CA2051221C - Method of manufacturing a bimetal casting and wearing part produced by this method - Google Patents
Method of manufacturing a bimetal casting and wearing part produced by this methodInfo
- Publication number
- CA2051221C CA2051221C CA002051221A CA2051221A CA2051221C CA 2051221 C CA2051221 C CA 2051221C CA 002051221 A CA002051221 A CA 002051221A CA 2051221 A CA2051221 A CA 2051221A CA 2051221 C CA2051221 C CA 2051221C
- Authority
- CA
- Canada
- Prior art keywords
- inserts
- insert
- casting
- ferrule
- crusher
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D19/00—Casting in, on, or around objects which form part of the product
- B22D19/08—Casting in, on, or around objects which form part of the product for building-up linings or coverings, e.g. of anti-frictional metal
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
- B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
- B02C13/00—Disintegrating by mills having rotary beater elements ; Hammer mills
- B02C13/26—Details
- B02C13/28—Shape or construction of beater elements
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
- B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
- B02C15/00—Disintegrating by milling members in the form of rollers or balls co-operating with rings or discs
- B02C15/004—Shape or construction of rollers or balls
- B02C15/005—Rollers or balls of composite construction
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
- B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
- B02C4/00—Crushing or disintegrating by roller mills
- B02C4/28—Details
- B02C4/30—Shape or construction of rollers
- B02C4/305—Wear resistant rollers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D19/00—Casting in, on, or around objects which form part of the product
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D19/00—Casting in, on, or around objects which form part of the product
- B22D19/06—Casting in, on, or around objects which form part of the product for manufacturing or repairing tools
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B28—WORKING CEMENT, CLAY, OR STONE
- B28D—WORKING STONE OR STONE-LIKE MATERIALS
- B28D1/00—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor
- B28D1/18—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor by milling, e.g. channelling by means of milling tools
- B28D1/181—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor by milling, e.g. channelling by means of milling tools using cutters loosely mounted on a turning tool support
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
- B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
- B02C2210/00—Codes relating to different types of disintegrating devices
- B02C2210/02—Features for generally used wear parts on beaters, knives, rollers, anvils, linings and the like
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Food Science & Technology (AREA)
- Manufacturing & Machinery (AREA)
- Mining & Mineral Resources (AREA)
- Crushing And Grinding (AREA)
- Component Parts Of Construction Machinery (AREA)
- Earth Drilling (AREA)
- Adornments (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Crushing And Pulverization Processes (AREA)
- Lubricants (AREA)
Abstract
The method consists in casting an insert in a first mould, in disposing the insert thus cast in a second mould and in casting the part in this second mould around the insert in such a way as to form a mechanical bond between the two castings.
The wearing part thus cast advantageously comprises an insert having a high resistance to wear while the rest of the part is made of a more ductile material which is resistant to mechanical stresses.
Application to crushing wheels and to crusher hammers.
The wearing part thus cast advantageously comprises an insert having a high resistance to wear while the rest of the part is made of a more ductile material which is resistant to mechanical stresses.
Application to crushing wheels and to crusher hammers.
Description
2~22 ~
M~thod of manufacturinq a bimetal castinq and wea~inq part Produced by thi~ method The pre~ent invention relates to a method of manufacturing a bLmetal casting and a wearing part produced by this method, particularly ferrules and crusher hammers.
Many wearing parts, for example in the field of c~ushers, are ~ub~ected to high m2chanical ~tresses in the mass and to high wear by abrasion on their working ~urface, ~uch that it i~ desirable that these part~
should have a high resistance to abra~ion and a certain ductility to be able ~o re~ist mechanical ~hock stre~e~, and po~sibly to be able to be machined. Now, it i~ well known that these propertie~ are not compatible. I~ i~ of 15 course pos3ible to choose a steel exhibiting a c~~,- ;~e between these two oppo ite properties, but this mUct necessarily be done to the detriment of re~i~tance to wear or of ductility.
In order to avoid ~uch compromi~es, it i~ known to produce composite part in which the ~ection expo~ed to abrasion i8 con~tituted ~y ferrochrom$um with a high re~istance to abrasion ~upported by a core made from a more ductile steel. Thi~ allows the w~ar of the part to ~e reduced while allowing the core to be machined and avoidin~ its bre~k~ge during this operation. Purther-more, it i~ posslble to reduce its manufacturing cost b~
a ~udiciou~ choice of it~ c ~-~nts.
Several man~~acturing method~ of such c~~ , 6ite or bLmet21 parts are known. ~hu~, for example, the ~ 30 Patent ~V-64303 propo~es a manufacturing method for : c J3ite par~3 by ~uccessive ca~ting~ of material~
~ having di~ferent or comple~entary properties. ~his : techniqu~ however has two re~triction~. Firstly, tha : method necessarily implies the exi~tence of a horizontal separating ~urface between the two cast metal Further-more, tha casting mu~t be relatively massive to allow the ~ucces~ive ca ting of th~ two metal~ while obt~ining 2 correct metallurgical bond be~ween ~hese m~tal~. The~e two restri.ction~ lLmit the field of applica~ion of the , ~.. . , , ., ., . . :
.. . '' ' ~ ' . ' ',' '' ' ' ' ~ - .. . . ..
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, .: . . . , . -, , . ~ '' ,, ~ 2 - ~0~22~
~olution proposed by the abovem~ntioned pat~nt.
It i~ also known to produce bimetal wearing part3 by welded assembly. A1though, in theory, a welded assembly does not have 1Lmits at the level of -the mor phology of the components to be assen~led~ in practice such li~its exist and they depend on th~ welding m~thod used. Furthermore, all welding method~ applied to fragile materials require a perfect control o~ their h~ating and cooling cycle, and a very accurat~ position-in~ of the surfaces to be as~e!mbled. The result of this i~ that a welded assemb1y is a relatively expen~ive ~echnique and is of limited applica~ion.
It is also known t~ produce bimetal partq by brazed assembly. Thiq technique offers the possibility of assembling components Of ~ariou~ hapes, but it ~till reguire~ a very accurate machin;ng of the contact ~ur-face~ and positioning devices which are alqo very accu rate.
High tempera~ure brazing offers mechanical p.o~e~Lie~ comparab~e with welding, but it requireq meticulous oper~ting precaution~ and the use of special furnaces, particularly vacuum furnace~, if its i~ deqired to obtain a rellable assembly. ~hiR results in a rela~
ti~ely high manufacturing co~t.
With regard to low temperature brazing, ~ust lik~
glueingJ it is certainly le~s ~xpensilTe but the mechan ical characteris~ics of the assembly are distinctly inferior and e~en insuf~icie~t for highly ~tre sed ; wearing part~.
The e variou~ t~chniqu~ are in par~icular le-- -n~d by the do~ EP-A~-0,271,336 for th~
manufacture of crusher ferrule~. ~he surface of Yuch a ferrule i~ expo ed to hi~h tension3 which generate crack~
propaga~ing ~hrough ~he ~uQpo~l~ O~ the ferrllle in order to render the latter rapidly usele~s.
The Pal;ent US-4, Og9, 988 propc)ses the u-~e of th~
technique of insert3 for the production o bimetal armour plates, for. }~la~t fur~ace~. According to this patent, in erts are f ir~tly ca~t in ~ir~t ~ould~, these i~sert~
.
. ~ . .. ~ .
CA 020~1221 1998-01-29 are then pl~ced in a second mould into which the part is cast around the inserts in order to form a metallurgical bond between the inserts and the support material. This method has the disadvantage that the inserts undergo thermal shocks during the casting of the parts. The thermal shocks generate internal tensions and cracks which propagate not only through the inserts but, because of the metallurgical bond, also through the support.
This disadvantage appears to a greater degree when the insertion rate is high, that is to say when the mass of the inserts is relatively large with respect to the mass of the support as in this case it is necessary, in order to ensure the formation of the metallurgical bond during the casting of the part, to further raise the casting lS temperature of the material which is cast secondly, which intensifies the thermal shocks and increases the risks of cracking of the inserts.
The purpose of the pre~ent invention is to provide a new method of manufacturing a bimetal casting having a high insertion rate, whose properties result not only from the individual properties of each component, but also from a useful synergic effect generated by the juxtaposition of the two components and due either to the morphology or to the dimensioning or to the choice of the materials of the components.
In order to achieve this objective, the present invention proposes a method of manufacturing a bimetal casting comprising ca~ting an insert in a first mould, in disposing the insert thus cast in a second mould, and in casting the part in this second mould around the insert, characterised in that the casting in the second mould is carried out in such a way as to avoid any metallurgical bond between the insert and the cast alloy, the bond being a mechanical bond due to an appropriate shape of the insert.
