Faculty: Physical Metallurgical faculty
Speciality: Processing of metals by pressure
Technology of the reception of the square-wave high-quality stocking up in smooth swingletree, named also by rolling (BKP), is concluded in that that rolled band обжимается consecutively smooths horizontal and vertical swingletree or only horizontal swingletree with кантовкой peal on 90 degrees after each passage or through one passage in all cage of the figure except clean, having calibres, corresponding to on the form and size ready renting [16, 21, 22].
Final shaping the profile of the necessary cross-section is produced in the following получистовых and clean passage by rolling in calibre. Ways to realization бескалибровой rolling
From existing and the most aplying at present follows to note the following varieties an бескалибровой rolling (BKP), differring value обжатий on passage:
The Company "Morgan Construction" (USA) is made четырехклетевой rolling mill for rolling on scheme RER bands 76 76 mms and 50 100 mms from stocking up 180 180мм in cage with чередующимися horizontal and vertical swingletree [24]. Such technical decision has reduced the size of the figure on 85% (the шестиклетевой rolling mill traditional arrangement was needed for mastering this production) [25]. At the factory Edelishtaliverk (the Hungary) works мелкосортный figure of the company SKET, consisting of 18 чередующихся vertical and horizontal cages. In five cages of the quick-and-dirty group technology BKP way BKP from stocking up 100 84 mms get the peals 52 51 mms [26]. In the following group of the cages by traditional rolling get the round profiles by diameter 8?50 mm square with side 10?41 mm, полосовые by width 20?70 mm and thickness 5?30 mm and арматурная steel by diameter 10?40 mm. In work is noted goodness of renting and essential reduction of the wear-out swingletree that raises efficiency of the functioning(working) the figure. In work [27] is noted that using to technologies BKP raises output an бездефектного renting on 8 - 10%, as evidenced by result дефектоскопии metal.
Overview information shows that in сортамент material, rolled in smooth swingletree, enter углеродистые, легированные by steels and alloys. With using BKP produce stocking up, high-quality renting form idle time, катанку and арматурные to profiles for железобетонных design. Beskalibrovaya rolling is masterred and is broadly used overseas company " Process Metallurgy ", " Scandinavian Engineering", " Morgan Construction ", "Kavasaki сэйтэцу". From square stocking up with sides from 42 before 250 mms for miscellaneous number passage (from 3 before 17) get ready renting round or square section in dimensioned range from 8 before 150 mm. is Noted that when turning from rolling in calibre on BKP, amount passage did not increase [25-29].
In Russian metallurgy for conditions acting equipment is designed technology бескалибровой rolling for figure 300-2 plants "Mosque" (g. CHelyabinsk) and figure 250/150 ON "IZHSTALI" (g. Izhevsk) without reduction сортамента figure, as well as for production of the small profiles from alloy of titanium on high-quality figure VILS (g. Moscow) and VSMPO (g. Upper Salda) [22]. Since 1991 бескалибровая rolling is used in обжимной to group of the cages of the figure 150 OAO "BMK" (g. Beloreck) [9, 19]. In all events is noted row real technical, organizing and economic advantage BKP in contrast with traditional technology [9, 11, 21, 22], however information about comparison volume of production renting in calibre and with using BKP in literature are absent. In real industrial condition square-wave stocking up production can be realized several ways, having difference both in mode of the rolling, and in composition of the applicable equipment.
According to patent [30-33] roll the band in smooth swingletree follows with initial correlation of the sides and with such обжатием to beside got peal was reached such correlation of the sides. Optimum is a correlation of the sides 2,1, but use валковой armature to special design prevents the loss to stability of the band. In patent [34] except обжатия, providing correlation of the sides of the band before and after the rolling 1,5, for prevention possible double бочкообразования is specified attitude of the diameter валка D to межвалковому clearance t, which must form. In work [35, 36] is motivated recommendations to produce deforming the band before sizes, definied from correlation b1/h1 = (1,6 - 2,6) b0/h0 at attitude D/h0 = 2,3 - 5,0 that allows to get greatly possible extraction of the band for one passage.
In patent CHSSR [37] is offered scheme of the rolling: square - a rectangle "on rib" - a rectangle "плашмя" - a rectangle "on rib" The Realization of such scheme is realized in чередующихся vertical and horizontal cage with smooths swingletree moreover before cage, in which square-wave band has a correlation , for deduction of the band were set wiring up with shaped roller. The Patent is noted possibility of the rolling the metal of any source free-play section on size.
