Papers by Keyword: Thin Strip

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Authors: Ryoji Nakamura, Kenta Takahashi, Masahiko Ikawa
Abstract: An unequal diameter twin roll caster was devised in order to increase productivity of the strip. This caster could cast the strip thicker than 6mm at the speed of 5m/min. The feature of this caster is that the lower roll was four times larger than the upper roll. The solidification length of the strip could be set longer easily than the conventional twin roll caster for aluminum alloy. Lowsolidification rate semisolid casting and low superheat casting were adopted. These were effective to increase the casting speed without decreasing the thickness of the strip. In the present study, the unequal diameter twin roll caster was designed and assembled. The test castings were operated and the characteristics of this caster were shown.
145
Authors: Zheng Yi Jiang, Xiao Zhong Du, Yan Bing Du, Dong Bin Wei, Xiao Feng He
Abstract: The demand of thin gauge strip with good quality such as the strip shape and surface finish is significantly increasing. In this study, finite element model of the strip shape during cold rolling of thin strip in asymmetrical rolling was developed, and the finite element simulation of the thin strip shape has been carried out in LS-DYNA. The effects of reduction and speed ratio on the strip shape and profile and the strip edge drop have been obtained. The developed finite element model has been verified with the experimental data. The obtained results are applicable to the control of the rolled thin strip shape in rolling practice.
206
Authors: Hai Bo Xie, Zheng Yi Jiang, Dong Bin Wei, A. Kiet Tieu
Abstract: Cracks in metal product significantly decrease quality and productivity of the rolled thin strip. In this paper the stress intensity factor (SIF) solution of edge crack defect of thin strip during cold rolling was investigated, and a globe analysis was applied to the problem of free edge of thin strip. The effective stress intensity factor range is important because it represents the major physical cause of crack growth. The present study provides insights of the mechanics of edge crack growth that has been frequently observed during thin strip rolling. The efficiency and reliability of the SIF analytical modelling has been demonstrated. The proposed method for predicting edge crack is useful for producing defect-free products in rolling, and provides insights of the mechanism of edge crack growth.
222
Authors: Zheng Yi Jiang
Abstract: In this paper, finite element models of the strip shape during cold rolling of thin strip in both symmetrical and asymmetrical rolling cases have been successfully developed, and the effects of rolling parameters on strip shape such as the thickness distribution along the strip width have been obtained. The strip edge drop and shape are discussed under both symmetrical and asymmetrical rolling conditions. Simulation results show that the asymmetrical rolling can reduce the strip edge drop dramatically, which is useful in improving the strip shape and reducing the energy cost during cold rolling of thin strip. The developed finite element model has been verified with the experimental value. The obtained results are applicable to control the rolled thin strip shape in practice.
2980
Authors: Abdulrahman Aljabri, Zheng Yi Jiang, Dong Bin Wei
Abstract: Strip profile control during rolling is required to assure the dimensional quality of rolled thin strip is acceptable for customers. Throughout rolling, the strip profile is controlled by using the advanced shape control rolling mill, such as the combination of work roll crossing and shifting during asymmetrical rolling, the one of the valuable methods to control the strip profile quality in rolling process. In this paper, the influences of cold rolling parameters such as the crossing angle and axial shifting value of work rolls on the strip profile are analysed. The strip shape control is discussed under both symmetrical and asymmetrical rolling conditions. The obtained results are appropriate to control the rolled thin strip profile in practice.
212
Authors: Abdulrahman Aljabri, Zheng Yi Jiang, Dong Bin Wei
Abstract: Cold rolled thin strip has received a great deal of attention through technological and theoretical progress in the rolling process, as well as from researchers who have focused on some essential parameters of strip such as its shape and profile. This paper describes the development of a 3-D finite element model of the shape of thin strip during cold rolling to simulate the cold rolling of WCS (work roll crossing and shifting) in asymmetric rolling. This finite element model considers the asymmetrical rolling parameters such as variations in the diameters of the rolls and the crossing angle as the work roll shifts on the strip during cold rolling. The shape and profile of the strip are discussed in the asymmetrical and symmetrical rolling conditions, while the total rolling force and distribution of stress are discussed in the case where the roll cross angle and axial shifting roll changes. The results can then be used to control the shape and profile of thin strip during rolling.
515
Authors: Ryoji Nakamura, Hisaki Watari, Shinji Kumai
Abstract: Two kinds of roll casters, which were suitable for high speed roll casting, were devised. One was a vertical type twin roll caster, and the other was an unequal diameter twin roll caster. The semisolid roll casting using a cooling slope was adopted to these roll casters. The solid fraction was smaller than 5%. 3 mm thickness of 6111 strip was cast at 60 m/min by the vertical type twin roll caster, and 5 mm thickness of 6111 strip was cast at 30 m/min by the unequal diameter twin roll caster. The microstructure of the as-cast strip was equiaxed and spherical, not columnar. The mechanical properties of the strip rolled from roll-cast strip were almost as same as that of the strip made from cast ingot.
343
Authors: Ryoji Nakamura, Shinsuke Suzuki
83
Authors: Zheng Yi Jiang, Hong Tao Zhu, Dong Bin Wei, A. Kiet Tieu
Abstract: Asymmetric rolling is used to produce thinner strip, which can reduce rolling force significantly. When a thinner strip is rolled on a rolling mill, work roll edge may contact each other, which affects the mechanics of this special asymmetric rolling and the crown of the rolled strip. In this paper, the authors developed a numerical model to simulate this special rolling and obtained the rolling force, intermediate force, roll edge contact force, the crown of the rolled strip and the edge contact length. The effects of the initial thickness of strip and the friction variation at upper and lower work rolls on the rolling force and crown of the rolled strip are also discussed.
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