Development Of Rolling Textures Research Articles

Effect of Rolling Reduction on the Development of Rolling and Recrystallization Textures in Al-Mg Alloys

Effect of Rolling Reduction on the Development of Rolling and Recrystallization Textures in Al-Mg Alloys

Hot rolling texture development in CMnCrSi dual-phase steels

The amount of strain below the temperature of nonrecrystallization, Tnr, has an important influence on the phase fractions and the final crystallographic texture of a hot-rolled dual-phase ferrite+martensite CMnCrSi steel. The final texture is influenced by three main microstructural processes: the recrystallization of the austenite, the austenite deformation, and the austenite-to-ferrite transformation. The amount of strain below Tnr plays a major role in the relative amounts of deformed and recrystallized austenite after rolling. Recrystallized and deformed austenite have clearly different texture components and, due to the specific lattice correspondence relations between the parent austenite phase and its transformation products, the resulting ferrite textures are different as well. In addition, austenite deformation textures result from either dislocation glide or the combination of dislocation glide and mechanical twinning, depending on the stacking fault energy (SFE). The texture components in hot-rolled dual-phase steels were studied by means of X-ray diffraction (XRD) measurements and orientation imaging microscopy (OIM). A clear crystallographic orientation difference was observed between the ferrite phase, transformed at temperatures near Ar3, and the ferritic bainite and martensite phases, formed at lower temperatures. The results suggest that the primary ferrite, nucleated at temperatures close to Ar3, transformed from the deformed austenite. The low-temperature constituents, bainite and martensite, form in the recrystallized austenite.

Evolution of cold rolling texture in the binary alloys: Ti–0.4Mn and Ti–1.8Mn

This work describes the evolution of texture during cold rolling of the titanium alloys Ti–0.4Mn and Ti–1.8Mn. The development of the cold rolling textures has been examined from 5 to 75% reduction. In order to compare the effect of different deformation modes on texture formation, two specimens of each alloy were subjected to 75% reduction by multi-step cross and reverse rolling. The rolling textures obtained in this study are compared with those of pure titanium and other titanium alloys in the literature.

Preparation and evaluation of cube texture Ni substrate for YBCO-coated superconductor

The cube-textured Ni tapes were prepared by deformation rolling at room temperature and followed by recrystallization annealing at 950–1000°C for 5–10 h in a high vacuum under 10 −4 Pa. The formation and evolution of rolling and recrystallization textures have been investigated by X-ray pole figures and orientation distribution function (ODF). The results show that the C {112}〈1117〉 and S {123}〈634〉 orientation densities along β-fiber in rolling textures of Ni substrate increase with increasing reductions; and the cube texture volume fraction index increases, ϕ scan FWHM decreases with increasing heat-treatment temperatures for samples deformed with 95% reduction. In the recrystallization textures, the cube texture component in ODF ϕ=0 section deviates from regular positions (0° 0° 0°) in the range of 12–13° at lower heat-treatment temperature. By increasing the heat-treatment temperature up to 1000°C, the deviation from regular position decreases, and sharp cube texture is formed.

The Influence of Tension on the Development of Rolling Textures

The texture inhomogeneity during rolling is one of the greatest problems. Especially, shear textures develops more easily during ferritic rolling of steel sheets at high temperatures owing to friction between rolls and the material. In this study, the influence of front and back tensions on the texture development during ferritic rolling has been studied. The rolling textures were simulated using the full constraints Taylor-Bishop-Hill model with the strain history obtained from finite element analysis. The calculated textures showed that the back tension rolling could reduce the shear component more effectively than front tension or rolling without tension. However, the experimental results showed that the tension effect was very small compared to the prediction. The results were discussed based on the effects of friction, initial sheet texture, back tension, and flow stress.

Evolution of hot rolling textures in a two-phase ( α2+ β) Ti 3Al base alloy

Texture development during thermomechanical processing of two-phase ( α 2+ β) Ti–24Al–11Nb alloy was studied as a function of variables like initial microstructure, rolling temperature, cooling conditions, etc. The evolution of texture in different conditions has been critically analysed. It has been found that unrestricted rolling of primary α 2 at lower temperature leads to a good basal {0001}〈 uvtw〉 texture, while at higher temperatures, the α 2→ β→ α 2 phase transformation leads to weakening of the basal texture. Texture of secondary α 2 derived from rolled β is generally non-basal. However, the texture of secondary α 2 derived from recrystallized β has a basal character.

