The Experts below are selected from a list of 14121 Experts worldwide ranked by ideXlab platform
Xianghua Liu - One of the best experts on this subject based on the ideXlab platform.
-
adjusting the microstructure evolution mechanical properties and deformation behaviors of fe 5 95mn 1 55si 1 03al 0 055c medium mn steel by cold Rolling Reduction ratio
2020Co-Authors: Shu Yan, Taosha Liang, Xianghua LiuAbstract:Abstract For a representative medium Mn steel with the actual chemical composition of Fe-5.95 Mn-1.55Si-1.03Al-0.055 C (wt. %), the effect of cold-Rolling deformation on microstructural evolution and mechanical properties was investigated systematically. The thickness of coarse δ-ferrite grains decreases with the increase of cold-Rolling Reduction, and when the cold-Rolling Reduction ratio reaches up to a certain value, these δ-ferrite grains can be broken into small pieces due to the severe plastic deformation. Additionally, a critical cold-Rolling Reduction ratio for recrystallization exists. Below this critical Reduction value, the medium Mn steel after austenite reverted transformation (ART) annealing remains lath-shaped structure originating from the initial martensitic morphology, and when recrystallization occurs, however, submicron equiaxed grains dominate. The initial microstructure before ART annealing, which is usually determined by cold-Rolling Reduction, strongly influences not only the martensitic/ferritic matrix, but also reverted austenite grains. Non-recrystallization matrix promotes the formation of acicular reverted austenite, whereas recrystallization forces the austenite grains spherical and promotes the grain size of austenite homogenizing. Under the situation of non-recrystallization, the cold-Rolling Reduction prior to ART annealing only has a negligible effect on the final mechanical properties. However, the occurrence of recrystallization results in not only the yielding plateau, i.e., discontinuous yielding, but also the remarkable increase of yield strength.
-
by contRolling recrystallization degree a plain medium mn steel overcoming luders deformation and low yield to tensile ratio simultaneously
2019Co-Authors: Shu Yan, Taosha Liang, Jingqi Chen, Yang Zhao, Xianghua LiuAbstract:Abstract A technical process concept, i.e., contRolling recrystallization degree, was proposed and performed in order to manufacture the medium Mn steels overcoming discontinuous yielding and low yield-to-tensile ratio. Based on this, a plain medium Mn steel with 8.9 wt % Mn content was used in view of retarding recrystallization due to relatively high Mn content. The mechanical properties of the studied steel were evaluated by uniaxial tensile test at room temperature, and the detailed characterization of microstructural evolution was performed by scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The results show that the recrystallization process of the cold-rolled plates with 50% or 70% Rolling Reduction during ART annealing was effectively controlled, resulting in a desired mechanical behavior, i.e., high yield-to-tensile ratio, continuous yielding and outstanding combination of strength and ductility. This is because a certain proportion of deformed grains are retained due to incomplete recrystallization, which retains a higher density of mobile dislocation. This concept can be suggested to be quite suitable for the manufacturing of medium Mn steel using continuous annealing process, in which heating temperature and time can be controlled flexibly.
Leo Kestens - One of the best experts on this subject based on the ideXlab platform.
-
evolution of recrystallization textures in particle containing al alloys after various Rolling Reductions experimental study and modeling
2015Co-Authors: Jurij Sidor, Roumen Petrov, Koen Decroos, Leo KestensAbstract:Abstract The presence of large elastic constituent particles in aluminum alloys triggers strain heterogeneities in rolled materials. Finite element calculations demonstrate that the strain field in the vicinity of non-deformable particles strongly deviates from the macroscopic one, which induces a specific texture in the particle affected deformation zone during recrystallization. Results of the current study reveal that after various degrees of Rolling Reduction the corresponding recrystallization textures show significant qualitative and quantitative differences with respect to each other. The evolution of recrystallization textures is explained by a model which combines both orientation selection during nucleation and micro-growth selection. The current texture simulation provides very satisfactory results and suggests that the evolution of the {1 0 0}〈1 3 0〉 and {0 11 }〈2 3 3〉 components in recrystallized materials is related to the well-known particle stimulated nucleation mechanism.