The invention also propose~ a bimetal wearing part produced according to this method and comprising at least one insert made of a material with a high resis-tance to wear and a cast support made from a more ductile ~a~ l.2~
~ Ds ~
ma~erial resis~ant ~.o mechanical stre~,ses, in which ~he mas~ of the insert~ repre~ants at least 30% of the ma s of th~ par~, characterised by a m~chanic~l ~ond between the insert or inserts and the support, th~ ~aid metallur-~ical bond being reinforced by an appropriate geometricshape of the insert.
In order of avoid the fonmation o~ a metallur ~ical bond hetween the insert;s and the ~upport and in order to reduce the effect ,of ~h~ ~1 shocks, it i8 pos~ible~ depending on the ma~;ivenes~ of tha insert~, to submit the latter to a prelimina~y preparation. This preparation can for ex2mple con iStl when the ma3sivene~s of the inserts is not too great, in a simpla heat treat-ment. When the ma~sivene~s increa~e~, it i~ possible to provide the in~erts with a refractory coating ~orming a ~r~l barrier. When the ma~siYane~ very great, it is even pos~ible to envisage pro~iding the insert~ with a ~eramic coating.
The mathod allow3, by a judiciou~ choice of the ~0 nature and morphology of the two component , the gener ation in ~ervice o~ a ~ear profile which will maintain or optLmi~e the work; n~ of the part.
~ he in~e~tio~ al~o provides, by way of advan-~ageou~ appli~ation, a c~u~hsr ferrule of cylindrical or truncated co~ 6hap~ with a c~tral bore ~or ~eceiving a support hub co~tituted by a -~h in~ble ductile casting on the ~urface of whioh are lo~git--A i n~ 1 ly ' ~e~e~, in the direction of the g~neratrix, wear insert~, each in~ert b~ing ~eparatsd fro~ the ~o ad~ac~t in~erts by a radial fin co~tituted by a la~er of the s~id ductile casting.
~ach in~ert can cOmpri~Q a ~ection of ~ubstan-tially parallelepipedic ~hape con~tituting a wearing part which i~ r~ lly prolonged towards the centre of the ferrule by a longitn~i n~l ~arrowi~g having a "dovetail~
,~h~fi cro~ ectio~ fc in~ the zone sf m~chAnicAl bond wl~h the ductile easting. The ~doY~ail" shaped cro~-section ca~al~o be replac~d by rh~nnell ~ cro s~eckion~.
The ~pacing be~ween ad~acent in~ert~ can be CA 020~1221 1998-01-29 determined by protruding radial ribs provided on the longitudinal sides of the mserts.
According to an advantageous embodiment, the ferrule includes a first base and a second base opposed and generally parallel to the first base. The inserts extend from the first base to a plane disposed generally parallel to and intermediate the bases such that a peripheral ring of ductile casting is defined by the plane and the second base.
The invention also provides a crusher hammer constituted from a part in the shape of a sector of circle whose inside point comprises an opening through which a suspension and pivoting shaft can be passed and which is produced according tothe method proposed above, characterised in that the point forms a support made from m~chin~hle ductile casting and in that the outer section is an insert having a high resistance to wear and in that the insert and the support are integral with each other by means of a mechanical bond.
This mechanical bond can be provided by a central prolongation of the insert or of the support, this prolongation being provided with lateral channels. This bond can furthermore be reinforced by a frontal groove on the support or on the insert.
The mechanical bond can also be provided by an interior sector of the insert having a reduced thickness and with a transverse opening, the said sector of reduced thickness being embedded in the support by the casting of the latter.
Other characteristics and features of the invention will emerge from the detailed description of several embodiments given below by way of illustration with reference to the appended drawings in which:
- Figure 1 is diagrammatic view of a vertical crusher;
- Figure 2 shows details of a crusher at the point of crushing;
- Figure 3 is a perspective view of a ferrule of a crushing wheel according to the present invention;
- Figure 4 is a perspective view of a first embodiment of an insert, according to the present invention, of a crushing ferrule;
~ FL~ures S and 6 respectively show a radial cross-section and an axial cross section of a variant of the ferrule shown in Figure 7;
- Figure 7 shows the peripheral wea.r of a ferrule.
- ~igure 8 shows a view, similar to that of Figure 4, of a second embod.Lnent of an insert of a crushing ferrule;
- Figure 9 is a side view of a cru~her hammer produced according to the present invention;
- Figure 10 is a central, vertical cross-section of the hi ?r sho~n in Figure 9;
- Figure 11 shows a ~econd e~bodLment of a crusher h - r; and - Figure 12 ~hows the central vertical cross-~ection of the hi -r showm in Figure 11.
A fir~t ad~antageou~ application of the use of composite wearing part~ manufacturPd in accordance with the present inventlon will now be described with refer-ence to a vertical crusher with wh~el~ ~uch as showndia~ ~tically in Fiyure 1 but which will also be valid for a pre~s with rollers. Such crushers are, for ex~mple, used for cru~hi n~ coal or clinker. ~hey are ~ssentially con3ti~uted by a rotary track 30 over which cru~hing wheal~ 32 moYe- ~he material to be crushed i~
inL~o~k~e~ through a cent~al feed ch~nne~ 34 and fall~
onto the track 30 wh~re it i~ s~l~h~ and c Ns~d between that track a~d the wheel~ 32. A~ ~hown in grsater d tail in Figure 2, the crushed material i3 taken up, at th~ periphery of the tra~k 30, by a upward curr3nt of hot air and at th~ ~ame time i~ separated under the affe~t of ~ravlty a~d of a ~ep~rator 36 aceording to the gr~n~ Lry. In order to avoid ~rictio~ between the wheel~ 32 and the traeX 30, the wheel~ 32 mu~t ha~e truncated co~e shape a~ ~hown in ~igure 1. It is al~o pos~ible ~o provide wheel~ 40, a~ in ~he ~mho~i 9~t shown in Figure 2, ha~ing a corlve~ rolling ~rfaceJ the track 38 havi~g a correspon~in~ concaYe ~nn~ r ~urface.
~he cru~hing wheel~ are gen~rally con~tituted by .
~3 r~ 21 an annular ferrule having a cylindrical or truncated cone shape, mount~d on a hub. They must, on the one hand, have a sufficient resistance to the wear cau~ed by the crushing and, at the same tLme, be able to be machined in order to be mounted on the hub. The known ferrules are generally cast in Ni-hard alloy or in ferrochromium and then machined with high precision, (inside diameter with an H6 tolerance in certain ca~ec~) before being mounted on tneir hubs.
In service, the wear of ~uch a ferrule progresses in a generally unifoxm ~nn~r at all poin~ along a circular line over a radial ~ection. On the other hand, ~he wear i~ generally variable along a ~ame generatrix, the ends, in par~icular the peripheral end~, wearing more ~lowly then the central ~ection. Furthermore, a pro-gre~3iva polishiny of the working surfac~ is caused resulting in an increased ri~k of ~lipping between the ferrule and the material to be crushed.
The result of thi3 i8 that the pro~ile of the working surface3 becomes modified and the system for taXing up play no lon~er allow~ the opti~um cru~hing condition to be restorad. Fur~h~ -~e/ a8 the outer ~urface heG' -~ poli~h~, the slipping be... e~ the matexial to be cru~hed a~d the ~urface of the f~rrule accelerates ~he wear and reduces th~ output rate, par-ticularly if the material to be crushed is wetO
In order to overcome these di~a~va~tage~, ~he pre~ent invention proposes, in its application to a crusher, to prod~ce the ferrules with inserts a~ ~ho~n in Figure 3. Su~h a ferrule i~ therefore con3tituted by a~
~nm7lAr ~uppor~ 42 made from duc ile and ~aGhin~hle ca~ting, in which are e~bedded peripheral in~ert~ 44 mad2 from a material haYing a high resistance ~o abra~ion, for example ferrochromium, and f~- i ng the working and wearing surf,ace of the ferrule.
~ rhe insert~ 44 are fir~tly ca~t separately in a~p~ iate mould~. These in~erts 44 ad~antageou~ly have the ~hape ~hown in perspective in Figure 4. They are co~tituted ~y an outer ~ction 46 ha~ing a ub~tan ia~ly ~ ~3 ~
p~rallelepipedic ~hape and a cro~s-~ection which i9 slightly that of a truncated cone along the radius of curvature of the ferrule. This section is prolonged ~oward~ the base, or the in~ide of the ferrule, b~y a longitudinal narrowed foot 48 having a radial cros8-section of "do~etail" shape ancl formins the zone of bond with the support 42. Each insert 44 comprise~, on at least one of its longit~ n~l sides of the section 46, in the embodiment shown, two protruding ribs 50.
