WAYS OF UPDATING THE TECHNOLOGY
OF INDUCTION SURFACING OF THIN STEEL DISCS
Ch.V. PULKA, O .N . SHABLY, V .N . BARANOVSKY, V .S. SENCHISHIN and V.Ya. GAVRILYUK Ternopol Ivan Puluj National Technical U niversity
56 Russkaya Str., 46011, Ternopol, Ukraine. E-mail: v_gavryliuk@ m all.ru
Considered are existing technological schemes of induction surfacing of operating elements of agriculture machines. The best results are provided by continuous induction surfacing using double-loop circular inductor, heat and electrom agnetic shields, horizontal vibration and rotation of p art being surfaced. Ap plication of developed technological schemes and equipment for induction surfacing of thin disks allows increasing productivity, saving electric energy, improving microstructure, increasing wear resistance and stability of thickness of deposited layer as well as
16 Ref., 6 Figures.
K e y w o r d s : induction surfacing, surfacing consu mables, surfacing technology, double-loop inductor, heat and electromagnetic shield
Induction surfacing is based on heating and m elt ing of filler m aterial under th e effect of high-fre quency currents [ 1 —3 ]. This is th e m ost techno logical process for some types of parts due to simple equipm ent, easy surfacing process and, as a result, absence of necessity in welders w ith high qualification. In particular, induction sur facing found th e w idest d istribution in surfacing of operating elem ents of agricultural and road machines and in some other branches of national economy (Figure 1).
Considering increase of industry demands the method of induction surfacing is continuously improved in th e follow ing directions: rise of proc ess efficiency and wear resistance of deposited m etal, optim ization of induction heating modes, im provem ent of indictor structures and systems of energy saving in surfacing of disks of random diam eters and dimensions of surfacing zone.
The aim of present w ork lies in analyzing the results of researches in directions m entioned above, im provem ent of induction surfacing proc ess by exam ple of th in profiling disks of top cu t ters (Figure 1, f ) .
C ontinuous successive surfacing using seg ment inductor (Figure 2, a ) is used in production for strengthening of top cu tters w ith solid cu ttin g edge. At th a t, th e inductor is fixed to high fre quency generator and p art being surfaced is ro tated relatively to th e inductor.
The advantages of this m ethod are technologi cal flexibility and possibility of surfacing of dif ferent diam eter parts w ith com paratively small
VI h V I'til.KA, O.N. SHA1ILY, V N HAUANOVSKV, V,S. SENCIilSHIN and V.Ya.
reducing residual stresses and deformations of disks.
power. H ow ever, th is technology has relatively low efficiency and large energy consum ption. Be sides, the p art can be deform ed in surfacing, th a t effects stab ility of thickness of deposited layer and additional alignm ent operation is necessary for elim ination of disk deform ation.
The technology of sim ultaneous induction sur facing over th e w hole operating surface using surfacing w idth more th a n teeth height and dou ble-loop inductor was proposed for increase of surfacing efficiency of to p cu tters of saw to o th form (Figure 2, b ) . It resulted in 4 -5 tim es in crease of surfacing efficiency.
Loops in th e double-loop circular inductor have opposite phase connection on cu rren t and magnetic flow betw een them selves and w ith gen erator. U sing such a connection provides for for m ation of electrom agnetic field only in surfacing zone and uniform d istrib u tio n of tem perature over th e disk surface, w here charge is being m elted. However, th is technology requires sig nificant expenses of electric energy.
U pdating th e modes of pow er supply to in ductor [4] was carried ou t in order to save electric energy. It is shown th a t sim ultaneous surfacing of disks over th e w hole operating surface can be carried o u t using co n stan t specific pow er a t cer tain tim e as well as w ith its change on exponential law (energy saving m ode). At th a t, 15-25 % economy of electric energy is achieved depending on used surfacing consum ables. Thus, for exam ple, surfacing w ith sorm ite pow der PG-S1 pro vides for 15 % electric energy saving and th a t makes 23 % in surfacing using PG-AN9 powder.
W ork [5] proposed a calculation procedure for double-loop circular in d u cto r w hich provides
GAVKILYUK, 2015
5
*6/2015
A - A 0.2±0.1
Figure 1. T hin disks subjected to surfacing: a — disk cutter; b — disk saw; c, d — drive and non-drive disks for roofing slate cutting; e — knife for sunflow er cutting; f — top cu tter BMD 52425
for realizing of m ethods of sim ultaneous surfacing of profiling disks of saw to o th form over th e w hole surface by energy saving mode. A disad v antage of th is technology is th e fact th a t it can be used only for disks of specific diam eter and surfacing zone w id th . T here are cases on practice w hen diam eters of disks and w id th of surfacing zone are changed. T his requires selecting oth er stru ctu re s of in d u cto rs or special shields, th a t is rela ted w ith large financial and labor expenses.
