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WO1996005005A1 - Bimetal foundery part used as a wear part in vertical crushers, fabrication method and utilisation in vertical crushers - Google Patents

Bimetal foundery part used as a wear part in vertical crushers, fabrication method and utilisation in vertical crushers Download PDF

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Publication number
WO1996005005A1
WO1996005005A1 PCT/BE1995/000074 BE9500074W WO9605005A1 WO 1996005005 A1 WO1996005005 A1 WO 1996005005A1 BE 9500074 W BE9500074 W BE 9500074W WO 9605005 A1 WO9605005 A1 WO 9605005A1
Authority
WO
WIPO (PCT)
Prior art keywords
core
hub
part according
studs
ductile
Prior art date
Application number
PCT/BE1995/000074
Other languages
French (fr)
Inventor
Norbert Guerard
Original Assignee
Magotteaux International S.A.
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Magotteaux International S.A. filed Critical Magotteaux International S.A.
Priority to KR1019970700766A priority Critical patent/KR970704536A/en
Priority to DK95928904T priority patent/DK0777542T3/en
Priority to DE69504691T priority patent/DE69504691T2/en
Priority to MX9701225A priority patent/MX9701225A/en
Priority to EP95928904A priority patent/EP0777542B1/en
Publication of WO1996005005A1 publication Critical patent/WO1996005005A1/en

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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
    • 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
    • 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
    • B22D19/02—Casting in, on, or around objects which form part of the product for making reinforced articles
    • 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

Definitions

  • the present invention relates to a bimetallic foundry piece serving as a wearing part in mills, in particular so-called vertical mills. It also applies to a process for producing such a part and to its use in grinders of this type.
  • the vertical crushers consist of rollers rotating around a vertical axis on a grinding track.
  • the grinding rollers are mounted on a central hub and are provided at their periphery with wearing parts which may be in the form of segments or which may also be formed in a single piece.
  • wear parts are made of cast iron having a high resistance to abrasion, in particular castings with high chromium content and, consequently, are very little ductile (their value of elongation at break is practically equal to zero). Wear parts are generally secured using clamps to the hub. precisely from their lack of ductility, it is possible to observe, under the stresses due to the various mechanical stresses, the appearance in particular of cracks which propagate in said parts.
  • Various other drawbacks are manifested, including, under the effect of the constraints, in particular a deformation of the hub. This deformation of the hub causes considerable difficulty when replacing wearing parts and it is common to have to replace both the wearing part and the hub.
  • the wearing part is particularly difficult to machine after casting because of its specific properties, namely its high hardness, while tolerances less than H9 are required for these machining operations.
  • the combined metallurgical-mechanical connection is described as making it possible to compensate for the tensions resulting from the differences in coefficient of expansion between the base alloy (graphite cast iron) and the reinforcement material incorporated in the wear part, thus ensuring a good connection. between this wear part and the weldable part and avoiding the propagation of micro-cracks.
  • the invention essentially aims to propose a new design of wear parts of mills of the type mentioned which ensures a series of specific advantages, in particular better resistance to cracking, an absence of deformation of the hub under the applied stresses and of in general, greater flexibility in the system for attaching wear parts to the hub.
  • the invention relates to a bimetallic foundry part intended for vertical mills comprising a core made of ductile cast iron provided with mechanical connection elements advantageously in the form of studs, which are fixed to an envelope made of non-wearing material. ductile with high chromium content.
  • This type of part can be in the form of segments or in the form of a one-piece element, with a view to their mounting on the hub of the vertical grinder rollers.
  • the connecting part which is the most highly stressed consists of studs coming from casting in the core of ductile iron, which contributes to the mechanical strength of the assembly.
  • the forces generated by the grinding work - instead of being transmitted directly from the wear part to the hub - are here taken up first by the studs and then by the ductile iron core.
  • cracks or cracks which may appear on the external periphery of the wearing part do not propagate in the total mass of the wearing part.
  • the deformations observed in the technique of hard mono-metallic wearing parts on a soft hub are thus avoided.
  • the laying surface of the wear part which must be machined to adapt perfectly to the hub is constituted in this case by ductile iron which greatly facilitates machining.
