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24Journal of Siberian Federal University. Engineering & Technologies, 2018, 11(4), 419-426
yflK 669.621.62.412
Large Size Metal-Clad Ingots Rolling Process Analysis Using Finite Elements Method
Vasiliy V. Yashinb, Erkin D. Beglovb, Evgenii V. Aryshensky*a and Ilya A. Latushkinb
aSamara National Research University named after S.P. Korolev 34 Moskovskoe road, Samara, 443086, Russia bJSC "Arconic Samara Metallurgical Plant" 29 Alma-Atinskaya, Samara, 443052, Russia
Received 26.01.2018, received in revised form 14.03.2018, accepted 29.04.2018
Under real rolling conditions, plastic strain is accompanied by inevitable uneven distribution of the metal movement velocities, strains and stresses both in height and width of the actual deformation zone of the rolled metal. With the simultaneous plastic strain of various metals, there is still a layered inhomogeneous strain, which is caused by the fact that at the same time in a plastic zone there are metals possessing different mechanical properties. The inhomogeneity of layered strain is one of the most important and complex problems of the theory of simultaneous plastic strain. A considerable number of works, has been devoted to the investigation of this problem, but many of the issues that we should deal with when developing the technology for the production of clad products remain unclear. In this article, the authors carried out a study of the process of rolling high cross-section ingots with cladding plates, using finite element modeling in the DEFORM software. Relationships are determined to take into account the strain inhomogeneity and the influence of various parameters on the depth of strain penetration into ingot.
Keywords: Rolling, strain, aluminum alloys, finite element modeling, ingot cladding.
Citation: Yashin V.V., Beglov E.D., Aryshensky E.V., Latushkin I.A. Large size metal-clad ingots rolling process analysis using finite elements method, J. Sib. Fed. Univ. Eng. technol., 2018, 11(4), 419-426. DOI: 10.17516/1999-494X-0064.
© Siberian Federal University. All rights reserved Corresponding author E-mail address: ar-evgenii@ya.ru
Анализ процесса прокатки крупногабаритных слитков
с плакирующим материалом
при помощи метода конечных элементов
В.В. Яшинб, Э.Д. Бегловб, Е.В. Арышенскийа, И.А. Латушкинб
аСамарский национальный исследовательский университет
им. ак. С.П. Королева Россия, 443086, Самара, Московское шоссе, 34
бАО Арконик СМЗ Россия, 443052, Самара, Алма-Атинская, 29
В реальных условиях прокатки пластическое деформирование сопровождается обязательным неравномерным распределением скоростей движения металла, деформаций и напряжений как по высоте, так и по ширине фактического очага деформации прокатываемого металла. При совместном пластическом деформировании различных металлов возникает еще и послойная неравномерность деформации, которая обусловлена тем, что в пластической зоне одновременно находятся металлы, обладающие различными механическими свойствами. Неравномерность послойной деформации является одной из самых важных и сложных задач теории совместного пластического деформирования. Исследованию этой проблемы посвящено значительное количество работ, однако многие вопросы, с которыми приходится сталкиваться при разработке технологии производства плакированных изделий, остаются еще не выясненными. В настоящей статье авторами проведено исследование процесса прокатки слитков высокого сечения с планшетами методом конечно элементного моделирования в программном комплексе DEFORM. Определены зависимости для учета неравномерности деформации и влияние различных параметров на глубину проникновения деформации в слиток.
Ключевые слова: деформация, алюминиевые сплавы, моделирование методом конечных элементов, плакированный слиток.
Introduction
Commercially produced sheets and plates of high-strength aluminum alloys (2XXX, 5XXX, 7XXX, etc.) are subjected to aluminum cladding. Researches show, that thin aluminum cladding enables complete elimination of metal edge and side walls cracking and tearing. Aluminum cladding protects aluminum alloys from corrosion, improved sheet rolling, facilitates roll bite.
Silumin clad aluminum and aluminum alloy articles can be subjected to brazing [1]. Cladding, applied in sheets and plates production, is divided into three thickness-based categories: technological, protection and construction.
Technological cladding thickness, normally, does not exceed 1,5 % of the sheet (plate) thickness, it is applied only for rolling conditions improvement.
Protective aluminum cladding thickness is 2,5-4 % of sheet or plate thickness, it protects metal from corrosion. Construction aluminum cladding thickness is 6,5-10 % of the sheet thickness; this type of cladding is an attachment material [2].
Out of all cladding materials the most rigid requirements exist for the construction cladding: it shall have specific thickness, as it determines the parts strength [3]. It is known, that with soft cladding
layer thickness increase, layerwise deformation non-uniformity increases [4]. Construction cladding distribution along the strip surface is less uniform compared to protective and technological cladding. It is especially critical for the ingots with the thickness above 500 mm. cladding thickness will be up to 28 mm in this case. The issues, associated with rolling practice development for this composition (mismatch of nominal and actual cladding thickness values, excessive blistering, non-uniform cladding layer distribution, rolling force increase with process efficiency drop due to pass reduction decrease) m-:e thistaskup-to-date: large sizemetalclad ingotsrolling practice study.