Investigations and calcu latio n s of sizes of in d u cto rs and special shields w ere carried o u t for d ifferen t v aria n ts of ap p lica tio n of these systems, nam ely, only a t in d u c to r use (F ig u re 3, a ) \ in
d uctor and electrom agnetic shield (F ig u re 3, b ) \
inductor, h eat and electrom agnetic shields (F i gure 3, c) [6 -8 ].
D ata received as a resu lt of investigations a l lowed determ ining size of in d u cto rs and shields as well as c u rre n t for surfacing of saw to o th disks of random diam eter and size of surfacing zone, nam ely: disks of 210240 mm diam eter and 2 -6 mm thickness, w id th and thickness of deposited layer 10-50 and 1 .0 -1 .5 mm, respectively.
Thus, m an u factu rin g engineer ap p ly in g one or an o th er h eatin g system of in d u ctio n surfacing (see F igure 3 ) selects necessary d a ta g rap h ically or using th e ta b les according to disk diam eter,
F ig u re 2. Device for surfacing of all-stam ped solid cu tte r using segment inductor la) and to p c u tte rs of saw tooth form iii double-loop a r c u la r ind u cto r (b ) ( 3 1
w /////s z ffiz z
2 4
_z
Figure 3. Schemes for positioning inductors and special shields in induction surfacing: a — traditional scheme; b — inductor and electromagnetic shield; c — inductor, heat and electromagnetic shields; / — part; 2 — charge; 3 — double-loop circular indictor; 4 — heat shield; 5 — elec tromagnetic shield
w idth and thickness of deposited layer. For ex ample, th e first scheme (Figure 3, a ) requires entering seven param eters relating inductor structure and its positioning w ith respect to part, th a t reduces tim e and financial expenses for ex perim ent performance and im plem entation of new technology.
The technology proposed by authors (F i gure 3, c), particularly, allow s additional saving of 12-14 % of electric energy, increasing stability of deposited metal by 10-15 % and decreasing disk surfacing tim e from 32 to 22 s [9].
W ithin tim e a proposal was made about add ing new technological operation in induction sur facing process (Figure 4) for further increase of wear resistance of deposited m etal. At th a t, ta k ing into account small thickness of plane disks, significant attention was paid to residual stresses, deform ation and displacem ents which appear af te r surfacing in zone of operating surface having different w idth [10-13].
W ork [11] represents th e results of investiga tion of effect of additional technological schemes
o f induction surfacing on stab ility of deposited
layer thickness by four schemes. 90 % of meas urem ents of thickness of deposited layer are in tolerance range at surfacing using scheme in F i gure 4, d i th a t is 22 % more th a n in surfacing by
5
-6/2015
---scheme in Figure 4, a . In this case more uniform thickness of deposited layer is achieved due to jo in t application of horizontal vibration, heat and electrom agnetic shields as well as centrifugal forces providing uniform distribution of liquid metal in surfacing zone.
The same works show th a t maximum residual stresses g2 appear in the deposited layer directly
near the boundary of its joining w ith the base metal, and 02 = 0.54at at the boundary w ith non-surfaced zone at sormite tensile strength a t ~ - 150 M Pa [13].
The developed technology (see Figure 4, d )
allows heating w ith low level of tem perature gra dient over disk radius (Figure 5). Horizontal and vertical vibration of the p art w ith corresponding am plitude and frequency directly during surfac ing results in deposited metal m icrostructure op timizing and increasing wear resistance of depos ited layer of sormite type (PG-S1 pow der) ap proxim ately in 1.5 times.
7, °c 700 600 500 400 300 200
Figure 5. Distribution ol temperature over disk radius at the moment of deformation beginning in the base metal- deposited metal system as elastic body at different values of gradient coefficient B
RIVAL
Figure 4. Schemes of induction surfacing used during in vestigations: a — w ithout vibration of deposited part; b —
Figure 6. S u rfacin g u n it ( a ) and autom ated production system for surfacing of top cu tters ( b )
A u to m a te d p ro d u c tio n system for surfacing of to p c u tte r s (F ig u re 6 ) [ 14—16] w as developed for re a liz in g th e se tech n o lo g ies.