10The ins2rts 44 ~re then placed in the mould for the casting of the ferrules in ~uch ~ way as to lins the entire periphery of the mould. The inserts 44 are ~uxtaposed in such a way that their rihs 50 are in mutual contact in order to def ine, between two juxtapo~ad 15insert~, a space 52 whose width dapends on the size of the ribs 50. The purpose of these ri~ 5Q i~ to cause, during the casting o~ the ~u~olL 42, a spreading o~ the ductile casting into the spaoe~ 52 in order to form, between all of the ad~acent in~erts 44, a fine radial fin 20of ductile ca~tin~.
According to one of the features of the prese~t i~vsntion the ca~ting of th~ fsrrule is carried out in such a way a~ to avoid any metallurgical bond betwe~n the ~upport 42 and the ill8ert8 44. For thi~ purpose thf3 25in~ert~ 44 can ~Inde~o a prel i in;~ry preparation, for ~rl e a he~t trea~ent in or~er to reduce cracking risk~. If the m~s~iveness of the in~ert 44 i~ relati~e-ly larg* with respe~t to the 3upport 42 it i8 among other things po~sible to coat the insert 44, before ca~ting the 30forrule, with a refractory coating intended to form a t.h~ ~1 karrier.
The ~emparatuxe o~ the ma~erial ~o~ming the ~u~pO~ 4~ mu3t there~ore no longer be a~ high, during the casting o~ the ferrule, a~ in the ca~e o~ a oa~tin~
35with the ~ormation of a metallurgical bond. ~hi~ ha~ the ad~antage o~ reducing the thermal ~hocks which the in~ert~ 44 unlergo durin~ thi5 ca3ting. The latter are con~equently le88 ~ro~e~ to the ri~X~ of cra~k forma-tion. If/ de~pite thi~ precautlon, a crack ~hould form ~-3:l2~
in ~he in~ert 44, this crack would not propagate beyond the insert given that the absence of metallurgical bond prevents its progression through the material of ~he support 42. In other word~, the method proposed by the invention reduces the risk of formation of crack~ in the inserts 44 and furthermore prevents their progression through the support.
The purpose of the fins 52 is to cau~e~ by the worXing of the wheel, a preferential wear of the ductile alloy and the formation of grooves be~ween the inserts 4 for th~ purpose of gripping the material to be crushed.
In ord~r to have optimum output it is therefore neces~ary to choose the spacinq between the inserts 44 as a func-tion of ths friction characteristi~s of the matQrial used, of it~ granulomet~y and of it~ angularity.
~he morphology and the shape of the inserts 44 i~
therefo.re dictated ~y ~everal criteria. ~heir wi~th and their spacing mu3t allow a circumferQntial pitch o~faring an optimum driving of ths material u~ed. The profile of the section 48 of each insert 44 all~w~ an excellent -ch~nical ~ond between the insert~ 44 and th~ ~upport 42 with a r; ni of concentration of tension in the ferrochromium of the in~art~. The radial height of ths insert~ 44 allows a large u~able thic~ne~ and a good -~h~nical bond up to the end of it~ service life.
Finally, ~he rib~ 50 allow easy ad~u3~ent and position-ing o$ th~ in~e~ 44 in the mould~
A ferrule producad with in~ert. ~uch as described above ha~ se~aral ad~a~tage~ with r~3pect to the k~own ferrule8. The ma~hi~;n~ and ~erruli~g opera~ion i~ le~8 ~ c~te and le88 expen~ive h~CA~I~e of the duotili$y of th. $upport 42. Thi~ ductility al~o re~nc~s ri8k3 Of ~udden fracture through tha c ~lete cro~-sQ~tion of ~he part a~ a result of ~tatic farruling 8tre8~e~ and of operational fatigue. It i po~ible to use cast iron3 with a high chro~e cont~nt~ tha~ i~ to ~ay wi~h very great hardn~s~ (grea~er ~han 65 Rc) the machining 0~
w~ich i~ ex~rem~ly difficult and ~n~ive. A~ the 8amQ
tlm2~ the mzmufacturing ~ethod allo~8 a b~tter rate of 2 ~ 2 2 1 - 1.0 ~
se Of the costly ferrochromium.
In addition to the advanta~3es 1isted above which in fact are intrinsic ad~antages due to the propertie~ of each of the materials present, the association of the~e materials senerates a synergic effect offering other advantag~s. Thus, for example, it is possible to achieve a compression of the inser-ts by the e~pansion of the ferrochromium during its ma:rtensitic transPormation dnring hardening, whil~ the ducl:ile ca~t:ing completas its 19 cooling with a linear shrinkage. This compression of the working surface has a positive effec~ on it~ resistance to fatigue and al~o, in certain ca~es, on its re~iqtance to abrasion. Furthermore, it is possib1e to generat~ a wearing ~urface retAin;n~ the initial profi1e with, in addition, hollows between ~he inserts which faYour the driving of the material. In brief, the ferrules produced according to the proposed method offer an increased r~ tance to wear, an increa~ed mech~nic~l re1iabi1ity and an increased production ra~e duriny ~heir ~erv ice life.
~ method o~ producing a ferru1e allow~g compen-sation of the wear profi1e a10ng the generatrix will now be described with referencQ to Figure~ 5 to 7. In fact, an irr~gular wear prof ile along the generatri~c i~ par-ticularly~ harmful in the ca~e of ~ertical c~her~ with wheel~ accordin5~ to Figure 1 in ~hich the material i3 displa~ed r~ 1 y on the traclc along the generatrix of the whe~21s and where t}le îormation of a pocket b~tween the whe01 and the track i responsible for harmful 3 a co~sequ~nces. In fact, the ~o~ ion rate can drop to 509~ of the ; n~l produc~ion rate obliglng a pre~aturs raplac~ or r~-m~chinin~ of ths wheel~ bPfore the entire u~aful l-h~ck~Q~ o~E kha wea~ g layer :i.8 ~orn out.
~urth~ -.e a metal-to-~tal contack i~ pro~l~ce~ be~wee~
the ~lightly worn end3 of the whee1 and of the track which cause~i a rapid deterioration of the~e wearing par~O The~e disad~antages a:ra everl ~ora prorlounced in the ca~e of f lat trac3cs an~ of wheels hav~in~ ~traight generatrice3 like tho~e ~ho~n in Figure lo In ~uch 5 1 ~
case th~re is an adva~age in using the pos~ibilities of ~the manufacturing method ac~ording to the presen~ inven-tion in order to take advan~age of the presence of ~wo mat~rial~ having different properties in order ~o accele-S rate the wear of ~he regions which wear less than others by consequently modifying the morphology of the inserts.
~ shown in Figures 5 and 6, the ~errule 60 comprises in~erts 62 ~hich do not extend over the entire length of the generatrix in such a way as ~o allow a peripheral nose 64a, which is part of the ductile casting support 64 to l. ~ in on the outi3r edge of the wheels . A
faster wear is therefore voluntarily provoked in thi5 region of the wheel in oxder to cnmren~ate for the fact that this region no_ ~lly wear~ more slowly. Fiquxe 7 shows the developm:3nt of the wear of ~uch a ferrule 60.
The profile identified by A repre~ent~ the outer circum~
ference of the ferrule 60 in the new unworn s~ate. Th~
line B represent~ the development of the wear profile when the ferrule has a uni~o.rm hardne5s over the entixe lenqth of its generatrix, while the ~l~sh~. line C
represents the development of the wear profile such as correcta~l by a ferrule according to Figure 6 with a mora ductile outer edg~ 64a.
A~ mant i on~l above, the special ~hape of the in~erts 4L4, particularly their dovetail ~hape 48 contrib-utes to consolidati~ th~ -oh~ni~l bond be~w~en the in~erts 44 and the HU~eL ~ 42 . Whan the in~erts are r~latively mas~ive, it i~ po~-cible, in order to increase - the contact 5urface while avoiding having to make cut~
which ar~ too deeR i~ order to ~onm the dovetail ~hape~, to provide in~ert~ ~uch a~ 9how~ in Figure 8. Such an in~ert 64 i~ compaxable with ~he i~ert~ 44 of Pigure 4 e~cept that the in8ida 8ectlon 66 compri~e~, o~ its two lonyitu~;n~l sides, corruga~ion~ or Ch~ 18 68 ~c_ in~
kind of ~ltiple dovetail. The -ch~ni~ ond zone i~
there~ore ~e]parate and i~ e~~ect ~ heh i n~ the ~ear zone t which avoLd~ a certain ~ ~r of di~advantaga~ nt ~he end of the 8er~ice li~e with re8pect to ~he sLmpla dovetail bec- ~ n~ level with the working 9urface.
