The effect of roll roughness on the rolling parameters during cold rolling of an aluminum alloy

Lenard, John

doi:10.1016/j.jmatprotec.2004.03.026

Cited by 30 publications

(23 citation statements)

References 18 publications

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“…For the comparison to the predictions of the models the results of experimental strip rolling made by Lenard [19]. The details of these are described here briefly for completeness.…”

Section: Experiments 31 Equipmentmentioning

confidence: 99%

“…The temperature-viscosity parameter is calculated as 0.0176 °C-1. Earlier work with this lubricant, while rolling commercially pure aluminum strips using rolls of 0.18 mm R a roughness and placing ten drops of the lubricant on each side, indicated that under most circumstances sufficient amounts of oil were entrained and were able to cause decreasing loads on the rolling mill as the speeds were increased (Lenard [19]). …”

Section: Materials and The Samplesmentioning

confidence: 99%

“…Eq. (1) and (2) indicate the functional relationships of the coefficient of friction and the friction factor, as dependent on ∆v, respectively: Both the coefficient of friction and the friction factor are chosen such that the roll separating forces and the roll torques are all computed accurately and the difference between the predictions and the experimental data of Lenard [19] is minimized. In a separate set of similar calculations, the friction factor is also determined.…”

mentioning

confidence: 99%

“…Fig. 1 The multipliers of the coefficient of friction and the friction factor, determined using the FEM and the inverse approach [19] The coefficient of friction and the friction factor are known to depend on the relative velocity between the roll and the rolled strip and the reduction in a similar manner: both drop as the relative velocity and the reduction increase. The effect of the increasing relative velocity is due to the increasing amount of lubricant drawn into the contact zone while the effect of the increasing reduction is felt through the increasing viscosity of the lubricant.…”

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confidence: 99%

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A Comparative Evaluation of Predictive Models of the Flat Rolling Process

Szűcs

Krállics

Lenard

2018

Period. Polytech. Mech. Eng.

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IntroductionThe success of a mathematical model is judged by the consistency and the accuracy of its ability to predict the variables in the rolling process. Usually these include the roll separating force and the roll torque, determined in carefully controlled experiments. Of the two criteria mentioned above, consistency of the predictive ability is the more important, since sometime accurate predictions are essentially useless. There are many modelling methods published in the technical literature that allows to study the flat rolling process like the empirical models, the one-dimensional models, the upper-bound models and the finite element analysis computing numerous parameters.The empirical model presented by Schey [1] calculates the roll separating force by adjusting the compression of the strip to account for interfacial friction and the relative motion between the roll and the strip. The Hitchcock formula is used for taking into account the roll deformation and it requires an iterative approach. The rolled strip is modelled as rigid -ideally plastic material with isotropic hardening behaviour.The one-dimensional model assumes the presence of plane strain flow, the homogeneous compression to predict the rolling force and torque. For the Bland and Ford's model is widespread to study the cold rolling process [2] The model requires to make several assumptions and simplifications reducing the complexities and allowing the closed form integration of the equation of equilibrium. In the model proposed by Roychoudhuri and Lenard [3] the flattening of the work-roll is taken into account using the two-dimensional theory of elasticity. The strip behaves like an elastic-plastic material which also added a further element of reality to the analysis. In the above mentioned models the coefficient of friction is treated as constant continuously during the rolling process.The upper-bound approach that predict the power required for the steady-state process was also used in the analysis of the flat rolling process [4]. In most treatments the rolls are taken to be rigid and the rolled strips are rigid-ideally plastic, the friction factor is employed constant.Finite-element method provides the opportunity to exam the flat rolling process in details thus numerous applications

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“…For the comparison to the predictions of the models the results of experimental strip rolling made by Lenard [19]. The details of these are described here briefly for completeness.…”

Section: Experiments 31 Equipmentmentioning

confidence: 99%

Section: Materials and The Samplesmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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A Comparative Evaluation of Predictive Models of the Flat Rolling Process

Szűcs

Krállics

Lenard

2018

Period. Polytech. Mech. Eng.

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“…The restoration processes can change microstructures as well as mechanical and physical properties of metals and alloys while required mechanical and physical properties may be achieved by adjusting the deformation and annealing variables. 2 Some of the researchers [3][4][5][6] studied about cold rolling of various aluminum alloys. D. Wang et al 3 studied about severe cold rolling (CR) deformation properties of AA 7050.…”

Section: Introductionmentioning

confidence: 99%

Analysis of twin-roll casting AA8079 alloy 6.35-μm foil rolling process

Can¹,

Arıkan²,

Çinar³

2016

Mater. Tehnol.

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In this work the rolling process and properties of a 6.35-μm twin-roll casting AA8079 aluminum alloy foil was analyzed. First, the 8-mm-thick sheets were produced with a twin-roll casting technology. This product was annealed and cold rolled to a 6.35-μm foil with suitable processing conditions. The mechanical tests and microhardness measurement was applied to specimens derived from all the foil-rolling process stages. On the other hand, the specimens' surface roughness and the surface structure are visualized with an atomic force microscope and an SEM. The microstructural investigation is realized with an optical microscope and XRD. The von-Misses total effective strain was calculated by determining the incremental work for all of the cold-rolling cycle. The alloy showed very low ductility in the tensile tests because of the second-phase metastable intermetallic particles such as Al3Fe. The maximum elongation at the breaking value was measured for 256-μm-foil as 4.5 %. On the other hand, the alloy did not show any significant strain hardening after the cold rolling during the plastic-deformation stages. Keywords: aluminum foil, cold rolling, twin roll casting V delu je bil analiziran postopek valjanja in latnosti 6,35 folije iz AA8079 aluminijeve zlitine, ulite med dvema valjema. Najprej je bil izdelan 8 mm debel trak po postopku ulivanja med dvema valjema. Trak je bil primerno`arjen in hladno zvaljan v 6.35 μm folijo. Iz vseh stopenj procesa valjanja so bili vzeti vzorci na katerih so bile dolo~ene mehanske lastnosti in izmerjena mikro trdota. Poleg tega je bila hrapavost povr{ine in struktura povr{ine vizualizirana z mikroskopom na atomsko silo (AFM) in iz SEM. Preiskava mikrostrukture je bila izvr{ena s svetlobnim mikroskopom in z rentgensko difrakcijo (XRD). Za dolo~anje stopnjujo~ega dela, med celotnim ciklom hladnega valjanja, je bila izra~unana celotna von-Misses efektivna napetost. Zlitina je pokazala zelo nizko duktilnost pri nateznih preizkusih zaradi vsebnosti delcev sekundarne metastabilne intermetalne faze Al3Fe. Maksimalni raztezek pri poru{itvi je bil pri 256 μm debeli foliji 4.5 %. Po drugi plati pa zlitina ni kazala nobenega ob~utnega napetostnega utrjevanja med posameznimi fazami plasti~ne deformacije. Klju~ne besede: aluminijeva folija, hladno valjanje, ulivanje med dvema valjema

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