-
influence of cold Rolling Reduction and cross Rolling on recrystallization texture formation in electro deposited pure iron with a sharp and homogeneous nd fiber
2014Co-Authors: Naoki Yoshinaga, D Vanderschueren, Leo Kestens, Kohsaku Ushioda, Natsuko SugiuraAbstract:The cold Rolling and annealing texture formation has been investigated in electro deposited pure iron which has an extremely sharp and isotropic //ND fiber. Regardless of cold Rolling Reduction, {111} intensified texture is formed after cold Rolling. Similar texture remains after recrystallization in 65% cold rolled material while {111} type texture forms in 80% and 90% cold rolled ones. The recrystallized grains at the stage of 5% recrystallization have {111} orientation in 65% cold rolled sheet, whereas {111} is observed in 80% cold rolled one. From this aspect, it is considered that the nucleation orientation plays an important role in the recrystallization texture formation. In the meanwhile, the growth of the recrystallized nuclei is also supposed to affect the recrystallization texture formation. The nuclei with {111} orientation in lightly cold rolled sheet are easier to consume the deformed matrix than they do in heavily cold rolled sheets because their frequency to encounter a deformed grain with nearly the same orientation is much smaller in lightly cold rolled specimen, which can result in a large mobility for growth. Cross cold Rolling makes cold Rolling texture rather homogeneous //ND fiber, which gives rise to an almost homogeneous //ND fiber after annealing.
-
texture evolution in si alloyed ultra low carbon steels after severe plastic deformation
2010Co-Authors: Patricia Gobernado, Roumen Petrov, D Ruiz, Elke Leunis, Leo KestensAbstract:Conventional thermomechanical processing of low-carbon steels leads to a characteristic texture dominated by a strong //ND fiber after recrystallization. The latter texture is beneficial for certain applications, such as deep drawing, while it is detrimental for others, including magnetic applications. With regard to magnetic applications, there is an ongoing effort to improve the final texture in ferromagnetic materials such as Fe-Si alloys used in transformers and electrical devices. Since the directions are the axes of easy magnetization, it is essential to produce a texture that maximizes the volume fraction of grains with a crystal direction in the flux direction. Bearing in mind that no phase transformation occurs during the processing of Fe-3% Si, plastic deformation and recrystallization are the prime contRolling instruments to generate an appropriate microstructure and texture. In this study, the potential of severe plastic Rolling deformation is considered. It is shown that, by strongly increasing the cold-Rolling Reduction, the volume fraction of the unfavourable {111} component is significantly decreased and the specific {113} component arises after annealing.
-
strain induced selective growth in an ultra low carbon steel after a small Rolling Reduction
2003Co-Authors: Kim Verbeken, Leo KestensAbstract:Abstract Recently, a consensus about the occurrence of selective growth during the final stages of recrystallization after severe cold Rolling has been reached. The possible role of variant selection during this selective growth mechanism is still questioned. For this reason, a Rolling and annealing experiment was carried out in which a ULC-steel after a first recrystallization treatment was submitted to three additional Rolling passes with an accumulated Reduction of 4.5%. In these three passes, the Rolling direction was inclined at 0, 90 and 45°, respectively, with respect to the hot Rolling direction in order to randomise the nucleation of recrystallization during a second annealing treatment. During this treatment, explosive grain growth occurred, which was associated with a texture evolution that promoted orientations that display the well-known 26.5° orientation relationship with respect to the initial texture. Almost all variants displaying this characteristic misorientation with respect to the parent component could be identified among the coarsened grains.
Shu Yan - One of the best experts on this subject based on the ideXlab platform.
-
adjusting the microstructure evolution mechanical properties and deformation behaviors of fe 5 95mn 1 55si 1 03al 0 055c medium mn steel by cold Rolling Reduction ratio
2020Co-Authors: Shu Yan, Taosha Liang, Xianghua LiuAbstract:Abstract For a representative medium Mn steel with the actual chemical composition of Fe-5.95 Mn-1.55Si-1.03Al-0.055 C (wt. %), the effect of cold-Rolling deformation on microstructural evolution and mechanical properties was investigated systematically. The thickness of coarse δ-ferrite grains decreases with the increase of cold-Rolling Reduction, and when the cold-Rolling Reduction ratio reaches up to a certain value, these δ-ferrite grains can be broken into small pieces due to the severe plastic deformation. Additionally, a critical cold-Rolling Reduction ratio for recrystallization exists. Below this critical Reduction value, the medium Mn steel after austenite reverted transformation (ART) annealing remains lath-shaped structure originating from the initial martensitic morphology, and when recrystallization occurs, however, submicron equiaxed grains dominate. The initial microstructure before ART annealing, which is usually determined by cold-Rolling Reduction, strongly influences not only the martensitic/ferritic matrix, but also reverted austenite grains. Non-recrystallization matrix promotes the formation of acicular reverted austenite, whereas recrystallization forces the austenite grains spherical and promotes the grain size of austenite homogenizing. Under the situation of non-recrystallization, the cold-Rolling Reduction prior to ART annealing only has a negligible effect on the final mechanical properties. However, the occurrence of recrystallization results in not only the yielding plateau, i.e., discontinuous yielding, but also the remarkable increase of yield strength.