~3~.2~
- 12 ~
Ficlure~ 9 and LO show another applica~ion usLng a composite casting produced in accordance with the present invention. In this instance it is a crusher hammer. Such crushers yenerally comprise a rotary drum on the ~urf ace of which crusher h- ~rs are attached in a pivoting manner on longitudinal shafts. Th~ hammer 70 shown in Figure 9 has a shape which is approxi~at~ly a sector of circle with a bore 7'2 for mounting on a shaft in a c~usher with h; -rs. This h~- :r is a bLmetal casting produced according to the pre~ent invention and comprises an insert 74 made from a material with a high re istance to wear and a support 7 6 made :Erom a more ductile ma~erial re~istant to ~tresse~. The in~ert 74 is firstly cast in a f ir t mould and the support 7 6 is then cast o~er the insert 74 in another mould. The bond between the support 76 and the insert 74 i~ an exclusively mechanical bond. In order to consolidate thi~ bond, it i~ preferable to pro~uce an in~ert 74 having, on the side of its bond with the support 76, a prolongation 78 provided with lateral channel3 80. The ' ~r o~ these ~h;-nnPl 8 depend~ on the de~ires~ solidity to be obt~in~ for these bond~. It i8 po~sible, for exalnple, to providQ ju~t a ~ingle ch;-nnel in order to produce a dovetail ~haped bond. In~tead of providing the ch~nn~ 80 on a prolongation of the insert 74 it is also pos~ible to provide them in a cut-out in the in~ert 74 in order that the ~upport extend~ in~ide the latter.
In Qrdsr to i " ova tha f ixing in the tran~versQ
disectio~, that i~ to 8~1y pe~n~ ular to the plane of Figure 9, it i~ po~ible to provide, on the front ~ide o~
the in~ert 74, on the . ide of the ~upport 76, a protrud ing rib 82 or a qroove. Tha xeference 82 ~e figure 10) show~ nuch a coll~olidating rib.
Figure~ 11 a~d 12 show another: '~A; -- t o~ a crusher h~er 84 produced according to the pre~eIlt inv ntion. The h~ - 84 al~o compri en an insert 88 ha~ring a hiç~h re~i~tanc~ to wear, over which i~ cast a duckile ~upport $~. The in~ert 88 comprises, on the si.de of the ~llpt~OL L B6, a aector 90 o~ thicknea~ reduc:ed .
2 ~ ~
(3ee Figure 12) for example to the central thi~d of ~he thickness of the re5t of th~ in~ert 88. This secto~ 90 furthermore comprises a transverse opening 92. During the casting of the support 86, l:he casting take~ place on either ~ide of the sector 90 of reduced thickne~s and th~ough the opening ~ in srder to fonn the configuration shown in cross-section in figure 12. The ~uppor~ 86 and the insert 88 are therefors perfectly integrated in ~ach other with an e~trem~ly stable mechanical bond in both the tran~ve~se and longitudinal direction~. Thi~ embodi-ment fur~-h~ -re has th~ advantage that the ~ear of the inRert 88 follow~ the ~hape of the ductile ~U~OL ~ 86.
Finally, it must be empha~ised that the two applica~ions described ab~ve, namely the ferrule and the crush0r hammer, have bean pre~ented only by way of illu -tration. Othsr application~ exi~t whi~h are capable o~
benefiting from the ad~antage~ o:Efered by the pre en~
invention, particularly applications with compo~ite wearing part~ ha~ing a high insertion rate, for example :eerrule~ which can be used on cyl i n~r-type de-a~glomera -tor~ used at the output of cooling unit~ in order ~o break up the scale arld in w~ich the insertion rate can be in the oxder of 8096.
M~thod of manufacturinq a bimetal castinq and wea~inq part Produced by thi~ method The pre~ent invention relates to a method of manufacturing a bLmetal casting and a wearing part produced by this method, particularly ferrules and crusher hammers.
Many wearing parts, for example in the field of c~ushers, are ~ub~ected to high m2chanical ~tresses in the mass and to high wear by abrasion on their working ~urface, ~uch that it i~ desirable that these part~
should have a high resistance to abra~ion and a certain ductility to be able ~o re~ist mechanical ~hock stre~e~, and po~sibly to be able to be machined. Now, it i~ well known that these propertie~ are not compatible. I~ i~ of 15 course pos3ible to choose a steel exhibiting a c~~,- ;~e between these two oppo ite properties, but this mUct necessarily be done to the detriment of re~i~tance to wear or of ductility.
In order to avoid ~uch compromi~es, it i~ known to produce composite part in which the ~ection expo~ed to abrasion i8 con~tituted ~y ferrochrom$um with a high re~istance to abrasion ~upported by a core made from a more ductile steel. Thi~ allows the w~ar of the part to ~e reduced while allowing the core to be machined and avoidin~ its bre~k~ge during this operation. Purther-more, it i~ posslble to reduce its manufacturing cost b~
a ~udiciou~ choice of it~ c ~-~nts.
Several man~~acturing method~ of such c~~ , 6ite or bLmet21 parts are known. ~hu~, for example, the ~ 30 Patent ~V-64303 propo~es a manufacturing method for : c J3ite par~3 by ~uccessive ca~ting~ of material~
~ having di~ferent or comple~entary properties. ~his : techniqu~ however has two re~triction~. Firstly, tha : method necessarily implies the exi~tence of a horizontal separating ~urface between the two cast metal Further-more, tha casting mu~t be relatively massive to allow the ~ucces~ive ca ting of th~ two metal~ while obt~ining 2 correct metallurgical bond be~ween ~hese m~tal~. The~e two restri.ction~ lLmit the field of applica~ion of the , ~.. . , , ., ., . . :
.. . '' ' ~ ' . ' ',' '' ' ' ' ~ - .. . . ..
.. . . . . ,. .. . - .. . . .
.. . .. . . . .
. -- . . , - . , .
, .: . . . , . -, , . ~ '' ,, ~ 2 - ~0~22~
~olution proposed by the abovem~ntioned pat~nt.
It i~ also known to produce bimetal wearing part3 by welded assembly. A1though, in theory, a welded assembly does not have 1Lmits at the level of -the mor phology of the components to be assen~led~ in practice such li~its exist and they depend on th~ welding m~thod used. Furthermore, all welding method~ applied to fragile materials require a perfect control o~ their h~ating and cooling cycle, and a very accurat~ position-in~ of the surfaces to be as~e!mbled. The result of this i~ that a welded assemb1y is a relatively expen~ive ~echnique and is of limited applica~ion.
It is also known t~ produce bimetal partq by brazed assembly. Thiq technique offers the possibility of assembling components Of ~ariou~ hapes, but it ~till reguire~ a very accurate machin;ng of the contact ~ur-face~ and positioning devices which are alqo very accu rate.
High tempera~ure brazing offers mechanical p.o~e~Lie~ comparab~e with welding, but it requireq meticulous oper~ting precaution~ and the use of special furnaces, particularly vacuum furnace~, if its i~ deqired to obtain a rellable assembly. ~hiR results in a rela~
ti~ely high manufacturing co~t.
With regard to low temperature brazing, ~ust lik~
glueingJ it is certainly le~s ~xpensilTe but the mechan ical characteris~ics of the assembly are distinctly inferior and e~en insuf~icie~t for highly ~tre sed ; wearing part~.
The e variou~ t~chniqu~ are in par~icular le-- -n~d by the do~ EP-A~-0,271,336 for th~
manufacture of crusher ferrule~. ~he surface of Yuch a ferrule i~ expo ed to hi~h tension3 which generate crack~
propaga~ing ~hrough ~he ~uQpo~l~ O~ the ferrllle in order to render the latter rapidly usele~s.
The Pal;ent US-4, Og9, 988 propc)ses the u-~e of th~
technique of insert3 for the production o bimetal armour plates, for. }~la~t fur~ace~. According to this patent, in erts are f ir~tly ca~t in ~ir~t ~ould~, these i~sert~
.
. ~ . .. ~ .