  • the ductile iron used is preferably a type GS iron (GGG 40 according to DIN 1693).
  • the specific shape of the studs is preferably chosen so as to provide simplified threads of rounded shape.
  • the parts according to the invention also make it possible to facilitate the weighting of the part in chromium cast iron and to obtain better mechanical properties thanks to the cooling effect of the part in ductile cast iron. It should be noted that the bimetallic parts thus produced thus avoid the use of a metallurgical bonding solution. This avoids the well-known drawback of a horizontal separation surface between the two cast metals.
  • the studs can have the shape of a dovetail.
  • the process for manufacturing such a part is particularly advantageous due to the choice of materials used which makes it possible to first cast the core with the studs in a first mold and then, after having applied a refractory coating intended to prevent a metallurgical bond, to sink the envelope. Finally, a quenching heat treatment is carried out taking into account the nature of the constituent elements of the part and possibly the intended use, in particular the grinder and the materials to be ground, according to the criteria well known to specialists in these materials.
  • the invention will be described in more detail with reference to a preferred embodiment thereof, with reference to the accompanying drawings. Other details and characteristic elements of the invention will appear on reading the description which follows.
  • Figure 1 schematically shows the arrangement of a grinding roller in a vertical axis mill.
  • FIG. 2 shows, by way of illustration of a particular form of the invention, a roller segment according to the invention
  • Figure 3 is a section AB in the embodiment of Figure 2;
  • Figures 4 and 5 show an example of a part produced according to the invention, Figure 4 being a section along CD of Figure 5.
  • a roller 3 is driven relative to the axis 1 by turning through a hub 2 shown schematically on an axis 5 which can be slightly inclined (as shown) or horizontal, in order to grind the material supplied between the roller and the grinding track 6.
  • the mark 7 represents the material to be ground fed centrally in the mill. After grinding, the fine particles are extracted from the grinder and the larger ones are returned to the grinding track 6 by a stream of air shown diagrammatically by the arrow 9.
  • roller 3 is rounded on its peripheral part and the track has a corresponding shape.
  • the wear part properly speaking bearing the general reference 11 is formed by a core 13 comprising studs 15 obtained from foundry on which an envelope 17 is cast.
  • the essential characteristic of the invention is the fact that the core 13 and connecting elements in the form of studs 15 from casting are formed from a ductile material, namely GS cast iron, while the casing 17 is made from non-ductile alloys, in particular chromium cast irons of hardness ⁇ 64 Rc usually used as wear parts .
  • the offset of the casing 17 relative to the core 13 can be adapted to the different requirements of the manufacturers in a simple manner, all the more so as the peripheral junction line 21 between the casing 17 and the core 13 is located advantageously in the internal angle of recess, which avoids exposure of this line to the direct action of the material to be ground.
  • the method used for producing the wearing part according to the invention consists in first casting the core 13 with the studs 15; after having applied a refractory coating on the core, the part is placed in a second mold and the casing 17 is poured. The assembly is then subjected to a thermal quenching treatment.
  • a thermal quenching treatment In order to illustrate the invention, an example of the execution of a part according to the invention and the results of laboratory tests obtained will be described below.
  • the casting of Figures 4 and 5 is a bimetallic block of 230x275x150mm formed by a part corresponding to the core 13 and the studs 15 in GS cast iron (GGG40) and by an envelope part there in chromium cast iron with a hardness greater than or equal to 64 Rc.
  • GGG40 GS cast iron
  • chromium cast iron with a hardness greater than or equal to 64 Rc.
  • a refractory coating (not shown) is applied to this part to avoid reflow of the studs and the risk of a metallurgical bond with chromium cast iron.
  • chrome cast iron was poured on it.
  • the bimetal block was then trimmed and quenched. Fatigue tests were performed.
  • the tests are carried out in a SCHENK machine with a maximum capacity of 2500 kN.
  • the applied signal is sinusoidal.
