twinning on the fragmentation and the contribution to strengthening was studied using single crystals of Hadfield Steel after high-pressure torsion and rolling at room temperature. Multiple twinning was found to be the basic deformation mechanism responsible for the fast generation of an ultrafine-grained microstructure with twin boundaries in Hadfield Steel single crystals after severe cold plastic deformation. As a result, the hardness of the Hadfield Steel increased noticeably.

  • fatigue crack growth microstructure relationships in a high Manganese Austenitic twip Steel
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2010
    Co-Authors: Thomas Niendorf, F Rubitschek, H J Maier, J Niendorf, Hans Albert Richard, Andreas Frehn
    Abstract:

    The crack growth behavior of a high-Manganese Austenitic Steel, which exhibits the twinning-induced plasticity (TWIP) effect, was investigated under positive stress ratios. An experimental study making use of miniature compact tension (CT) specimens and thorough microstructural analyses including transmission electron microscopy and fracture analyses demonstrated that the microstructural evolution in the plastic zone of the fatigued TWIP CT specimens is substantially different as compared to the monotonic plastic deformation case. Specifically, the twin density in the plastic zone of the CT specimens is very low, leading to the conclusion that the deformation mechanisms depend drastically on the loading conditions. The absence of twinning under cyclic loading in the plastic zone of the CT specimens indicates that even large accumulated plastic strains are not sufficient to cause substantial twinning in the TWIP Steel. This lack of hardening preserves the ductile character of the TWIP Steel in the plastic zone ahead of the crack tip and provides for a crack growth rate in the Paris regime lower than reported for other high strength Steels.

  • the role of monotonic pre deformation on the fatigue performance of a high Manganese Austenitic twip Steel
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2009
    Co-Authors: Thomas Niendorf, Andreas Frehn, C Lotze, D Canadinc, H J Maier
    Abstract:

    The fatigue performance of a high-Manganese Austenitic Steel featuring the twinning-induced plasticity (TWIP) effect was investigated in both thermomechanically treated rolled and pre-deformed conditions. A thorough set of mechanical experiments and microstructural analyses demonstrated that microstructural evolutions during high-strain monotonic and low-strain cyclic deformations differ significantly. Specifically, a high twin density is obtained as a result of monotonic deformation, and a low twin density, yet a noticeable increase in twin thickness, is observed in the fatigued samples. Furthermore, the fatigue performance of the pre-deformed TWIP Steel samples is superior to that of the as-received Steel, which is attributed to the enhanced interaction of glide dislocations with twins of increased density owing to the monotonic pre-deformation.

Andreas Frehn - One of the best experts on this subject based on the ideXlab platform.

  • fatigue crack growth microstructure relationships in a high Manganese Austenitic twip Steel
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2010
    Co-Authors: Thomas Niendorf, F Rubitschek, H J Maier, J Niendorf, Hans Albert Richard, Andreas Frehn
    Abstract:

    The crack growth behavior of a high-Manganese Austenitic Steel, which exhibits the twinning-induced plasticity (TWIP) effect, was investigated under positive stress ratios. An experimental study making use of miniature compact tension (CT) specimens and thorough microstructural analyses including transmission electron microscopy and fracture analyses demonstrated that the microstructural evolution in the plastic zone of the fatigued TWIP CT specimens is substantially different as compared to the monotonic plastic deformation case. Specifically, the twin density in the plastic zone of the CT specimens is very low, leading to the conclusion that the deformation mechanisms depend drastically on the loading conditions. The absence of twinning under cyclic loading in the plastic zone of the CT specimens indicates that even large accumulated plastic strains are not sufficient to cause substantial twinning in the TWIP Steel. This lack of hardening preserves the ductile character of the TWIP Steel in the plastic zone ahead of the crack tip and provides for a crack growth rate in the Paris regime lower than reported for other high strength Steels.

  • the role of monotonic pre deformation on the fatigue performance of a high Manganese Austenitic twip Steel
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2009
    Co-Authors: Thomas Niendorf, Andreas Frehn, C Lotze, D Canadinc, H J Maier
    Abstract:

    The fatigue performance of a high-Manganese Austenitic Steel featuring the twinning-induced plasticity (TWIP) effect was investigated in both thermomechanically treated rolled and pre-deformed conditions. A thorough set of mechanical experiments and microstructural analyses demonstrated that microstructural evolutions during high-strain monotonic and low-strain cyclic deformations differ significantly. Specifically, a high twin density is obtained as a result of monotonic deformation, and a low twin density, yet a noticeable increase in twin thickness, is observed in the fatigued samples. Furthermore, the fatigue performance of the pre-deformed TWIP Steel samples is superior to that of the as-received Steel, which is attributed to the enhanced interaction of glide dislocations with twins of increased density owing to the monotonic pre-deformation.

Thomas Niendorf - One of the best experts on this subject based on the ideXlab platform.

  • fatigue crack growth microstructure relationships in a high Manganese Austenitic twip Steel
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2010
    Co-Authors: Thomas Niendorf, F Rubitschek, H J Maier, J Niendorf, Hans Albert Richard, Andreas Frehn
    Abstract:

    The crack growth behavior of a high-Manganese Austenitic Steel, which exhibits the twinning-induced plasticity (TWIP) effect, was investigated under positive stress ratios. An experimental study making use of miniature compact tension (CT) specimens and thorough microstructural analyses including transmission electron microscopy and fracture analyses demonstrated that the microstructural evolution in the plastic zone of the fatigued TWIP CT specimens is substantially different as compared to the monotonic plastic deformation case. Specifically, the twin density in the plastic zone of the CT specimens is very low, leading to the conclusion that the deformation mechanisms depend drastically on the loading conditions. The absence of twinning under cyclic loading in the plastic zone of the CT specimens indicates that even large accumulated plastic strains are not sufficient to cause substantial twinning in the TWIP Steel. This lack of hardening preserves the ductile character of the TWIP Steel in the plastic zone ahead of the crack tip and provides for a crack growth rate in the Paris regime lower than reported for other high strength Steels.

  • the role of monotonic pre deformation on the fatigue performance of a high Manganese Austenitic twip Steel
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2009
    Co-Authors: Thomas Niendorf, Andreas Frehn, C Lotze, D Canadinc, H J Maier
    Abstract:

    The fatigue performance of a high-Manganese Austenitic Steel featuring the twinning-induced plasticity (TWIP) effect was investigated in both thermomechanically treated rolled and pre-deformed conditions. A thorough set of mechanical experiments and microstructural analyses demonstrated that microstructural evolutions during high-strain monotonic and low-strain cyclic deformations differ significantly. Specifically, a high twin density is obtained as a result of monotonic deformation, and a low twin density, yet a noticeable increase in twin thickness, is observed in the fatigued samples. Furthermore, the fatigue performance of the pre-deformed TWIP Steel samples is superior to that of the as-received Steel, which is attributed to the enhanced interaction of glide dislocations with twins of increased density owing to the monotonic pre-deformation.