The Similar decision is offered in work [38], where is recommended rolling the source band with correlation of the sides. Rolling is produced in up-down cage with horizontal workers swingletree, supplied at the input and on output supporting vertical swingletree moreover diameters all swingletree and distances between their axises are defined coming from height обжимаемой bands. For the reason exceptions кантовки bands when rolling the high-quality stocking up by way BKP, in work [39] is offered produce rolling in cage with cone-shaped swingletree. In lines of the figure to cages with углом of the slopping forming to axis валка 45 are interleaved with cage with углом of the slopping -45 . On patent [40] stocking up is rolled in smooth swingletree consecutively and in swingletree with rounded by bottom determined to desksides. In smooth swingletree correlation of the sides of the source stocking up forms , after rolling - (the обжатие herewith can exceed 50%). In ребровом position band is rolled from before. In work [41] is offered before rolling cage to install the неприводные a smooth swingletree (the rollers) for shaping flat galley proof on бочкообразной of the lateral surface of the stocking up that prevents their скручивание under the following rolling. The Analysis of the ways to realization to technologies бескалибровой rolling shows that practically all of these are founded on combinations of the correlation of the sides of the band at the input and output from swingletree, as well as on correlation of the diameter swingletree and sizes of renting. However, no united opinion on cause of the purpose of these correlations (recommended range of the correlations of the sides of the band, for instance, forms from 1,5 before 5,0). Not relationship mode обжатий is described with such parameter as diameter swingletree, corners of the seizure, разнотолщинность and ромбичность stocking up, ромбичность ready renting and etc.
Alongside with obvious value rolling the high square-wave bands on smooth to barrel has a row defect. In work 27, 49 are noted that band when leaving from smooth swingletree has more acute angles, than when rolling in calibre. At problem of such band in oval calibre acute angles загибаются that hereinafter brings about formation sundown. Besides, acute angles can become the reason of the forming the transverse rifts of the termal origin. The Double barrel [28], appearing when rolling the high band with low обжатиями also can bring about formation defect. The most significant defect бескалибровой rolling - low stability of the high band when rolling, insufficient изученность which restrains more broad using BKP.
As it was noted above, broad spreading to technologies square-wave band production in smooth swingletree controls beside imperfection to this technologies, from which the most essential insufficient stability of the high band when rolling her(it) in smooth swingletree. One of the founder to ideas of the using бескалибровой rolling possible to consider A.F. Golovina, noted that under due provision of stability " rolling in smooth swingletree, certainly, will displace rolling in creek" [50].
Insufficient stability of the band, characterizing change the givenned position of the band, brings about forming the differences диагоналей cross-section of the peal, to his(its) скручиванию [14, 19, 51-52]. The Problems of increasing to stability of the band in miscellaneous time were studied in work 9-11, 13-19, 21-41, 50-71, 76.
The Significant contribution to study of the questions to stability of the band at бескалибровой to rolling and ways of her(its) increasing have contributed: A.F. Golovin, I.M. Pavlov, A.P. CHekmarev, B.P. Bahtinov, M.M. SHternov, V.V. SHveykin, V.A. Tyagunov, YU.M. CHizhikov, P.I. Poluhin, B.V. Merekin, N.F. Gricuk, M.YA. Brovman, V.N., T. YAnadzava, CHzhan Veygan, V.N. Vydrin, F.S. Dubinskiy, K.G. SHikolenko, F. Fleming, V.S. Berkovskiy, V.K. Smyrna, V.A. The Awl, YU.V. Ignatovich, V.A. Haritonov, B.A. Nikiforov, A.A. The Frost, L.E. Kandaurov and other domestic and foreign researchers. The Problem to stability of the band actual for any way of the rolling, however, when rolling the high band in condition блюмингов and заготовочных figure she gains specifically important, defining importance. The Notion "high band" is given determination in work [19, 54, 72-73]. The Loss to stability on ready band is expressed by slanting of the form of the cross-section (the ромбичностью), which precede сваливание, but then rolling up [54]. In work [54, 63, 74] is brought categorization, describing condition of the band with standpoint her(its) potential energy when rolling. Stability of the band when rolling can be: - natural (if band has a minimum to potential energy) that is reached by creation corresponding to calibrations and mode of the rolling; - partial or incomplete, hanging from combination of the concrete conditions of the rolling; - artificial (at maximum of the potential energy), under which firm position of the band is reached by using special device - an валковой of armature. In majority of the studies by factor to stability of the band when rolling in smooth swingletree is ромбичность peal. For her(its) estimations and analysis under different condition of the rolling beside authors is offered several factors. On ris.1.2. are shown geometric parameters of the cross-section of the band, allowing numerically express brought below factors.