  • the assembly underwent an oscillating compression load 100kN-2000kN generating maximum contact pressures 3 times higher than those undergone by a roller in service.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Food Science & Technology (AREA)
  • Crushing And Grinding (AREA)
  • Crushing And Pulverization Processes (AREA)
  • Adornments (AREA)
  • Polishing Bodies And Polishing Tools (AREA)

Abstract

The invention relates to a bimetal foundery part used as a wearing part in vertical crushers and its method of fabrication. The part comprises a core (13) made of a ductile cast iron provided with mechanical link elements such as bolts (15) which are made integral by casting of an envelope (17) made of a non ductile wearing material having a high chromium content. Such parts are intended to be mounted on the hub of a roller of a vertical axis crusher.

Description

PIÈCE DE FONDERIE BIMÉTALLIQUE SERVANT DE PIÈCE D'USURE DANS LES BROYEURS VERTICAUX, SON PROCÉDÉ DE FABRICATION ET UTILISATION DANS LES BROYEURS TWO-METAL FOUNDRY PIECE FOR USE IN A VERTICAL CRUSHER, ITS MANUFACTURING METHOD AND USE IN GRINDERS
VERTICAUXVERTICALS
OBJET DE L'INVENTIONOBJECT OF THE INVENTION
La présente invention concerne une pièce de fonderie bimétallique servant de pièce d'usure dans des broyeurs, en particulier des broyeurs dits verticaux. Elle s'applique également à un procédé de réalisation d'une telle pièce et à son utilisation dans des broyeurs de ce type.The present invention relates to a bimetallic foundry piece serving as a wearing part in mills, in particular so-called vertical mills. It also applies to a process for producing such a part and to its use in grinders of this type.
Arrière plan technologique de l'inventionTechnological background of the invention
Les broyeurs verticaux sont constitués par des galets tournant autour d'un axe vertical sur une piste de broyage. Les galets de broyage sont montés sur un moyeu central et sont pourvus à leur périphérie de pièces d'usure qui peuvent se présenter sous forme de segments ou qui peuvent être également constituées sous forme monobloc.The vertical crushers consist of rollers rotating around a vertical axis on a grinding track. The grinding rollers are mounted on a central hub and are provided at their periphery with wearing parts which may be in the form of segments or which may also be formed in a single piece.
Ces pièces d'usure sont réalisées en fonte présentant une forte résistance à l'abrasion, notamment des fontes à haute teneur en chrome et, par conséquent sont très peu ductiles (leur valeur d'allongement de rupture est pratiquement égale à zéro) . Les pièces d'usure sont généralement solidarisées à l'aide de clames au moyeu.A cause précisément de leur absence de ductilité, on peut observer sous les contraintes dues aux diverses sollicitations mécaniques l'apparition notamment de fissures qui se propagent dans les dites pièces. Divers autres inconvénients se manifestent dont, sous l'effet des contraintes, notamment une déformation du moyeu. Cette déformation du moyeu cause de considérables difficultés lors du remplacement des pièces d'usure et il est courant de devoir remplacer à la fois la pièce d'usure et le moyeu. De plus, la pièce d'usure est particulièrement difficile à usiner après coulée à cause de ses propriétés spécifiques, à savoir sa haute dureté, alors que des tolérances inférieures à H9 sont exigées pour ces usinages.These wear parts are made of cast iron having a high resistance to abrasion, in particular castings with high chromium content and, consequently, are very little ductile (their value of elongation at break is practically equal to zero). Wear parts are generally secured using clamps to the hub. precisely from their lack of ductility, it is possible to observe, under the stresses due to the various mechanical stresses, the appearance in particular of cracks which propagate in said parts. Various other drawbacks are manifested, including, under the effect of the constraints, in particular a deformation of the hub. This deformation of the hub causes considerable difficulty when replacing wearing parts and it is common to have to replace both the wearing part and the hub. In addition, the wearing part is particularly difficult to machine after casting because of its specific properties, namely its high hardness, while tolerances less than H9 are required for these machining operations.