CA 020~1221 1998-01-29 are then pl~ced in a second mould into which the part is cast around the inserts in order to form a metallurgical bond between the inserts and the support material. This method has the disadvantage that the inserts undergo thermal shocks during the casting of the parts. The thermal shocks generate internal tensions and cracks which propagate not only through the inserts but, because of the metallurgical bond, also through the support.
This disadvantage appears to a greater degree when the insertion rate is high, that is to say when the mass of the inserts is relatively large with respect to the mass of the support as in this case it is necessary, in order to ensure the formation of the metallurgical bond during the casting of the part, to further raise the casting lS temperature of the material which is cast secondly, which intensifies the thermal shocks and increases the risks of cracking of the inserts.
The purpose of the pre~ent invention is to provide a new method of manufacturing a bimetal casting having a high insertion rate, whose properties result not only from the individual properties of each component, but also from a useful synergic effect generated by the juxtaposition of the two components and due either to the morphology or to the dimensioning or to the choice of the materials of the components.
In order to achieve this objective, the present invention proposes a method of manufacturing a bimetal casting comprising ca~ting an insert in a first mould, in disposing the insert thus cast in a second mould, and in casting the part in this second mould around the insert, characterised in that the casting in the second mould is carried out in such a way as to avoid any metallurgical bond between the insert and the cast alloy, the bond being a mechanical bond due to an appropriate shape of the insert.
The invention also propose~ a bimetal wearing part produced according to this method and comprising at least one insert made of a material with a high resis-tance to wear and a cast support made from a more ductile ~a~ l.2~
~ Ds ~
ma~erial resis~ant ~.o mechanical stre~,ses, in which ~he mas~ of the insert~ repre~ants at least 30% of the ma s of th~ par~, characterised by a m~chanic~l ~ond between the insert or inserts and the support, th~ ~aid metallur-~ical bond being reinforced by an appropriate geometricshape of the insert.
In order of avoid the fonmation o~ a metallur ~ical bond hetween the insert;s and the ~upport and in order to reduce the effect ,of ~h~ ~1 shocks, it i8 pos~ible~ depending on the ma~;ivenes~ of tha insert~, to submit the latter to a prelimina~y preparation. This preparation can for ex2mple con iStl when the ma3sivene~s of the inserts is not too great, in a simpla heat treat-ment. When the ma~sivene~s increa~e~, it i~ possible to provide the in~erts with a refractory coating ~orming a ~r~l barrier. When the ma~siYane~ very great, it is even pos~ible to envisage pro~iding the insert~ with a ~eramic coating.
The mathod allow3, by a judiciou~ choice of the ~0 nature and morphology of the two component , the gener ation in ~ervice o~ a ~ear profile which will maintain or optLmi~e the work; n~ of the part.
~ he in~e~tio~ al~o provides, by way of advan-~ageou~ appli~ation, a c~u~hsr ferrule of cylindrical or truncated co~ 6hap~ with a c~tral bore ~or ~eceiving a support hub co~tituted by a -~h in~ble ductile casting on the ~urface of whioh are lo~git--A i n~ 1 ly ' ~e~e~, in the direction of the g~neratrix, wear insert~, each in~ert b~ing ~eparatsd fro~ the ~o ad~ac~t in~erts by a radial fin co~tituted by a la~er of the s~id ductile casting.
~ach in~ert can cOmpri~Q a ~ection of ~ubstan-tially parallelepipedic ~hape con~tituting a wearing part which i~ r~ lly prolonged towards the centre of the ferrule by a longitn~i n~l ~arrowi~g having a "dovetail~
,~h~fi cro~ ectio~ fc in~ the zone sf m~chAnicAl bond wl~h the ductile easting. The ~doY~ail" shaped cro~-section ca~al~o be replac~d by rh~nnell ~ cro s~eckion~.
The ~pacing be~ween ad~acent in~ert~ can be CA 020~1221 1998-01-29 determined by protruding radial ribs provided on the longitudinal sides of the mserts.
According to an advantageous embodiment, the ferrule includes a first base and a second base opposed and generally parallel to the first base. The inserts extend from the first base to a plane disposed generally parallel to and intermediate the bases such that a peripheral ring of ductile casting is defined by the plane and the second base.
The invention also provides a crusher hammer constituted from a part in the shape of a sector of circle whose inside point comprises an opening through which a suspension and pivoting shaft can be passed and which is produced according tothe method proposed above, characterised in that the point forms a support made from m~chin~hle ductile casting and in that the outer section is an insert having a high resistance to wear and in that the insert and the support are integral with each other by means of a mechanical bond.
This mechanical bond can be provided by a central prolongation of the insert or of the support, this prolongation being provided with lateral channels. This bond can furthermore be reinforced by a frontal groove on the support or on the insert.
The mechanical bond can also be provided by an interior sector of the insert having a reduced thickness and with a transverse opening, the said sector of reduced thickness being embedded in the support by the casting of the latter.
Other characteristics and features of the invention will emerge from the detailed description of several embodiments given below by way of illustration with reference to the appended drawings in which:
- Figure 1 is diagrammatic view of a vertical crusher;
- Figure 2 shows details of a crusher at the point of crushing;
- Figure 3 is a perspective view of a ferrule of a crushing wheel according to the present invention;
- Figure 4 is a perspective view of a first embodiment of an insert, according to the present invention, of a crushing ferrule;
~ FL~ures S and 6 respectively show a radial cross-section and an axial cross section of a variant of the ferrule shown in Figure 7;
- Figure 7 shows the peripheral wea.r of a ferrule.
- ~igure 8 shows a view, similar to that of Figure 4, of a second embod.Lnent of an insert of a crushing ferrule;
- Figure 9 is a side view of a cru~her hammer produced according to the present invention;
- Figure 10 is a central, vertical cross-section of the hi ?r sho~n in Figure 9;
- Figure 11 shows a ~econd e~bodLment of a crusher h - r; and - Figure 12 ~hows the central vertical cross-~ection of the hi -r showm in Figure 11.
A fir~t ad~antageou~ application of the use of composite wearing part~ manufacturPd in accordance with the present inventlon will now be described with refer-ence to a vertical crusher with wh~el~ ~uch as showndia~ ~tically in Fiyure 1 but which will also be valid for a pre~s with rollers. Such crushers are, for ex~mple, used for cru~hi n~ coal or clinker. ~hey are ~ssentially con3ti~uted by a rotary track 30 over which cru~hing wheal~ 32 moYe- ~he material to be crushed i~
inL~o~k~e~ through a cent~al feed ch~nne~ 34 and fall~
onto the track 30 wh~re it i~ s~l~h~ and c Ns~d between that track a~d the wheel~ 32. A~ ~hown in grsater d tail in Figure 2, the crushed material i3 taken up, at th~ periphery of the tra~k 30, by a upward curr3nt of hot air and at th~ ~ame time i~ separated under the affe~t of ~ravlty a~d of a ~ep~rator 36 aceording to the gr~n~ Lry. In order to avoid ~rictio~ between the wheel~ 32 and the traeX 30, the wheel~ 32 mu~t ha~e truncated co~e shape a~ ~hown in ~igure 1. It is al~o pos~ible ~o provide wheel~ 40, a~ in ~he ~mho~i 9~t shown in Figure 2, ha~ing a corlve~ rolling ~rfaceJ the track 38 havi~g a correspon~in~ concaYe ~nn~ r ~urface.
~he cru~hing wheel~ are gen~rally con~tituted by .
~3 r~ 21 an annular ferrule having a cylindrical or truncated cone shape, mount~d on a hub. They must, on the one hand, have a sufficient resistance to the wear cau~ed by the crushing and, at the same tLme, be able to be machined in order to be mounted on the hub. The known ferrules are generally cast in Ni-hard alloy or in ferrochromium and then machined with high precision, (inside diameter with an H6 tolerance in certain ca~ec~) before being mounted on tneir hubs.
In service, the wear of ~uch a ferrule progresses in a generally unifoxm ~nn~r at all poin~ along a circular line over a radial ~ection. On the other hand, ~he wear i~ generally variable along a ~ame generatrix, the ends, in par~icular the peripheral end~, wearing more ~lowly then the central ~ection. Furthermore, a pro-gre~3iva polishiny of the working surfac~ is caused resulting in an increased ri~k of ~lipping between the ferrule and the material to be crushed.
