CC BY
8Journal of Siberian Federal University. Engineering & Technologies 8 (2014 7) 933-937
УДК 621.777
Development of Functioning Models and Design of the Unit of Combined Rolling-Extruding for Processing of Non-Ferrous Metals and Alloys
Ivan N. Dovzhenko*, Nikolai N. Dovzhenko and Sergey B. Sidelnikov
Siberian Federal University 79 Svobodny, Krasnoyarsk, 660041, Russia
Received 14.09.2014, received in revised form 29.10.2014, accepted 15.11.2014
Analyzed the state production of long-length products from non-ferrous metals and alloys. Developed new models and proposed constructions of aggregates of combined treatment.
Keywords: metallurgy, non-ferrous metals, combined processes, rolling, extruding, modeling.
Разработка моделей функционирования и конструкций агрегата совмещенной прокатки-прессования для обработки цветных металлов и сплавов
И.Н. Довженко, Н.Н. Довженко, С.Б. Сидельников
Сибирский федеральный университет Россия, 660041, Красноярск, пр. Свободный, 79
Проанализировано производство длинномерной продукции из цветных металлов и сплавов. Разработаны новые модели и предложены конструкции агрегатов совмещенной обработки.
Ключевые слова: металлургия, цветные металлы, совмещенные процессы, прокатка, прессование, моделирование.
With the continuous technological development and globalization of markets before the enterprises producers of metal products there is acute problem increase efficiency and provide release of competitive production. This problem is especially urgent in the production of long products from non-ferrous metals and alloys in the form of rods, wire and profiles of small cross-section.
© Siberian Federal University. All rights reserved
* Corresponding author E-mail address: sbs270359@yandex.ru
Underlying of this work process of combined rolling-extruding (CRE) [1] has great potential for improving the efficiency of obtaining long products from non-ferrous metals and alloys.
Analysis of the scientific-technical and patent literature has shown that as basic for most continuous processes applies rolling, and ways to ensure the creation of active friction by movable walls of the instrument, for example, in the methods Conform, Extrolling and Lynex. Devices for the implementation of these methods work in conjunction with the aggregates of continuous casting billet, mostly rotor type. Most common in the industry have installs Holton Conform™ of company Outokumpu Holton Ltd. with wheels diameter 300, 400 and 500 mm, and also company BWE Ltd. Conform™ and Conklad™ with wheels diameter 285, 315, 350, 400, 550 mm and drive power from 100 to 500 kW. The maximum diameter of the billet is 25,5 mm from aluminum and 22 mm from copper. Approximately 75 % of working units Holton Conform™ intended for obtaining of aluminum products and 25 % from copper and copper alloys.
Despite the advantages of these units should be noted and shortcomings of the method Conform: high energy intensity of the process, as the costs of overcoming the friction forces on the surfaces of instrument assembly require for drive the use electric motors of high power; unevenness of deformation; sufficiently complicated construction of press unit and its cooling system. Thus, the driving power of installation CRE comparing to installation Conform at comparable diameters of the rolls and wheel lower for 3-4 times.
For the process CRE performed a complex of theoretical and experimental research, implemented protection of technical solutions in the form of patents, established pilot installations based on the rolling mills. However, there is a need of development constructions of industrial aggregates CRE as objects of modular continuous technology taking into account the advantages and lacking disadvantages of pilot units.
The analysis showed that the design of industrial aggregates CRE as objects of module technologies need to develop their structural and parametric descriptions using a set of project parameters and operational models.
One of the main factors determining the energy-power parameters of the process CRE is the coefficient of extraction during extrusion, and therefore were performed experimental studies on the installation CRE-200 for an alloy of lead with antimony, aluminum and its alloys and copper. On Figure 1 represented typical for the process CRE dependence of the forces on the matrix, rolls and moments (further index 1 - relates to roll with a ledge, index 2 - with cutting) during deformation in hot conditions at 470 0C of aluminum A7 in various calibers. Analysis of experimental data revealed the following general patterns of the process CRE: increase extraction increases the forces on the matrix which is characteristic of the extrusion process, and on the rolls due to increased boost pressure in the deformation zone from the force of extrusion; reduction in cross-sectional area of caliber at one and the same extract reduces the forces on the matrix; change in the force on the rolls is very sensitive to changes in the extrusion force; moment on the roll with cutting more than moment on the roll with a ledge, due to the difference in the contact area of the walls caliber with billet during deformation; there is a correlation relationship between the moments on the roll with a ledge and roll with cutting, and the rate of change AM2 / AM higher for of hot deformation conditions for alloy AD31 and copper than lead.
b
Fig. 1 Dependence of the forces on the matrix f„ and rolls Pr (a) from extraction X during extruding the alloy A7 (1 - Pr, and 2 - Pm, caliber 13x22 mm; 3 - Pr and 4 - Pm , caliber 11x15 mm) and moments on the rolls M1 and M2 (b) with the same parameters (1 -M2 and 2 -Mu caliber 133x22 mm; 3 -M2 and 4 -M1; caliber 11x15 mm)
a
For process CRE implemented on the rolls of different diameters found that the length of the arc of capture, the pressure on the rolls, zoiie sizas crimping under the rolls and moments on the rolls are not the same.