Dans le document GB-2 078 575 A on décrit des pièces d'usure soudables constituées d'une partie en acier soudable pourvue de protusions qui, après avoir été placée dans une moule est soumise à une liaison étallurgico-mécanique obtenue en coulant une fonte. Ces pièces sont décrites comme pouvant convenir à divers usages telles que des pièces de machine et des outils. On propose d'utiliser pour la partie d'usure coulée une fonte graphitique sphéroïdale de faible résistance à l'usure et de faible soudabilité dans laquelle un métal dur est incorporé.Document GB-2 078 575 A describes weldable wear parts consisting of a weldable steel part provided with protrusions which, after being placed in a mold, is subjected to a mechanical-mechanical bond obtained by casting a cast iron . These parts are described as being suitable for various uses such as machine parts and tools. It is proposed to use for the wear portion cast a spheroidal graphitic cast iron of low wear resistance and low weldability in which a hard metal is incorporated.
La liaison combinée métallurgico-mécanique est décrite comme permettant de compenser les tensions résultant des différences de coefficient de dilatation entre l'alliage de base (fonte graphitique) et la matière de renforcement incorporée dans la partie d'usure, en assurant ainsi une bonne liaison entre cette partie d'usure et la partie soudable et en évitant la propagation des micro-fissures.The combined metallurgical-mechanical connection is described as making it possible to compensate for the tensions resulting from the differences in coefficient of expansion between the base alloy (graphite cast iron) and the reinforcement material incorporated in the wear part, thus ensuring a good connection. between this wear part and the weldable part and avoiding the propagation of micro-cracks.
La Demanderesse s'est cependant aperçue que cette solution n'est pas totalement satisfaisante d'une part parce qu'elle limite l'utilisation de compositions très dures pour la partie d'usure puisqu'il faut assurer cette liaison métallurgico-mécanique et d'autre part parce qu'une telle liaison n'empêche pas suffisamment la propagation des fissures et des micro-fissures. Ce phénomène est particulièrement observé dans le cas de grands broyeurs verticaux décrits ci-dessus.The Applicant has however noticed that this solution is not entirely satisfactory on the one hand because it limits the use of very hard compositions for the wear part since this metallurgical-mechanical connection and on the other hand because such a bond does not sufficiently prevent the propagation of cracks and micro-cracks. This phenomenon is particularly observed in the case of large vertical mills described above.
Buts visés par l'inventionGoals of the invention
L'invention vise essentiellement à proposer une conception nouvelle des pièces d'usure de broyeurs du type mentionné qui assure une série d'avantages spécifiques, en particulier une meilleure résistance à la fissuration, une absence de déformation du moyeu sous les contraintes appliquées et de manière générale, une plus grande souplesse dans le système de fixation des pièces d'usure au moyeu.The invention essentially aims to propose a new design of wear parts of mills of the type mentioned which ensures a series of specific advantages, in particular better resistance to cracking, an absence of deformation of the hub under the applied stresses and of in general, greater flexibility in the system for attaching wear parts to the hub.
On vise également à réaliser d'importantes économies au niveau du prix de fabrication et de la durée de vie des pièces.We also aim to achieve significant savings in terms of manufacturing price and service life of parts.
D'autres buts et avantages de l'invention apparaîtront à la lecture du mémoire descriptif et des revendications.Other objects and advantages of the invention will appear on reading the specification and the claims.
Eléments caractéristiques de l'inventionCharacter-defining elements of the invention
L'invention concerne une pièce de fonderie bimétallique destinée à des broyeurs verticaux comportant un noyau réalisé en une fonte ductile pourvu d'éléments de liaison mécanique avantageusement sous forme de goujons, lesquels sont fixés à une enveloppe réalisée en un matériau d'usure non-ductile à haute teneur en chrome.The invention relates to a bimetallic foundry part intended for vertical mills comprising a core made of ductile cast iron provided with mechanical connection elements advantageously in the form of studs, which are fixed to an envelope made of non-wearing material. ductile with high chromium content.
Ce type de pièce peut se présenter sous forme de segments ou sous forme d'un élément monobloc, en vue de leur montage sur le moyeu des galets de broyeurs verticaux.This type of part can be in the form of segments or in the form of a one-piece element, with a view to their mounting on the hub of the vertical grinder rollers.
Dans le cas du montage de segments, ceci peut se réaliser par clamage ou boulonnage sur le moyeu; dans le cas d'éléments monobloc, l'assemblage a lieu par frettage, sans nécessité de souder ces éléments sur le moyeu dans aucun des cas.In the case of mounting segments, this can be achieved by clamping or bolting on the hub; in the case of monobloc elements, assembly takes place by shrinking, without the need to weld these elements on the hub in any of the cases.