The result of thi3 i8 that the pro~ile of the working surface3 becomes modified and the system for taXing up play no lon~er allow~ the opti~um cru~hing condition to be restorad. Fur~h~ -~e/ a8 the outer ~urface heG' -~ poli~h~, the slipping be... e~ the matexial to be cru~hed a~d the ~urface of the f~rrule accelerates ~he wear and reduces th~ output rate, par-ticularly if the material to be crushed is wetO
In order to overcome these di~a~va~tage~, ~he pre~ent invention proposes, in its application to a crusher, to prod~ce the ferrules with inserts a~ ~ho~n in Figure 3. Su~h a ferrule i~ therefore con3tituted by a~
~nm7lAr ~uppor~ 42 made from duc ile and ~aGhin~hle ca~ting, in which are e~bedded peripheral in~ert~ 44 mad2 from a material haYing a high resistance ~o abra~ion, for example ferrochromium, and f~- i ng the working and wearing surf,ace of the ferrule.
~ rhe insert~ 44 are fir~tly ca~t separately in a~p~ iate mould~. These in~erts 44 ad~antageou~ly have the ~hape ~hown in perspective in Figure 4. They are co~tituted ~y an outer ~ction 46 ha~ing a ub~tan ia~ly ~ ~3 ~
p~rallelepipedic ~hape and a cro~s-~ection which i9 slightly that of a truncated cone along the radius of curvature of the ferrule. This section is prolonged ~oward~ the base, or the in~ide of the ferrule, b~y a longitudinal narrowed foot 48 having a radial cros8-section of "do~etail" shape ancl formins the zone of bond with the support 42. Each insert 44 comprise~, on at least one of its longit~ n~l sides of the section 46, in the embodiment shown, two protruding ribs 50.
10The ins2rts 44 ~re then placed in the mould for the casting of the ferrules in ~uch ~ way as to lins the entire periphery of the mould. The inserts 44 are ~uxtaposed in such a way that their rihs 50 are in mutual contact in order to def ine, between two juxtapo~ad 15insert~, a space 52 whose width dapends on the size of the ribs 50. The purpose of these ri~ 5Q i~ to cause, during the casting o~ the ~u~olL 42, a spreading o~ the ductile casting into the spaoe~ 52 in order to form, between all of the ad~acent in~erts 44, a fine radial fin 20of ductile ca~tin~.
According to one of the features of the prese~t i~vsntion the ca~ting of th~ fsrrule is carried out in such a way a~ to avoid any metallurgical bond betwe~n the ~upport 42 and the ill8ert8 44. For thi~ purpose thf3 25in~ert~ 44 can ~Inde~o a prel i in;~ry preparation, for ~rl e a he~t trea~ent in or~er to reduce cracking risk~. If the m~s~iveness of the in~ert 44 i~ relati~e-ly larg* with respe~t to the 3upport 42 it i8 among other things po~sible to coat the insert 44, before ca~ting the 30forrule, with a refractory coating intended to form a t.h~ ~1 karrier.
The ~emparatuxe o~ the ma~erial ~o~ming the ~u~pO~ 4~ mu3t there~ore no longer be a~ high, during the casting o~ the ferrule, a~ in the ca~e o~ a oa~tin~
35with the ~ormation of a metallurgical bond. ~hi~ ha~ the ad~antage o~ reducing the thermal ~hocks which the in~ert~ 44 unlergo durin~ thi5 ca3ting. The latter are con~equently le88 ~ro~e~ to the ri~X~ of cra~k forma-tion. If/ de~pite thi~ precautlon, a crack ~hould form ~-3:l2~
in ~he in~ert 44, this crack would not propagate beyond the insert given that the absence of metallurgical bond prevents its progression through the material of ~he support 42. In other word~, the method proposed by the invention reduces the risk of formation of crack~ in the inserts 44 and furthermore prevents their progression through the support.
The purpose of the fins 52 is to cau~e~ by the worXing of the wheel, a preferential wear of the ductile alloy and the formation of grooves be~ween the inserts 4 for th~ purpose of gripping the material to be crushed.
In ord~r to have optimum output it is therefore neces~ary to choose the spacinq between the inserts 44 as a func-tion of ths friction characteristi~s of the matQrial used, of it~ granulomet~y and of it~ angularity.
~he morphology and the shape of the inserts 44 i~
therefo.re dictated ~y ~everal criteria. ~heir wi~th and their spacing mu3t allow a circumferQntial pitch o~faring an optimum driving of ths material u~ed. The profile of the section 48 of each insert 44 all~w~ an excellent -ch~nical ~ond between the insert~ 44 and th~ ~upport 42 with a r; ni of concentration of tension in the ferrochromium of the in~art~. The radial height of ths insert~ 44 allows a large u~able thic~ne~ and a good -~h~nical bond up to the end of it~ service life.
Finally, ~he rib~ 50 allow easy ad~u3~ent and position-ing o$ th~ in~e~ 44 in the mould~
A ferrule producad with in~ert. ~uch as described above ha~ se~aral ad~a~tage~ with r~3pect to the k~own ferrule8. The ma~hi~;n~ and ~erruli~g opera~ion i~ le~8 ~ c~te and le88 expen~ive h~CA~I~e of the duotili$y of th. $upport 42. Thi~ ductility al~o re~nc~s ri8k3 Of ~udden fracture through tha c ~lete cro~-sQ~tion of ~he part a~ a result of ~tatic farruling 8tre8~e~ and of operational fatigue. It i po~ible to use cast iron3 with a high chro~e cont~nt~ tha~ i~ to ~ay wi~h very great hardn~s~ (grea~er ~han 65 Rc) the machining 0~
w~ich i~ ex~rem~ly difficult and ~n~ive. A~ the 8amQ
tlm2~ the mzmufacturing ~ethod allo~8 a b~tter rate of 2 ~ 2 2 1 - 1.0 ~
se Of the costly ferrochromium.
In addition to the advanta~3es 1isted above which in fact are intrinsic ad~antages due to the propertie~ of each of the materials present, the association of the~e materials senerates a synergic effect offering other advantag~s. Thus, for example, it is possible to achieve a compression of the inser-ts by the e~pansion of the ferrochromium during its ma:rtensitic transPormation dnring hardening, whil~ the ducl:ile ca~t:ing completas its 19 cooling with a linear shrinkage. This compression of the working surface has a positive effec~ on it~ resistance to fatigue and al~o, in certain ca~es, on its re~iqtance to abrasion. Furthermore, it is possib1e to generat~ a wearing ~urface retAin;n~ the initial profi1e with, in addition, hollows between ~he inserts which faYour the driving of the material. In brief, the ferrules produced according to the proposed method offer an increased r~ tance to wear, an increa~ed mech~nic~l re1iabi1ity and an increased production ra~e duriny ~heir ~erv ice life.
~ method o~ producing a ferru1e allow~g compen-sation of the wear profi1e a10ng the generatrix will now be described with referencQ to Figure~ 5 to 7. In fact, an irr~gular wear prof ile along the generatri~c i~ par-ticularly~ harmful in the ca~e of ~ertical c~her~ with wheel~ accordin5~ to Figure 1 in ~hich the material i3 displa~ed r~ 1 y on the traclc along the generatrix of the whe~21s and where t}le îormation of a pocket b~tween the whe01 and the track i responsible for harmful 3 a co~sequ~nces. In fact, the ~o~ ion rate can drop to 509~ of the ; n~l produc~ion rate obliglng a pre~aturs raplac~ or r~-m~chinin~ of ths wheel~ bPfore the entire u~aful l-h~ck~Q~ o~E kha wea~ g layer :i.8 ~orn out.
~urth~ -.e a metal-to-~tal contack i~ pro~l~ce~ be~wee~
the ~lightly worn end3 of the whee1 and of the track which cause~i a rapid deterioration of the~e wearing par~O The~e disad~antages a:ra everl ~ora prorlounced in the ca~e of f lat trac3cs an~ of wheels hav~in~ ~traight generatrice3 like tho~e ~ho~n in Figure lo In ~uch 5 1 ~
case th~re is an adva~age in using the pos~ibilities of ~the manufacturing method ac~ording to the presen~ inven-tion in order to take advan~age of the presence of ~wo mat~rial~ having different properties in order ~o accele-S rate the wear of ~he regions which wear less than others by consequently modifying the morphology of the inserts.
~ shown in Figures 5 and 6, the ~errule 60 comprises in~erts 62 ~hich do not extend over the entire length of the generatrix in such a way as ~o allow a peripheral nose 64a, which is part of the ductile casting support 64 to l. ~ in on the outi3r edge of the wheels . A
faster wear is therefore voluntarily provoked in thi5 region of the wheel in oxder to cnmren~ate for the fact that this region no_ ~lly wear~ more slowly. Fiquxe 7 shows the developm:3nt of the wear of ~uch a ferrule 60.
