Papers by Keyword: Recrystallization Texture

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Authors: Hirofumi Inoue
Abstract: A new rolling process, which combined asymmetric rolling with symmetric rolling, was adopted in age-hardenable 6xxx series Al-Mg-Si alloy promising as automotive body panels in order to develop favorable textures for the deep drawability after solution treatment. Symmetric cold rolling at high reduction and subsequent asymmetric warm rolling at low reduction for AA6022 sheets led to the formation of “TD-rotated β-fiber texture” including moderate {111}<uvw>-oriented components, resulting in noticeable evolution of {111}<110> recrystallization texture during the solution treatment at a high temperature. The results of texture analysis and microstructural observation suggested that the low stored energy after asymmetric warm rolling, the high fraction of high angle boundaries with neighboring deformed matrices and the approximate 40° <111> orientation relationship with deformed matrices would strongly affect the evolution of {111}<110> recrystallization texture.
Authors: Zheng Rong Zhang, Kazuyoshi Sekine
Abstract: In order to obtain a sharply cube textured silver sheet as the substrate for high temperature superconductor (HTS) film with high Jc (critical current density), warm rolling combined with two step annealing treatment has been performed to clarify the perspective of texture formation in pure silver. Two kinds of starting material, which are silver ingots of commercial purity obtained by casting in air and vacuum, were used to examine the effect of oxygen on texture development. The main feature of warm rolling texture obtained in this study was a strong Brass {011}<211> component with minor S {123}<412> component, and in some cases, cube {001}<100> component or Copper {112}<111> component appeared also depending on the warm rolling procedures. Upon crystallization, {001}<100>, {124}<4,12,7> and {13,6,15}<365> orientations were formed as the dominant components in silver sheets and the relative amount of their orientation components depended on the concrete annealing conditions applied and on the oxygen content. A very sharp single-crystal like cube texture has been successfully realized in the specimen, which was cast in vacuum, warm rolled by 95 percent and subsequently annealed as 1500C×10 min-5000C×30 min in nitrogen. Finally, we discussed the technological basis on sharp cube texture formation in f.c.c. pure metals with low stacking fault energy.
Authors: Jerzy A. Szpunar
Authors: Dorte Juul Jensen, R.K. Bolingbroke, Hong Shi, Ravi Shahani, Trond Furu
Authors: Toshiharu Morimoto, Y. Fuyuki, A. Yanagida, Jun Yanagimoto
Abstract: T.M.C.P.(Thermo Mechanical Control Processing) has been widely used to improveplastic formability in steel strips. We have produced interstitial free steel(IF steel) strips and ferriticstainless-steel strips through T.M.C.P. rolling method. Optimizing conditions of hot rolling, hotrolled annealing, cold rolling and cold rolled annealing, we developed texture prediction model. Wecan predict rolling texture accurately using the conventional Taylor model. Moreover, we preciselypredict recrystallization texture classifying the total number of microscopic􀀁 slips which arecalculated using the Taylor model. We consider that these calculated results provednucleation-oriented model and two types of recrystallization and grain growth mechanisms exit inour studies. One mechanism is that grains which had the small total number of microscopic slips arepreferred orientation for the hot rolled and annealed ferritic stainless-steel strip. The othermechanism is that grains which had the high total number of microscopic slips are preferredorientation for the cold rolled and annealed IF steel strip.
Authors: Dong Nyung Lee, Heung Nam Han, Hyun Sik Choi
Abstract: The texture of rolled sheets is known to vary with depth from the surface to the center due to inhomogeneous deformation, which can be caused by a characteristic deformation zone geometry and friction between materials and rolls during rolling. In order to study the deformation and recrystallization (Rex) textures of the surface layers of Al and Cu sheets cold rolled without lubrication, 5 Al sheets were stacked and rolled by 88% and 4 Cu sheets were stacked and rolled by 93% in 4 passes at room temperature. The surface layers separated from the rolled sheets were annealed for 1 h at 500 °C for Al and at 550 °C for Cu. The deformation textures of the surface layers were characterized by different shear textures, which gave rise to very different Rex textures.
Authors: Iskandar Muda, Azwar Manaf, Jeffrey W. Fergus
Authors: M. Sánchez-Araiza, Stéphane Godet, Pascal J. Jacques, John J. Jonas
Abstract: In warm rolled steels, the intensity of the <111>//ND annealing texture, which favours formability, has been related to the formation of shear bands during rolling. Coarse hot band grain sizes (HBGS’s) facilitate flow localization, the mechanism associated with the formation of shear bands.In this work, the effect of grain size after hot rolling was studied in a low carbon steel containing small additions of Cr and Mn. The formation of shear bands and their subsequent influence on the normal anisotropy rm and planar anisotropy Dr in the annealed steels were of particular interest. Two HBGS’s (18 and 30mm) were employed and the specimens were warm rolled to reductions of 65 and 80% at various temperatures between 640 and 700°C. The results show that the frequency of shear banding is slightly lower for the smaller grain size. The normal anisotropy was not affected by the HBGS; by contrast, much lower Dr values were associated with the finer grained steel.
Authors: Daniella Gomes Rodrigues, Cláudio Moreira Alcântara, Dagoberto Brandão Santos, Tarcísio Reis de Oliveira, Berenice Mendonça Gonzalez
Abstract: The ferritic stainless steels are materials used in several segments due to the excellent combination of mechanical properties and corrosion resistance. The mechanical properties of these alloys are strongly dependent on the microstructural characteristics and crystallography texture. The aim of this experimental study is to investigate the roles of the grain size of the hot rolled sample on the development of the microstructure, texture and formability of ferritic stainless steel. The main elements of chemical composition of the steel under investigation were 16.0 %Cr, 0.021 %C, 0.024 %N and 0.35 %Nb. Coarse and fine grains samples were cold rolled up to 90% thickness reduction and annealed at 880°C with soaking time of the 24 s. The texture measurements were performed by Electron Backscattered Diffraction (EBSD) in the longitudinal section. The formability was evaluated by the R-value and planar anisotropy (Δr) in tensile tests. The final microstructure after annealed was more homogenous for smaller initial grain size sample. This condition was favorable to develop γ-fiber, with sharpness intensity in 111121 components. The highest R-value and smallest planar anisotropy was obtained for a {111}/{001} ratio around 5.37. On the other hand, coarser initial grain size sample had showed a heterogeneous microstructure and texture, performing badly in mechanical tests (anisotropy).
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