Deformation banding and nucleation of recrystallisation in if steel

In an investigation of the properties of the model proposed by Liu et al. for the development of BCC rolling textures incorporating Deformation Banding (DB) certain crystal rotation paths were encountered which were recognized as being pertinent to the ongoing debate as to the origins of the {l_brace}111{r_brace} recrystallization texture in IF steels. For the case of steel, grain subdivision into bands was observed in longitudinal and rolling plane sections by optical and SEM imaging. It was also progressive, i.e., the number of grains subdividing into these bands increased with strain. At low strains the grains fragmented into regions in which different slip systems were operating, and these grain fragments eventually became well developed bands at higher strains. The early and later stages are both called deformation banding (DB) because they are part of the process which develops pancake elements parallel to the rolling plane and well known by this name to many metallographers. Banding in the longitudinal section follows the principle of the relaxed constraints (RC) model, but without orientation splitting, in other words, banding in these sections is ignored and the DB model is one dimensional. To ensure that DB occurs in the model, a latent hardening parameter,more » L{sub n} is introduced, which is multiplied by the CRSS of slip planes which do not belong to the most heavily stressed slip plane. Since L{sub n} is set at 1.2, this has the effect of limiting the number of slip systems to an average of 2 per band. The simulation can be done with 110, 112, and 123 slip either in combination or singly, and DB occurs from the first increment in strain, with relaxation of the longitudinal elements following the RC procedure.« less

Characteristic Features of Rolling Texture Development in FCC Alloys Having Very Low Stacking Fault Energies

The aim of this paper is to clarify the difference in textural behavior during rolling between low and very low stacking fault energy fcc materials. The rolling texture developments of pure silver and Ag-Zn solid solution alloys containing 8 mass% and 18 mass%Zn were investigated in detail by means of the X-ray texture analysis including the reliable calculations of the orientation distribution function for a wide range of rolling reduction. At higher reductions in thickness (> 95%), the terminal textures in all specimens of Ag and Ag-Zn alloys were almost similar, and they exhibited the typical brass type rolling texture in which the dominant {110} was developed with the minor component of { 110} . However, it was found at medium degrees of reduction (approximately 50%-75%) that the Ag-Zn alloys having very low stacking fault energies behaved in remarkably different fashion compared to the silver alloy with a moderately low value of stacking fault energy. In such a medium region of rolling reduction, the formation of {111} type component which should be considered as a distinct texture component of very low stacking fault energy alloys, such as Ag-Zn alloys, were enhanced with increasing Zn content. This characteristic feature appearing in the rolling texture of very low stacking fault energy alloys is discussed in terms of the non-Wassermann effect of deformation twinning which has been suggested by one of the authors already.

Rolling texture in the intermetallic compound Ni76Al24(B)

The development of cold rolling texture in the intermetallic compound Ni3Al(B) has been investigated as a function of rolling reduction, using the conventional pole figure as well as the orientation distribution functions (ODF) method. The textures at low degrees of deformation have been found to be similar to the rolling texture of pure Ni cold rolled to similar levels. With increasing degree of deformation, the texture in Ni3Al(B) changes to alloy type at reductions greater than 45%. This texture is characterized by the presence of a remarkably strong rotated Goss component over and above the Brass (Bs) component. Transmission electron microscopy of thin foils of the material cold rolled by 65% and more shows evidence of twinning. X-ray diffraction analysis indicates a structural change in the material from L12 to DO22 with the progress of cold work. An attempt has been made to explain the texture development in terms of this structural transformation.

The Effect of Shear Bands on the Evolution of Rolling and Recrystallization Texture in Cold-Rolled Direct Chill Cast Strips of Brass

The texture of cold rolled and annealed cast strips of 70/30 brass was investigated. A delayed development of the main {110} component of brass type rolling texture was attributed to the intense deformation twinning which is associated with appearance of the strong {211} texture component at 50% reduction. The predominace of the {011} texture component in the range of 70%-90% reductions was related to the extensive shear banding. As for the rolling textures, the delay in development of the {236} component of brass type recrystallization texture was found.

アルミニウム合金の異方性と成形性 １０５０アルミニウム薄板の拡幅圧延

A rolling method to increase the width of materials would have advantages in multi-width strip production, yield efficiency, productivity and texture control. The authors proposed a new method for spread rolling of thin and wide strip. The method employs 3-pass caliber rolling, where several portions of the width are reduced. In this study, the method was applied to commercial 1050 Aluminum strips. Necking or fracture occurred at thin portions near edges. In order to prevent the occurrence of defects, the method is improved to the 5-pass rolling method. It is found that the 5-pass rolling is effective in lateral spread as well as in preventing in defects formation. Thin aluminum strips with an aspect ratio (width/thickness) of 100 are successfully widened up to 3% by 30%–reduction rolling. As for the mechanical properties of rolled strips, the spread strips are slightly work-hardened than those of the flat strip. Development of rolling texture is not so remarkable in the spread strips as that in the flat-rolled strips. It is concluded that the proposed spread rolling method can control the texture as well as the width of rolled strips.

Comportement élastoplastique anisotrope pour l'analyse numérique des coques minces en grandes transformations

ABSTRACT Due to rolling and cristallographie texture development, thin sheets metal for stamping exhibit an initial orthotropic plastic behaviour that have to be incorporated in numerical modelling of sheet forming processes. A mechanical modelling of the behaviour is presented. It is based on a formulation in a rotating frame updatted using the proper rotation tensor. The stress calculation algoritlim associated is based on the prediction-correction method in the rotating frame and explicitly takes into account shell kinematics with mixed transverse shear interpolation. Numerical results on deep drawing problems show the accuracy and the efficiency of the proposed approach.