H ig h -fre q u e n c y g e n e ra to rs o f V C hI 6 3 /0 .4 4 , V C h G 6 - 6 0 / 0 .4 4 a n d V C h G 9 -6 0 /0 .4 4 of 60 kW p o w e r a n d 440 k H z freq u en cy w ere used for in d u c tio n su rfa c in g since base m etal thickness m ak es 2 - 6 mm.
C h a rg e co n sistin g of m ix tu re of P G -S 1 sorm ite p o w d e r a n d fl ux w as used as surfacing consu m able.
C o n c lu s io n
A pplication of developed technological schemes an d equ ip m en t for induction surfacing of th in disks allow s increasing efficiency, saving electric energy, im proving m icrostructure, w ear resistance and sta b ility of deposited layer as well as decreasing re sidual stresses and deform ations of disks.
1. T kachev, V.N. (1971) W ea r and increase in service
life o f a g ricu ltu ra l m achine parts. Moscow: Mashi-
nostroenie.
2. R yabtsev, I.A ., Senchenkov, I.K . (2013) Theory and
p ra ctice o f surfacing w orks. Kiev: Ekotekhnologiya.
3. P u lk a, C h.V . (2006) Technological and energy e ffi
ciency o f induction surfacing o f th in steel discs: Syn.
of Thesis for D r. of Techn. Sci. Degree. Kiev.
4. Shably, O .N ., P u lk a, C h.V ., Budzan, B.P. (1987) O ptim ization of pow er in p u ts in induction surfacing o f thin-w all discs. A vto m a tich . S v a r k a , 1, 36-39. 5. Shably, O .N ., Pulka, C h.V ., Budzan, B .P. (1988)
W ays of energy saving in induction surfacing of thin- w all discs. Ib id ., 12, 56-5 8 .
6. Shably, O .N ., Pulka, C h.V ., Pismenny, A.S. (1997) O ptim ization of ind u cto r design param eters for induc tion surfacing of thin steel discs. Ib id ., 6, 17-20. 7. Shably, O .N ., Pulka, C h.V ., Pismenny, A.S. (2002)
O ptim ization of inductor param eters for uniform heating of discs across the w idth of hardfacing zone allow ing for screening. The Paton W eld in g J ., 11, 23-25.
8. Shably, O .N ., Pulka, C h.V ., Pismenny, A.S. (2003) O ptim ization of induction hardfacing of thin discs al lowing for therm al and electrom agnetic shielding.
Ib id ., 9, 20-23.
9. Pulka, C h.V ., Shably, O .N ., Pismenny, A.S. (2004) Effect of induction surfacing conditions on structure and properties of deposited m etal. Ib id ., 10, 15-17. 10. Pulka, C h.V ., Shably, O .N ., Senchishin, V.S. e t al.
(2012) Influence of vibration of p arts on structure and properties of m etal in surfacing. Ib id ., 1, 23-25. 11. Pulka, C h.V ., Senchishin, V .S., G avrilyuk, V.Ya. et
al. (2013) Influence of technological schematics of induction surfacing on stab ility of deposited layer thickness. Ib id ., 4, 61-63.
12. Shably, O .N ., Pulka, C h.V ., Pismenny, A.S. et al. (1999) Residual displacem ents of thin steel discs in induction surfacing w ith w ear-resistant powder-like hard alloys. A vtom atich. S v a r k a , 9, 55-57.
13. Shably, O .M ., M ykhajlyshyn, M .S., M ykhajlyshyn, V.M . et al. (1998; M athem atical m odeling of forma tion of residual stresses, strains and displacem ents in induction surfacing of th in steel discs. V isn y k Ter-
n o p ilD T U , 3 (4 ), 5~12.
14. Shably, O.N., Pulka, C h.V . (1994) Technology and equipm ent for induction surfacing of thin shaped discs. A vtom atich. S v a rk a , 5 / 6 , 48-50.
15. Pulka, Ch.V., Gavrilyuk, V.Ya., Senchishin, V.S. (2013) Improvement or equipment and technology for induction surfacing. Svarochn. Proizvodstvo, 4, 27-30. 16. Pulka, C h.V ., G avrylyuk, V .Y a., Senchyshyn, V.S.
et al. A utom atic production line fo r surfacing o f thin
discs. P at. 94727 UA. In t. Cl. B23K 1 3 /0 0 . Publ.
25.11.2014.
R eceived 1 2 .03.2015