Dans un cas comme dans l'autre, les risques de fissuration sont fortement réduits même sous des conditions de contraintes importantes puisque la zone de fixation des boulons ou des clames de solidarisation avec le moyeu est située dans la partie du noyau en fonte ductile.In one case as in the other, the risks of cracking are greatly reduced even under conditions of significant stress since the area of attachment of the bolts or clamps securing to the hub is located in the part of the ductile iron core.
De même la partie de liaison qui est la plus fortement sollicitée est constituée par des goujons venus de coulée dans le noyau en fonte ductile, ce qui contribue à la résistance mécanique de l'ensemble.Likewise, the connecting part which is the most highly stressed consists of studs coming from casting in the core of ductile iron, which contributes to the mechanical strength of the assembly.
Les efforts générés par le travail de broyage - au lieu d'être transmis directement de la pièce d'usure sur le moyeu - sont ici repris d'abord par les goujons et ensuite par le noyau en fonte ductile.Ceci a pour conséquence d'une part que des fissurations ou des criques pouvant apparaître sur la périphérie externe de la pièce d'usure ne se propagent pas dans la masse totale de la pièce d'usure. De plus, les déformations observées dans la technique des pièces d'usure mono-métalliques dures sur un moyeu doux sont ainsi évitées. Finalement, la surface de pose de la pièce d'usure qui doit être usinée pour s'adapter parfaitement au moyeu est constituée dans le cas présent par une fonte ductile ce qui facilite nettement l'usinage. De manière générale, on observe une économie générale par la réduction du prix d'usinage, l'utilisation d'une pièce moins lourde, l'économie d'éléments d'alliage et une grande souplesse d'utilisation permettant de fixer la pièce d'usure bimétallique aussi bien par clamage que par boulonnage, ou dans le cas d'un élément monobloc, par frettage.The forces generated by the grinding work - instead of being transmitted directly from the wear part to the hub - are here taken up first by the studs and then by the ductile iron core. on the one hand that cracks or cracks which may appear on the external periphery of the wearing part do not propagate in the total mass of the wearing part. In addition, the deformations observed in the technique of hard mono-metallic wearing parts on a soft hub are thus avoided. Finally, the laying surface of the wear part which must be machined to adapt perfectly to the hub is constituted in this case by ductile iron which greatly facilitates machining. In general, there is a general saving by reducing the machining price, the use of a lighter part, the saving of alloying elements and a great flexibility of use allowing the part to be fixed. 'bi-metallic wear as well by clamming as by bolting, or in the case of a monobloc element, by shrinking.
La fonte ductile utilisée est de préférence une fonte du type GS (GGG 40 suivant la norme DIN 1693) .The ductile iron used is preferably a type GS iron (GGG 40 according to DIN 1693).
De même on dispose d'une plus grande liberté d'exécution des formes spécifiques non seulement parce qu'elles sont plus faciles à usiner mais également parce que les pièces selon cette conception particulière sont moins sollicitées mécaniquement et que, dans leur conception, il n'y a plus lieu de tenir compte dans la même mesure des efforts importants transmis. Ceci permet donc d'adapter la forme spécifique des pièces d'usure aux différents types de construction de broyeur vertical à galets. Le décrochement qui est généralement prévu au pied de la pièce d'usure pour son raccordement au moyeu peut être adapté aux exigences de chaque constructeur.Likewise, there is greater freedom of execution of the specific shapes not only because they are easier to machine but also because the parts according to this particular design are less mechanically stressed and that, in their design, there is no 'There is no longer any reason to take into account the significant efforts transmitted to the same extent. This therefore makes it possible to adapt the specific shape of the wearing parts to the different types of vertical roller mill construction. The step which is generally provided at the foot of the wear part for its connection to the hub can be adapted to the requirements of each manufacturer.
La forme spécifique des goujons est de préférence choisie de manière à prévoir des filets simplifiés de forme arrondie.The specific shape of the studs is preferably chosen so as to provide simplified threads of rounded shape.