Hot rolling textures of f.c.c. metals—Part II. Numerical simulations

The development of hot rolling textures in f.c.c. metals has been simulated numerically using a viscoplastic crystal plasticity model assuming different combinations of octahedral and non-octahedral slip systems for several grain-matrix interaction schemes. A combination of quasi-pencil glide and the Lebensohn and Tomé self-consistent model [ Acta Metall. Mater., 1993, 41, 2611] gives a satisfactory simulation of typical hot rolling f.c.c. texture components, i.e. well balanced β-fibre components and a small amount of “Cube”.

Modeling of rolling texture development in a ferritic chromium steel

The development of crystallographic texture during rolling of a ferritic chromium steel containing 11 pct Cr was examined experimentally as well as by polycrystal modeling at large strains (up to 90 pct thickness reduction). The initial shape of the grains was very much elongated in the direction of rolling. A strong rolling direction (RD) fiber ( parallel to the rolling direction) has been observed at large strains in the experiment. The Taylor viscoplastic model, the relaxed-constraints pancake model, and the self-consistent viscoplastic approach were employed to simulate the texture development. Strain hardening was accounted for by microscopic hardening laws, for which the parameters were obtained from uniaxial tensile tests. It has been found that among the three models considered, the self-consistent viscoplastic model (the version tuned to finite-element results) yielded the best agreement with the experimentally observed texture evolution. Strong effects of grain shape and hardening have been found. The pancake model was also able to reproduce the main characteristics of the texture because of the flattened initial grain shape.

Numerical implementation of orthotropic plasticity for sheet-metal forming analysis

Due to rolling and crystallographic texture development, thin sheet-metal for stamping exhibits an initial orthotropic plastic behaviour. The objective of the present work is to define a stress-computation algorithm taking into account this anisotropic plastic behaviour and the update of the orthotropic frame directions within a finite-element simulation of sheet-metal forming. Following Mandel's approach, a macroscopic behaviour model is considered which is based on the use of a rotational objective derivative defined from the initial micro-structure rotation governing the orthotropic direction update. The expression of the constitutive law in a frame rotated by this rotation permits a numerical scheme including an elastic prediction and a plastic correction for the stress calculation. The elastic prediction ensures the incremental objectivity and a second-order level of accuracy. The correction stage is based on an implicit Euler-backward scheme and leads to the solution of a non-linear equation using a local Newton method. In the proposed simulation approach, C 0 shell finite elements are used to model the blank. The proposed stress-calculation algorithm takes into account the mixed interpolation used in the element formulation in order to avoid shear locking. A set of numerical results is presented in cases of the simulation of deep-drawing processes. The accuracy of the solutions, and especially the good agreement with experimental results, shows the efficiency of the proposed approach.

ファジィ理論による多結晶塑性論の定式化と体心立方金属の圧延集合組織形成のシミュレーション

ファジィ理論による多結晶塑性論の定式化と体心立方金属の圧延集合組織形成のシミュレーション

Cold rolling texture development of α/γ duplex stainless steels

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On the influence of the chromium content on the evolution of rolling textures in ferritic stainless steels

The crystallographic hot and cold rolling textures of various ferritic stainless steels with 10.5–16.5 wt% Cr content were investigated by use of quantitative texture analysis. The hot-rolled specimens revealed a texture gradient through the sheet thickness. In the centre layers they revealed a cold-rolling type texture (α-fibre) and close to the surface layers a strong Goss orientation. The texture maximum as well as the through-thickness texture gradient of the hot-rolled specimens increased with the Cr content. During cold rolling the textures inherited from the hot rolling process sharpened in the centre layers and decreased in the sub-surface layers. The hot band textures from which this inhomogeneity proceeded were explained in terms of the strong through-thickness profile of the shear strains. The fact that the textures were not randomized by phase transformation during hot rolling was attributed to the elevated Cr content which stabilizes the ferritic regime.

Influence of Hot Band Texture on the Development of Cold Rolling and Recrystallization Texture in Aluminium Foils

Influence of Hot Band Texture on the Development of Cold Rolling and Recrystallization Texture in Aluminium Foils

Rolling and recrystallization textures in Fe-Ni alloys

The texture evolution of Fe base Fe-Ni alloys was systematically investigated for various processing parameters. The hot bands consisted of recryslallized grains and revealed diffuse textures except for the center layer where a weak cube component developed. The cold rolling texture development was characterized. regardless of Ni content, such that the orientation densities of the texture components belonging to the β-fibre were nearly similar for a given rolling reduction and systematically increased with rolling reduction On annealing the Cube component dominated the recrystallization texture, and its orientation density depended on cold rolling reduction. These characteristics of the texture development is similar to those of pure copper. The similarity of the texture evolution in Fe-Ni alloys and pure copper is attributed to the fact that they have commonly medium stacking fault energies