Process modelling
DEFORM software, enabling metal pressnre fonming processes; modelling usingFEM, willbe opplied for this itudiy. Modellod ex^niments veriables are listed in the Table 1.
Tho procesa fs enmmete ical, tSierefore fortneonrdoues oS thn stndy we'iS c onsidenonly tnppo rtson of the slab und u smgk tolS. ti it known, efrt snaigmficoniwidenin. (max 50 mm) occurs during 140U iieoii - ra)-)0 mm wide ingoti saUtiii-t [5]a gSt^r«oiii)re; wn'U afl UPD mnde gOT mfdelling, with 0trhrsedlsarained dih])ram - r>lottd^ ^tr^ini Griiis^nse bodh fee hadfe^ ^sid iignt is selectedbaiaden FElvtili^cr^t^sti^ii)!^, cejreti^dioiimiifi^ fa et kenl - rows in a oladpiate )nen Fig. tXQad plate is fixed to tho ingot, itn. etool niete bottom rurfacespeedttedual to tioe li^a^ol topsurfece tpeed. Roll and ia^c^^ldn^(^t^leoic;zhi]eaoei^itc^^^£iotedvai^^^t)e^a^^^ ^nozit^g^-^e^in^^^^^tjoeosi^^ withoulemoesion, with high friction coefficient ^=0,4 (Coulon law).
Rnseltr analdrle
During lugh s^efj^nsst s^lp 4"ollisig the ngufrat fin^ whl ilte meial spe^id ^quat Po the roil lineer nteiiets, has erieoed offei ilue to euniumform ^d;^orn^i^tian sFig. p Oo rhe lme rigtoieliand s)0e fie metal ^ja^tetl ls ioyvnOl tiren tin-; t(fai2^, wluk. ou tae ieeff-Pianil etide ih em lmehes.
Thi rlttlesipd chdonrs dramntical)y dnetng oil^tl iti^toil ooningi
Lai's revrnew twi oases, whrn did is not wildi fo litoiis m-lf yes. ^isaiis itage li charaetprized oy ^(^fliot^^]^ deformation, while hard layer is subjected to minor elastic deformation. Due to stretching the clad plate deformed part speedexceeds the roll speed, while non-deformed cladding plate part speed is lower, that the roll speed.Cladding platep ortion outside the strain center and attached ingot movellkr usulidbeny with lite speef euceedinothnroП Hne sen ed(en stated easlieri (Fig. 3).
Tabltl. Eaeerimnts prjai
Claddingthicknes s, mm Ingot thickness, mi Roll diametet,mm "07 * /a» Reduction, mm
D, 2 13, tn,17, 22, 25, 28 526, 5161 500,496, 492,482, 476, 470 900 0,4 10
28 470 900 1h4 20, 25, 30, 40
28 470 9(l(l, 1000, 1205, 1400 0,4 10
28 470 900 0,2; 0,3;0,4; 0,5; 0,55( 0,(5;0,7 10
*ff/ tnl - yieldstrengthofsoft(cladding) andhard (baseingot)componentsofthepackage.
Fig. 3. Speed fields during rolling of ingot with cladding plate: left - cladding plate is not welded to the ingot; right - cladding plate is welded to the ingot
In case ingot is rolled with welded cladding plate, under specific conditions, when deformation does not reach the ingot, the ingot cannot adopt the cladding plate speed on the deformation center exit, in this case either the bond is broken, or cladding plate speed is brought down to the ingot speed (due to their rigid attachment), therefore metal volume per second on the deformation center entry exceeds the metal on the exit side, causing ridge formation on the entry side (Fig. 4).
Such phenomenon causes steady rolling force increase with cladding plate thickness buildup, until maxstanddriveallowable loadis exceeded.
In order to avoid this negative effect, the reduction shall be selected to ensure compression deformation penetration to the ingot. The figures below illustrate the effect of various parameters on deformation penetration into the ingot.
Fig. 4. Ridge picture
1,05
0,9
0,85
0,8
0,75
h = 5-rl3 mm
■V V
v \
176 mm
x
\ \ \ N
W......