The profile identified by A repre~ent~ the outer circum~
ference of the ferrule 60 in the new unworn s~ate. Th~
line B represent~ the development of the wear profile when the ferrule has a uni~o.rm hardne5s over the entixe lenqth of its generatrix, while the ~l~sh~. line C
represents the development of the wear profile such as correcta~l by a ferrule according to Figure 6 with a mora ductile outer edg~ 64a.
A~ mant i on~l above, the special ~hape of the in~erts 4L4, particularly their dovetail ~hape 48 contrib-utes to consolidati~ th~ -oh~ni~l bond be~w~en the in~erts 44 and the HU~eL ~ 42 . Whan the in~erts are r~latively mas~ive, it i~ po~-cible, in order to increase - the contact 5urface while avoiding having to make cut~
which ar~ too deeR i~ order to ~onm the dovetail ~hape~, to provide in~ert~ ~uch a~ 9how~ in Figure 8. Such an in~ert 64 i~ compaxable with ~he i~ert~ 44 of Pigure 4 e~cept that the in8ida 8ectlon 66 compri~e~, o~ its two lonyitu~;n~l sides, corruga~ion~ or Ch~ 18 68 ~c_ in~
kind of ~ltiple dovetail. The -ch~ni~ ond zone i~
there~ore ~e]parate and i~ e~~ect ~ heh i n~ the ~ear zone t which avoLd~ a certain ~ ~r of di~advantaga~ nt ~he end of the 8er~ice li~e with re8pect to ~he sLmpla dovetail bec- ~ n~ level with the working 9urface.
~3~.2~
- 12 ~
Ficlure~ 9 and LO show another applica~ion usLng a composite casting produced in accordance with the present invention. In this instance it is a crusher hammer. Such crushers yenerally comprise a rotary drum on the ~urf ace of which crusher h- ~rs are attached in a pivoting manner on longitudinal shafts. Th~ hammer 70 shown in Figure 9 has a shape which is approxi~at~ly a sector of circle with a bore 7'2 for mounting on a shaft in a c~usher with h; -rs. This h~- :r is a bLmetal casting produced according to the pre~ent invention and comprises an insert 74 made from a material with a high re istance to wear and a support 7 6 made :Erom a more ductile ma~erial re~istant to ~tresse~. The in~ert 74 is firstly cast in a f ir t mould and the support 7 6 is then cast o~er the insert 74 in another mould. The bond between the support 76 and the insert 74 i~ an exclusively mechanical bond. In order to consolidate thi~ bond, it i~ preferable to pro~uce an in~ert 74 having, on the side of its bond with the support 76, a prolongation 78 provided with lateral channel3 80. The ' ~r o~ these ~h;-nnPl 8 depend~ on the de~ires~ solidity to be obt~in~ for these bond~. It i8 po~sible, for exalnple, to providQ ju~t a ~ingle ch;-nnel in order to produce a dovetail ~haped bond. In~tead of providing the ch~nn~ 80 on a prolongation of the insert 74 it is also pos~ible to provide them in a cut-out in the in~ert 74 in order that the ~upport extend~ in~ide the latter.
In Qrdsr to i " ova tha f ixing in the tran~versQ
disectio~, that i~ to 8~1y pe~n~ ular to the plane of Figure 9, it i~ po~ible to provide, on the front ~ide o~
the in~ert 74, on the . ide of the ~upport 76, a protrud ing rib 82 or a qroove. Tha xeference 82 ~e figure 10) show~ nuch a coll~olidating rib.
Figure~ 11 a~d 12 show another: '~A; -- t o~ a crusher h~er 84 produced according to the pre~eIlt inv ntion. The h~ - 84 al~o compri en an insert 88 ha~ring a hiç~h re~i~tanc~ to wear, over which i~ cast a duckile ~upport $~. The in~ert 88 comprises, on the si.de of the ~llpt~OL L B6, a aector 90 o~ thicknea~ reduc:ed .
2 ~ ~
(3ee Figure 12) for example to the central thi~d of ~he thickness of the re5t of th~ in~ert 88. This secto~ 90 furthermore comprises a transverse opening 92. During the casting of the support 86, l:he casting take~ place on either ~ide of the sector 90 of reduced thickne~s and th~ough the opening ~ in srder to fonn the configuration shown in cross-section in figure 12. The ~uppor~ 86 and the insert 88 are therefors perfectly integrated in ~ach other with an e~trem~ly stable mechanical bond in both the tran~ve~se and longitudinal direction~. Thi~ embodi-ment fur~-h~ -re has th~ advantage that the ~ear of the inRert 88 follow~ the ~hape of the ductile ~U~OL ~ 86.
Finally, it must be empha~ised that the two applica~ions described ab~ve, namely the ferrule and the crush0r hammer, have bean pre~ented only by way of illu -tration. Othsr application~ exi~t whi~h are capable o~
benefiting from the ad~antage~ o:Efered by the pre en~
invention, particularly applications with compo~ite wearing part~ ha~ing a high insertion rate, for example :eerrule~ which can be used on cyl i n~r-type de-a~glomera -tor~ used at the output of cooling unit~ in order ~o break up the scale arld in w~ich the insertion rate can be in the oxder of 8096.
Claims (9)
1. Method of manufacturing a bimetal casting comprising casting inserts of a material with a high resistance to wear in a first mould;
disposing the inserts thus cast in a second mould; and casting a more ductile material resistant to mechanical stresses around the inserts in the second mould;
wherein the inserts have two longitudinal sides, at least one side being provided with at least one protruding rib or similar means for determining a spacing between adjacent inserts disposed side by side;
the inserts are disposed side by side at a periphery of the second mould so that adjacent inserts are separated by said spacing;
the more ductile material is cast in the second mould to fill a remaining space thereof including said spacing between adjacent inserts such that a mechanical bond rather than a metallurgical bond is formed between the inserts and the moreductile material, which mechanical bond is reinforced by an appropriate shape of the inserts.
disposing the inserts thus cast in a second mould; and casting a more ductile material resistant to mechanical stresses around the inserts in the second mould;
wherein the inserts have two longitudinal sides, at least one side being provided with at least one protruding rib or similar means for determining a spacing between adjacent inserts disposed side by side;
the inserts are disposed side by side at a periphery of the second mould so that adjacent inserts are separated by said spacing;
the more ductile material is cast in the second mould to fill a remaining space thereof including said spacing between adjacent inserts such that a mechanical bond rather than a metallurgical bond is formed between the inserts and the moreductile material, which mechanical bond is reinforced by an appropriate shape of the inserts.
2. Method in accordance with claim 1 wherein the inserts are submitted toheat treatment prior to being placed in the second mould in order to reduce the risk of cracking during the casting of the more ductile material.
3. Method in accordance with any one of claims 1 or 2 wherein the inserts are provided with a refractory coating providing a thermal barrier.
4. Crusher ferrule of cylindrical or truncated cone shape with a central bore for receiving a support hub, the ferrule being produced by a method in accordance with any one of claims 1 to 3 and comprising a cast support made from machinable ductile casting on the surface of which are embedded longitudinally in the direction of a generatrix, wear inserts made of a materialwith high resistance to wear, each insert having two longitudinal sides, at least one side comprising at least one protruding radial rib or similar means determining a spacing between adjacent inserts, each insert being separated from a next adjacent insert by a radial fin constituted by a thin layer of said ductilecasting, wherein the mass of the inserts represents at least 30% of the mass of the crusher ferrule and a mechanical bond is formed between each insert and the support, said mechanical bond being reinforced by an appropriate geometric shape of each insert.
5. Crusher ferrule according to claim 4 wherein each insert comprises a section having a substantially parallelepipedic shape constituting a wearing part, said section further being radially prolonged towards a centre of the ferrule by a longitudinal narrowing, the narrowing having a dovetail-shaped cross-section forming a bond zone with the ductile casting of the support.
6. Crusher ferrule according to claim 4 wherein each insert comprises a section having a substantially parallelepipedic shape constituting a wearing part, the section being radially prolonged towards a centre of the ferrule by an inside section comprising, on each side thereof, longitudinal channels forming a mechanical bond with the ductile casting of the support.
7. Crusher ferrule according to any one of claims 5 or 6, wherein each insert comprises on at least one of two longitudinal sides thereof protruding radial ribs determining spacings between next adjacent inserts and the thickness of said radial fin.
8. Crusher ferrule according to any one of claims 4 to 7 having a first base and a second base opposed and generally parallel to the first base, whereinthe inserts extend from the first base to a plane disposed generally parallel to and intermediate the bases such that a peripheral ring of ductile casting is defined by the plane and the second base.
