scholarly journals Development of Deformation Texture in Aluminum Sheets during Asymmetrical Rolling with a Roll Speed Ratio of 1.5/l.0

2003 ◽  
Vol 12 (3) ◽  
pp. 244-250
2021 ◽  
Author(s):  
Ji Wang ◽  
Xianghua Liu

Abstract A new model for the asymmetrical rolling is proposed to calculate the minimum rollable thickness simply and fast by the slab method. The calculation formulas of the rolling pressure, the rolling force, the critical roll speed ratio and the critical front tension under different deformation zone configurations are proposed, and the deformation zone configuration - rolling parameters relationship diagram is given and analyzed. The results show that the minimum rollable thickness can be reached when the rolling parameters keep the deformation zone configuration as cross-shear zone + backward-slip zone (C+B) or all cross-shear zone (AC). The calculation formulas of the minimum rollable thickness and the required rolling parameters for different deformation zone configurations are proposed respectively. The calculated value is in good agreement with the experimental results.


2005 ◽  
Vol 495-497 ◽  
pp. 597-602 ◽  
Author(s):  
Tetsuo Sakai ◽  
K. Yoneda ◽  
S. Osugi

Large shear deformation was successfully introduced in 5182 aluminum alloy sheets by 2-pass differential speed warm rolling under a high friction condition. The roll speed ratio was varied from 1.0 to 2.0. When the roll speed ratio was smaller than 1.4, shear strain increased near the surface, but the strain decreased to zero at the mid-thickness. At a roll speed ratio larger than 1.4, shear strain was introduced even at the mid-thickness, and it increased near the surface. Thus the shear strain increased with the roll speed ratio. After 2-pass differential speed rolling, a large shear strain prevailed throughout the thickness. The rolling direction of the second pass was so selected that the direction of shear deformation introduced in the second pass was similar to (unidirectional shear rolling) or opposite (reverse shear rolling) that in the first pass. A shear texture with main components of {111}<110>, {112}<110> and {001}<110> prevailed throughout the thickness, and conventional rolling textures such as {112}<111> or {123}<634> orientation were not detected in any part of thickness. The rolling direction of the second pass had little effect on the deformation texture. After recrystallization annealing, the shear texture components were retained. The intensity of the shear texture components after recrystallization was almost similar to the deformation texture. The r-value of the annealed sheet was slightly increased and the planar anisotropy of the r-value was decreased by differential speed rolling. Differential speed rolling, by which shear deformation can be introduced throughout the thickness, was thus shown to be a promising process for improving the physical and mechanical properties of rolled and annealed aluminum alloy sheets by texture control.


2008 ◽  
Vol 22 (31n32) ◽  
pp. 5661-5666
Author(s):  
SHINIL KIM ◽  
CHENG LU ◽  
XIAOZHONG DU ◽  
ANH KIET TIEU

In this paper an explicit dynamic finite element method model has been developed to investigate the strip deformation behavior between two adjacent stands in hot finishing mill. The effect of the roll speed ratio of second stand to first stand on tension and the tailing behavior of the strip has been discussed in details. It has been found that the strip accumulation occurs if the roll speed ratio is small. The tensile stress increases with the roll speed ratio. During the tailing process the accumulated strip caused by the small roll speed ratios knocks onto the roll, while the swing of the strip tail occurs for the large roll speed ratios and it strikes the roll as well. Both tailing phenomena will result in the strip tail pincher or roll damage in the real operation.


Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 891 ◽  
Author(s):  
I Widiantara ◽  
Hae Yang ◽  
Muhammad Kamil ◽  
Dong Yoon ◽  
Young Ko

The work looked into the grain refinement process of Mg alloy during asymmetrical rolling with a focus on the role of twin. The present sample was deformed at ambient temperature by single operation with the height reduction of 50% at the roll speed ratio of 1:4 for the upper and lower rolls having the same dimension. From the electron backscatter diffraction analysis in the surface region where intense shear strain was imparted, a number of { 10 1 ¯ 2 } extension twins with a width of ~1 µm were detected clearly in most of the deformed grains. Moreover, the average misorientation angle of the deformed grains in the top region was found to be ~32°, which was two times higher than that in the center area where the extension twin was detected rarely. As a result, the microstructure in the top region was refined significantly down to be ~1.1 µm with an aid of twin activities that would be discussed in this study.


2020 ◽  
Vol 21 (5) ◽  
pp. 525
Author(s):  
Pujun Hao ◽  
Jingna Liu

Most asymmetrical rolling conditions should not appear in regular rolling processes, but for obtaining large deformations inside aluminium alloy thick plates, the asymmetrical rolling process is the most effective method. Snake rolling is adopted for promoting more deformation inside the plates. For exploring the deformation inside an aluminium alloy thick plate, a finite element model for simulating the process of snake rolling is established and the key influence factors are set as initial thickness, speed ratio and offset distance. The results show that deformation inside of the plate increases obviously while the thickness of plate is less than 300 mm after snake rolling. The speed ratio has a positive effect on promoting deformation partly inside of the plate. On the contrary, the offset distance has a negative influence by affecting the exit thickness. A formula for calculating the exit thickness after snake rolling is proposed and validated by data from the finite element models. Thus, snake rolling is suggested to be used in the downstream pass of hot rough rolling considering that the influence of thickness and the offset distance should be controlled in a reasonable range.


2010 ◽  
Vol 636-637 ◽  
pp. 538-543 ◽  
Author(s):  
Denis Solas ◽  
Sorphal Chhann ◽  
Thierry Baudin ◽  
Richard Penelle

Asymmetrical rolling, in which the circumferential velocities of the working rolls are different, is a method to impose shear deformation in addition to the thickness reduction. As a consequence, the deformation texture can be modified as compared to the classical rolling. In this work, the asymmetrical rolling of invar (Fe-36%Ni) and the influence of the deformation route are studied. The Invar® alloy has been deformed by asymmetrical rolling with a 83% thickness reduction. The texture of the deformed alloy was measured by X-ray diffraction at different levels through the thickness: upper side- middle- down side. With asymmetrical rolling, the deformed texture is a copper type texture but the components were rotated about 5-7° around the Transverse Direction (TD) axis as compared to the ideal position of these components in the pole figure representation. The rotation of the pole figure is an indicator of the amount of shear really introduced in the material during asymmetrical rolling. Finally, a simple model was developed in order to establish the condition to obtain either shear texture or grain refinement.


2010 ◽  
Vol 97-101 ◽  
pp. 2955-2960
Author(s):  
Xiao Zhong Du ◽  
Quan Yang ◽  
Zheng Yi Jiang ◽  
Xiao Ping Zhang ◽  
Xiao Chen Wang

Asymmetrical rolling is usually used on some special rolling produce. It offers lower rolling pressure, more reduction and better crystallographic textures. In recent years asymmetrical rolling has become more important due to realization of improved properties of the strip. In this paper, a elasto-plastic finite element method code has been developed to simulate the asymmetrical rolling of strip, considering unequal roll radii, unequal speed ratio between the upper roll and lower roll, different exit thickness and different reduction. Meanwhile, The profile, crown and edge drop of strip, as well distribution of front tensile stress were discussed in different rolling process. It makes better preset values for the online control system and good results was obtained.


2020 ◽  
Vol 588 ◽  
pp. 119770
Author(s):  
Busayo Olaleye ◽  
Chuan-Yu Wu ◽  
Lian X. Liu

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