-
by contRolling recrystallization degree a plain medium mn steel overcoming luders deformation and low yield to tensile ratio simultaneously
2019Co-Authors: Shu Yan, Taosha Liang, Jingqi Chen, Yang Zhao, Xianghua LiuAbstract:Abstract A technical process concept, i.e., contRolling recrystallization degree, was proposed and performed in order to manufacture the medium Mn steels overcoming discontinuous yielding and low yield-to-tensile ratio. Based on this, a plain medium Mn steel with 8.9 wt % Mn content was used in view of retarding recrystallization due to relatively high Mn content. The mechanical properties of the studied steel were evaluated by uniaxial tensile test at room temperature, and the detailed characterization of microstructural evolution was performed by scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The results show that the recrystallization process of the cold-rolled plates with 50% or 70% Rolling Reduction during ART annealing was effectively controlled, resulting in a desired mechanical behavior, i.e., high yield-to-tensile ratio, continuous yielding and outstanding combination of strength and ductility. This is because a certain proportion of deformed grains are retained due to incomplete recrystallization, which retains a higher density of mobile dislocation. This concept can be suggested to be quite suitable for the manufacturing of medium Mn steel using continuous annealing process, in which heating temperature and time can be controlled flexibly.
G J Wang - One of the best experts on this subject based on the ideXlab platform.
-
effect of final Rolling Reduction on the microstructure and mechanical properties of mg gd y zn zr alloy sheets
2013Co-Authors: Chao Xu, M Y Zheng, Kun Wu, E D Wang, S W Xu, Shigeharu Kamado, G J Wang, X Y Lv, M J LiAbstract:Abstract The Mg–8.2Gd–3.8Y–1.0Zn–0.4Zr (wt.%) alloy was hot rolled with different final Rolling Reductions at 400 °C. The microstructure evolution and texture of the sheets were analyzed, and their effect on the mechanical properties was discussed. All of the rolled sheets consist of fine dynamically recrystallized grains with almost random orientation, large deformed grains with strong basal texture. In addition, bent lamellar-shaped long period stacking ordered (LPSO) phases due to kink deformation were observed in the deformed grains. The volume fraction of the dynamic recrystallization increased with increasing final Rolling Reduction and the basal texture weakened gradually. The strength of the alloy sheets changed a little with increasing final Rolling Reduction, while the yield anisotropy and the ductility were significantly improved. The sheet final-rolled with thickness Reduction of 60% exhibits tensile yield strength of 306 MPa, ultimate tensile strength of 393 MPa and elongation to failure of 14.6% at ambient temperature, and tensile yield strength of 264 MPa, ultimate tensile strength of 345 MPa and elongation to failure of 19.4% at 250 °C.
-
microstructures and mechanical properties of high strength mg gd y zn zr alloy sheets processed by severe hot Rolling
2012Co-Authors: M Y Zheng, E D Wang, Shigeharu Kamado, G J WangAbstract:Abstract Mg–8.2Gd–3.8Y–1.0Zn–0.4Zr alloy sheets containing long period stacking ordered (LPSO) phase were prepared by hot Rolling at 400 °C with total Reduction of 96%. Microstructure evolution of the sheets during hot Rolling was investigated, and its influence on mechanical properties was discussed. Twinning occurred during the early stage of hot Rolling, and disappeared after total Reduction higher than 89%. Average grain size was gradually refined, microstructure became much more homogeneous and volume fraction of LPSO phase decreased with increasing Rolling Reduction. Furthermore, the type of LPSO phases far from and near the block shaped phases were identified to be different. Basal texture was obtained during Rolling process, but the intensity declined with the further Rolling, which is mainly due to the dynamic recrystallization and the addition of RE elements. The as-rolled sheet with 96% Reduction shows excellent mechanical properties: yield strength of 318 MPa, ultimate tensile strength of 403 MPa and elongation to failure of 13.7% at ambient temperature along the Rolling direction.
Qiwen Wang - One of the best experts on this subject based on the ideXlab platform.
-
effect of Rolling Reduction on antiphase domains grain boundary character distribution and plastic deformation of fe 6 5 wt si alloy
2019Co-Authors: Guojun Cai, Ban Cai, Qiwen WangAbstract:Abstract The variation in plastic deformation of Fe-6.5 wt%Si alloy depends on antiphase domains and grain boundary character distribution. With the increase of Rolling Reductions from 50% to 85%, the increment of dislocation density causes decline of the sizes of antiphase domains, meanwhile the sharp and homogeneous distribution of γ-fiber texture is prone to obtaining a large fraction of CSL boundaries, thus the fracture deflection of 65% warm-rolled sheet is increased to 8.6 mm by 38.7% in comparison to that of 50% warm-rolled sheet (6.2 mm), and that of 85% warm-rolled sheet has nearly three times increment (18.2 mm).