For the calculation temperatuae of press-article to the development solution of J.L. Sternik on the basts oa one of the pnoperties of fntegrals of the differential equaeion Fourier to accouct for the nwo-dimensional heao flow in fhe billei deeormatinn in the borm of bar and substitution of rheamal characteristics fortht alloy AD3f following equation was obtained
T^ = To + 0,315 ) + A-^ + A^ r -a AT ^ -
-2^ +0,315 (AT^ + A^ ) + A( - TK ] ■• [d- rxp (-., 5tlNulPe)),
where T0 -biflet temperature,/:>«==<TXlrtd^Xe+^nX) -psessure of extruding, 3l- exteac(ion coefficient during extrudiing, Arroe AT, c and ATfi - rema5sature ^nc;io<SiEi^e:r accoidingey from deformation during riling, decomprersion mnd friction on the wails of catiber, Pe=vht/a - Ieeec;^ei^ number, Nu=lAlh0 -Nusselt number, y=Atrme/(0+iVMPe), a - coefficienr tof tire-mal diffusiviCy, e. - average velocity of recfions in the deformation zone v=2fflr?1R2/(R1+ri! 2), and to - rotafimnal rpeed oftrine rolls.
For condition, R)=2 10 t^m, R2=18 0 mm, ,= 155,1, 70=480 °C (ii^lo^y AD31) results of caecutation by the above formula is shown in Fig. 2.
Analysis oh simulation results showed, that wsth increasing rotational speed of the rolls of heat transfer time is reduce d between she metal of billet and rolls. Accordingly decreases temperature drop in the billet of rolling and decompression zones which increases the product temperature at the outlet of the matrix.
Based on the results of studies proposed to use for aggregates CRE:
- box-like frame with console emplacement of rolls, diameter from 100 to 300 mm, providing rapid tool changing (rolls and matrix) to produce small batches of deformable alloys (aluminum A^,1, silver SAg40 etc.) with the wide nomenclature;
- closed frame (the diameter of the work rolls 400 or 500 mm), providing greater stiffness and is designed to operate using a large cross-section billets with high performance, and also allows
r ^c
525
_>UU 475 450 425 400 s
4
2
:i : . f, \ i: i: M :■■:■:■■ .■■■■
Fig. 2 Calculated dependence ofthe temperature of the product Tprod output from the matrix of the speed of rolls n and temperature of the; roll s T„f 1 - 150 °C; 2 - 200 °C; 3 - 2250 °C; 4 - 300 °C; 5 - 350 °C
Fig. 3 Configuration solution of aggregate CRE-300 (a) and construction of a combined unit of gear cage with console tolls (h): 1 - tontole roll; 2 - frame; 3 - bearing; 4 - sealing; 5 - east coupling; 6 - gear wheel; 7 - matrix
proces sing hardly-deformable alloys of aluminum and coppeo. Voaiant configuration sofution of aggeegate CRE-300 of frame type presented on Fig. 3.
The; design of roll is combined using hard alloy ring and mounting system of company «Kark». Further, this version of the unit has been improved through the use of design combined unit gear cage with console rolls (Fig. 3b).
As a drive of tfe -wo rk rolls proposedto use modern motor reduoers o r hydraulic motfg reduce rs does not require addigional reducers wWch significantly reduces the overall dimensions of the unit CRE. For the production of press-articles from billets with a cross section 40*40 mm and more from aluminum alloys and copper developed construction of aggregate CRE-400 with the initial diameter of the rolls 400 mm (Fig. 4). As an analog of roll block is taken cage section rolling mill of construction USTU-UPI (Yekaterinburg).
Therefore, developed models and proposed the construction of aggregate CRE-400 which ensures that no overturning moment through the use of individual drive for each roll, high stiffness of system roll-matrix block and reliability. The results of the studies were used to create a physical model of the installation of combined processing for the production electrotechnical wire rod.
21 16 4 12 ~*1 1 J
b
Fig. 4 The construction of aggregate CRE-400 (a) and cross-section in the plane of work rolls (b)
References
[1] Sidelnikov S.B., Dovzhenko N.N., Zagirov N.N. Combined methods of treatments of non-ferrous metalo and alloys. Mo MAKS Press, 2005. P. 344.