In early work on problem of stability is researched influence factor first group. A.F. Golovin [50] and V.D. Trofimchuk [77] main role loss to stability conducted source ромбичности stocking up. In more late work [54, 78, 14] выведены quantitative dependencies of the influence these factor. The Calculations on brought methods show that source quality of the stocking up, made in accordance with normative requirements [79, 80], allows to produce rolling in smooth swingletree to qualitative product not less than in five passages contract. In work [66] is noted special role of the crossbreeding the axises swingletree on origin ромбичности bands, however analytical dependencies are absent. Also follows to note that modern designs of the rolling cages, подшипниковых of the nodes, as well as methods of the checking practically exclude crossbreeding the axises swingletree. I.M. Pavlov [55] and V.E. GRUM-Grzhimaylo [81], analysing loss to stability of the bands, as prime causes bring forth the uneven heating a bullion on length and on cross-section that обуславливает the lumpy plastic characteristic and, as effect, uneven уширение. B.E. Haykin experimental studied the influence to spottinesses of the material and defect of the band on her(its) stability in centre of the deformation, however presence these factor in practice to take into account practically impossible. Besides, level of the modern development to technologies to metallurgy presence modern methods of the incoming control of the rolling allows the influence these factor not to take into account. The Authors of the many studies uniquely note the negative influence upon stability of the high band when rolling in smooth swingletree source ромбичности bands, however quantitative features in different work have a significant divergences.
The Influence factor second group on garbling the form of the cross-section of the band in literature is valued ambiguous and so, causing special interest, requires more detailed consideration. Herewith follows to take into account that their influence upon stability of the band in calibre, but consequently and on garbling the form of the cross-section of the band, as a rule, is considered not sovereign, but in complex from group factor. The Influence relations heights VWVroll up to H to his(its) width B (H/B) on ромбичность bands is considered in work [14, 31, 32, 78, 48, 82]. In enumerated work for ensuring the firm position of the band in swingletree is recommended lead rolling under H/B=1,5 2,5. In ditto time in work [33, 47] on the grounds of experimental given is done conclusion that band loses stability under Н/В 1,5. Is it Also noted that under H/B 1,5 possible double бочкообразование, providing in the most further to appearance of the wrinkles in the following passage. On patent [40] correlation of the sides of the stocking up in intermediate passage can reach V/N=3,5 6, however her(its) rolling in ребровом position must вестись with using small rounded calibre from correlation N/V=3,5..6 before correlation h/b=1,5..3,5. In work [42] recommended correlation Н/В forms 2..5. Obzhatiya, as single so and total, assignable at бескалибровой to rolling, correspond to the correlation of the sides of the cross-section of the band before and after the rolling. In work [19, 83] is described marketed modes BKP with single обжатием =46 49%. Herewith peals of the correct geometric form are received. In work [40] are recommended обжатия 60 and more percent. Together with that, studies quality metal the high bands got by rolling in smooth swingletree have shown that " обжатия must not exceed 40..45%, otherwise on free surface appear the spraining voltages, promoting development defect" [9]. On recommendation of the work [19] single обжатия must not exceed 43%.
For the reason ensuring the firm rolling the high band in smooth swingletree in work [42] is recommended at correlation of the sides N/V=2,0..5,0 produce rolling in swingletree, beside which diameter forms D=0,8Н. is Noted that alongside with goodnesses peal under such diameter swingletree by rolling before h/b=0,2..1,0 are reached value of the extraction before 2,5. In work [84] diameter D is recommended choose on empirical dependency coming from concrete sizes of the band disregarding correlations H/B. The Influence of the curvature to contact surface VWVroll up to on stability of the band, but, consequently, and on ромбичность renting is valued extremely ambiguous. If in work [14, 85, 19] is noted significant influence (but in miscellaneous degree) this factor then in [73, 75] influence of this factor is not discovered. Adjustment валковой armature is reduced to ensuring the clearance between band and holding element of armature. The Majority of the researchers [18, 14, 16, 86] suppose that clearance between free surface of the band and holding element of armature must form the minimum possible value. Critical is considered clearance, allowing stocking up to turn round for longitudal axis more then on 3 -5.
Minimizing (controlling) Mсум.отн possible to raise stability of the band. Such approach allows to calculate the value dumping moment at development mode rolling. However amount factor, influencing upon value Mсум.отн. it is limited, in particular, is not taken into account interaction of the rolled band and holding проводковой of armature.
Existing designs валковой armature for realization бескалибровой rolling As it was noted earlier, rolling the high bands in smooth swingletree is produced with using special holding wiring of armature. In work [28] is noted that "...the development mode бескалибровой of the rolling does not cause the difficulties, but reception of qualitative renting impossible without using special holding introductory проводковой of armature, providing firm position of the band when rolling". Such role introductory проводковой to armature is conducted and in study [9, 85]. The Designs проводковой armature applicable when rolling the high bands in smooth swingletree it is enough packed is described in work [91] and are characterized that that all usual requirements such as provision соосности axis of the peal with line of the rolling and prevention of the tumbling of the band for axis of the rolling, inherent traditional rolling in calibre [19, 51, 86, 91], must be executed more carefully, exactly and safely. Under traditional rolling in calibre of the high band her(its) firm position provide the lateral walls of the calibre, interacting with band right in centre of the deformation. The Absence creek under BPK is filled additional constructive element introductory проводковой armature: holding element, located right in межвалковом clearance and interacting with rolled by band, than is reached firm and stable position of the peal right in centre of the deformation.