\
\
203 mm
h,= 17 mm
h,= 17 mm
\
' v, \
Y ^
'VV
hs=22; 25 m
28 mm
_t*_►
50
100 150
Distance from ingot surface, mm
200
250
Fig. 5. Plastic deformation penetration depth as the function of cladding plate thickness (reduction 10 mm, rolls diameter 900 mm, package thickness is 526 mm) [6]
The data, presented in Fig. 5, enable evaluating the cladding plate thickness effect on the deformation penetrationdepth inthe ingot. It is obvious, that during high ingot rolling plastic deformation does notpenetrate rhe entire ingoi tection, and its middle epction is left mtaci taolid line in the diagram shnws toe resultsof modolHngm^ironin0 withoutdad material). sn PIic case of 5-13 mm cladding plateopplicatien^oatie defpamolidn panetnates the entire ingot tMcknets, but further cladding plate tWcknese mcreaseresultr m the mgoi ptetrk; cona reduction and ramehing. With cladding plate iWckntss og tc mm and ovar sOce tt mtensity - yoeic[aOl^^t^I^iii ) along the entire ingot section
is below 1, therefore, plastic deformation does not occur in the ingot during the first pass. The cladding plate itself is significantly deformed (at constant reduction value the clad plate deformation level is in dire ct proportion to the cladding piate rhicknerr) .Such scenario causes extensive cladding plate elongation, see Fig. 6.
As follows from the diagram below (Fig. 8), reduction increase does not produce the desired effect, deformation penetrates into the ingot at 25 mm reductions only.
Fig. 6. Excessivecladding plate deformation
Distance from ingot surface, mm
Fig. 7. "Vg-H variable change depending on reduction value (ingot thickness470 mm, cladding plate thickness 28 mm,roll diameter 0000 mm)
Distance from ingot surface, mm
Fig. 8. ^'/^H variable change as the function ofwork volls diameter
Distance from ingot surface, mm
Fig. 9. Ve variable change depending on °"s/_h °s / °s
It^^ Isno^n, that work roll diameter increas e facilitate s (j^eec^r^n^^tion penetration into the ingot [7]. Fig. 9 shows deformation penetration into the ingot as function of roll diameter variability. It is seen from the diagram, that plastic deformation penetrates into the ingot (470 mm thick with up to 28 mm thick cladding plate) with roll diameterofl200 mm,and passes through the section with 1400 mm diameter.
as /
Another variobVe oC ietsrest or she cladding plate yield etrsnoth / ingotyleld sSrength s/aH (see Fig. 9), in case 2XXX, 5XXX, 7XXX type hard alloys are rolled at 400 0С this ratio may vary within 0,3^0,4 range.
Conclusion
The study covers the effect of the main rolling parameters on compression deformation penetration through the ingot section.
The min required reduction value of 25 mm is established for metal clad ingot rolling (as scalped tlhcknessis470mm, clad plate is 28 mm), with т /^=0,4 ratio and 900 mmrolldiameter.
To ensure deformation penetration into the ingot, it is recommended to use rolling mills with 1200-1400mm diamete r rollsforrollingtheingots with claddingplatesthicknessover 20 mm.
References
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[2] Король В.К., Гильденгорн М.С. Основы технологии производства многослойных металлов. М.: Металлургия, 1970, 236 с. [Korol V.K., Gildengorn M.S. Basics of multi-layer metals production technology, Moscow, Metallurgiya, 1970, 236 p. (in Russian)]
[3] Кобелев А.Г., Потапов И.Н.,. Кузнецов Е.В. Технология слоистых металлов. М.: Металлургия. 1991,248 с. [Kobelev A.G., Potapov I.N., Kuznetsov E.V. Laminated metal technology, Moscow, Metallurgiya,1991,248p. (inRussian)]
[4] Пучкова Л.М. Особенности совместной прокатки высоких слоистых полос разнопрочных металлов. Производство Проката, 2014, 9, 3-10 [Puchkova L.M. Specific features of simultaneous rolling of high section laminated metals with different hardness, Proizvodstvo prokata, 2014, 9, 3-10 p. (in Russian)]
[5] Грудев А.П. Технология прокатного производства. Учебник для вузов. М.: Металлургия, 1994. 656 с. [Grudev А.Р. Rolling technology. Textbook for high schools, Moscow, Metallurgiya, 1994. 656 p. (in Russian)]
[6] Яшин В.В., Беглов Э.Д., Арышенский Е.В., Латушкин И.А. Влияние толщины плакирующего слоя на распределение деформации по сечению слитка. IX Международный Конгресс «Цветные металлы и минералы-2017». Красноярск, 2017, 735-744 [Yashin V.V., Beglov E.D., Aryshensky E.V., Latushkin I.A. Clad layer thickness effect on deformation distribution through the ingot section. Book of papers of IX International Congress "Non-ferrous metals and minerals", Krasnoyarsk, 2017, 735-744 (In Russian)]
[7] Орлов В.К., Дрозд В.Г., Сарафанов М.А. Особенности прокатки плит из алюминиевых сплавов. Производство проката, 2016, 4, 11-16 [Orlov V.K., Drozd V.G., Sarafanov М.А., Specific features of aluminum alloy plates rolling. Proizvodstvo prokata, 2016, 4, 11-16 (In Russian)]