9. Crusher ferrule according to any one of claims 4 to 8 wherein the inserts are of chrome iron having a hardness equal to or greater than 65 Rc.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| BE9000895A BE1004573A4 (en) | 1990-09-20 | 1990-09-20 | Process for producing a piece bimetallic foundry and wear piece made thereby. |
| BE09000895 | 1990-09-20 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2051221A1 CA2051221A1 (en) | 1992-03-21 |
| CA2051221C true CA2051221C (en) | 1999-03-30 |
Family
ID=3884932
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002051221A Expired - Fee Related CA2051221C (en) | 1990-09-20 | 1991-09-12 | Method of manufacturing a bimetal casting and wearing part produced by this method |
Country Status (10)
| Country | Link |
|---|---|
| EP (1) | EP0476496B1 (en) |
| JP (1) | JP2799250B2 (en) |
| KR (1) | KR0149031B1 (en) |
| AT (1) | ATE119092T1 (en) |
| BE (1) | BE1004573A4 (en) |
| CA (1) | CA2051221C (en) |
| DE (1) | DE69107746T2 (en) |
| DK (1) | DK0476496T3 (en) |
| ES (1) | ES2069156T3 (en) |
| PT (1) | PT99013B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103056343A (en) * | 2012-12-21 | 2013-04-24 | 佳木斯大学 | Trimetal composite cast crusher hammer production process method |
Families Citing this family (23)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| LU88246A1 (en) * | 1993-04-14 | 1994-12-01 | Magotteaux Int | Method for manufacturing composite wearing parts and parts produced by this method |
| LU88549A1 (en) * | 1994-10-24 | 1995-02-01 | Magotteaux Int | Method for manufacturing a bimetallic grinding roller and grinding roller obtained by the implementation of this process |
| DE19528512C2 (en) * | 1995-08-03 | 2001-02-22 | Swb Stahlformgusgmbh | Wear parts and process for their manufacture |
| AU7734796A (en) * | 1995-12-26 | 1997-07-17 | Combustion Engineering Inc. | Energy-efficient grinding rolls for coal pulverizers |
| LU88753A1 (en) * | 1996-04-30 | 1996-10-04 | Magotteaux Int | Track for shredders |
| SK284900B6 (en) * | 1996-10-01 | 2006-02-02 | Magotteaux International S. A. | Abrasion-resistant part from composite material |
| EP0838288A1 (en) * | 1996-10-01 | 1998-04-29 | Hubert Francois | Wear resistant composite cast pieces |
| LU90006B1 (en) * | 1997-01-15 | 1997-08-21 | Magotteaux Int | Insert for composite wearing parts process for manufacturing a wearing part using such inserts and wearing part thus produced |
| KR100860249B1 (en) | 2001-12-04 | 2008-09-25 | 마고또 앵떼르나씨오날 에스.에이. | Cast part with enhanced wear resistance and method for production thereof |
| EP1570905A1 (en) * | 2004-03-03 | 2005-09-07 | Magotteaux International S.A. | Grinding roller for a roller mill |
| SE532815C2 (en) * | 2007-11-09 | 2010-04-13 | Combi Wear Parts Ab | Self-sharpening, auto-signaling wear part |
| BE1018129A3 (en) | 2008-09-19 | 2010-05-04 | Magotteaux Int | COMPOSITE IMPACTOR FOR PERCUSSION CRUSHERS. |
| BE1021839B1 (en) * | 2014-04-23 | 2016-01-21 | Magotteaux International S.A. | MILLING ROLL COMPRISING HIGH MASS INSERTS |
| CN103977864A (en) * | 2014-06-11 | 2014-08-13 | 南京凯盛国际工程有限公司 | Novel vertical mill roll sleeve |
| CN105413804A (en) * | 2015-12-03 | 2016-03-23 | 中钢集团安徽天源科技股份有限公司 | High-pressure grinding roller roll surface structure and manufacturing method |
| CN107552767A (en) * | 2017-08-24 | 2018-01-09 | 昆明理工大学 | A kind of manufacture craft of novel wear-resistant bucket tooth |
| CN111112583B (en) * | 2020-01-06 | 2021-09-24 | 南通高欣耐磨科技股份有限公司 | Manufacturing method of low-cost and repairable ceramic alloy composite grinding roller |
| CN111408702A (en) * | 2020-04-07 | 2020-07-14 | 聂章银 | Bimetal casting mould convenient to move |
| CN111618277B (en) * | 2020-04-22 | 2021-09-21 | 南通高欣耐磨科技股份有限公司 | Manufacturing method of easily-detachable, easily-machined and repairable high-wear-resistance ceramic alloy composite grinding roller |
| CN111590053B (en) * | 2020-04-22 | 2021-09-03 | 南通高欣耐磨科技股份有限公司 | Manufacturing method of easily-machined and repairable high-wear-resistance metal ceramic composite grinding roller |
| CN111571121B (en) * | 2020-04-22 | 2021-09-21 | 南通高欣耐磨科技股份有限公司 | Manufacturing method of easily-detachable and repairable high-wear-resistance ceramic alloy composite grinding roller |
| CN113368959A (en) * | 2021-06-11 | 2021-09-10 | 郑州机械研究所有限公司 | Wear-resistant structure without damaging parent and preparation method thereof |
| CN114950636B (en) * | 2022-06-06 | 2024-04-26 | 唐山迁西大方科技有限公司 | Armor nail roller sleeve and preparation method thereof |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2155215A (en) * | 1936-02-27 | 1939-04-18 | Beament Thomas Geoffrey | Method of producing composite wear-resisting bodies |
| LU64303A1 (en) * | 1971-11-22 | 1971-12-05 | ||
| US4099988A (en) * | 1976-02-26 | 1978-07-11 | Kawasaki Jukogyo Kabushiki Kaisha | Composite material having wear- and impact-resisting surface and process for producing same |
| AT375035B (en) * | 1979-12-13 | 1984-06-25 | Ver Edelstahlwerke Ag | METHOD FOR THE PRODUCTION OF METAL CHIMED MOLDED PARTS |
| JPS63143949A (en) * | 1986-12-09 | 1988-06-16 | アイエヌジ商事株式会社 | Crushing surface member used for crusher |
| DE3814433A1 (en) * | 1988-04-28 | 1989-11-09 | Krupp Polysius Ag | Roller mill and method for coating a roller |
-
1990
- 1990-09-20 BE BE9000895A patent/BE1004573A4/en not_active IP Right Cessation
-
1991
- 1991-01-31 JP JP3032033A patent/JP2799250B2/en not_active Expired - Fee Related
- 1991-09-11 DE DE69107746T patent/DE69107746T2/en not_active Expired - Fee Related
- 1991-09-11 DK DK91115332.8T patent/DK0476496T3/en active
- 1991-09-11 EP EP91115332A patent/EP0476496B1/en not_active Expired - Lifetime
- 1991-09-11 ES ES91115332T patent/ES2069156T3/en not_active Expired - Lifetime
- 1991-09-11 AT AT91115332T patent/ATE119092T1/en not_active IP Right Cessation
- 1991-09-12 CA CA002051221A patent/CA2051221C/en not_active Expired - Fee Related
- 1991-09-19 KR KR1019910016444A patent/KR0149031B1/en not_active IP Right Cessation
- 1991-09-19 PT PT99013A patent/PT99013B/en not_active IP Right Cessation
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103056343A (en) * | 2012-12-21 | 2013-04-24 | 佳木斯大学 | Trimetal composite cast crusher hammer production process method |
| CN103056343B (en) * | 2012-12-21 | 2014-11-26 | 佳木斯大学 | Trimetal composite cast crusher hammer production process method |
Also Published As
| Publication number | Publication date |
|---|---|
| DK0476496T3 (en) | 1995-07-17 |
| PT99013B (en) | 1999-02-26 |
| ATE119092T1 (en) | 1995-03-15 |
| JPH04231164A (en) | 1992-08-20 |
| CA2051221A1 (en) | 1992-03-21 |
| ES2069156T3 (en) | 1995-05-01 |
| KR0149031B1 (en) | 1998-11-16 |
| KR920006061A (en) | 1992-04-27 |
| BE1004573A4 (en) | 1992-12-15 |
| DE69107746D1 (en) | 1995-04-06 |
| JP2799250B2 (en) | 1998-09-17 |
| EP0476496A1 (en) | 1992-03-25 |
| EP0476496B1 (en) | 1995-03-01 |
| DE69107746T2 (en) | 1995-06-29 |
| PT99013A (en) | 1993-10-29 |
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