Les pièces selon l'invention permettent également de faciliter le masselottage de la partie en fonte au chrome et d'obtenir des meilleures propriétés mécaniques grâce à l'effet refroidisseur de la partie en fonte ductile. Il convient de noter que les pièces bimétalliques ainsi réalisées évitent ainsi, le recours à une solution de liaison métallurgique. Ceci permet d'éviter l'inconvénient bien connu d'une surface de séparation horizontale entre les deux métaux coulés.The parts according to the invention also make it possible to facilitate the weighting of the part in chromium cast iron and to obtain better mechanical properties thanks to the cooling effect of the part in ductile cast iron. It should be noted that the bimetallic parts thus produced thus avoid the use of a metallurgical bonding solution. This avoids the well-known drawback of a horizontal separation surface between the two cast metals.
De plus, l'absence de liaison métallurgique évite la propagation de la fissuration apparaissant dans la pièce d'usure périphérique dans le noyau.In addition, the absence of metallurgical bond prevents the propagation of the cracking appearing in the peripheral wear part in the core.
L'utilisation d'une forme arrondie pour les filets des goujons évite l'amorce de criques et contribue donc à une durée de vie prolongée des pièces.The use of a rounded shape for the threads of the studs avoids the initiation of cracks and therefore contributes to an extended service life of the parts.
Selon une forme d'exécution spécifique de l'invention, les goujons peuvent affecter la forme d'une queue d'aronde.According to a specific embodiment of the invention, the studs can have the shape of a dovetail.
Le procédé pour la fabrication d'une telle pièce est particulièrement intéressant par suite du choix des matériaux mis en oeuvre qui permet de couler d'abord le noyau avec les goujons dans un premier moule et ensuite, après avoir appliqué un enduit réfractaire destiné à empêcher une liaison métallurgique, de couler l'enveloppe. On procède finalement à un traitement thermique de trempe tenant compte de la nature des éléments constitutifs de la pièce et éventuellement de l'usage envisagé, en particulier du broyeur et des matériaux à broyer, selon les critères bien connus des spécialistes de ces matériaux. L'invention sera décrite plus en détail en référence à une forme d'exécution préférée de celle-ci, au regard des dessins annexés. D'autres détails et éléments caractéristiques de l'invention apparaîtront à la lecture de la description qui suit.The process for manufacturing such a part is particularly advantageous due to the choice of materials used which makes it possible to first cast the core with the studs in a first mold and then, after having applied a refractory coating intended to prevent a metallurgical bond, to sink the envelope. Finally, a quenching heat treatment is carried out taking into account the nature of the constituent elements of the part and possibly the intended use, in particular the grinder and the materials to be ground, according to the criteria well known to specialists in these materials. The invention will be described in more detail with reference to a preferred embodiment thereof, with reference to the accompanying drawings. Other details and characteristic elements of the invention will appear on reading the description which follows.
Brève description des dessinsBrief description of the drawings
La figure 1 représente schématiquement la disposition d'un galet de broyage dans un broyeur à axe vertical.Figure 1 schematically shows the arrangement of a grinding roller in a vertical axis mill.
La figure 2 représente à titre d'illustration d'une forme particulière de l'invention, un segment de galet selon l'invention; La figure 3 est une section AB dans la forme d'exécution de la figure 2;FIG. 2 shows, by way of illustration of a particular form of the invention, a roller segment according to the invention; Figure 3 is a section AB in the embodiment of Figure 2;
Les figures 4 et 5 reprennent un exemple d'une pièce réalisée selon l'invention, la figure 4 étant une coupe suivant CD de la figure 5. En se référant à la figure 1, on a indiqué par le repère 1 l'axe de rotation central du broyeur dit à axe vertical. De manière en soi connue, un galet 3 est entraîné par rapport à l'axe 1 en tournant grâce à un moyeu 2 représenté schématiquement sur un axe 5 qui peut être légèrement incliné (comme représenté) ou horizontal, en vue de broyer la matière alimentée entre le galet et la piste de broyage 6. Le repère 7 représente la matière à broyer alimentée centralement dans le broyeur. Après broyage, les particules fines sont extraites du broyeur et les plus grosses sont renvoyées vers la piste de broyage 6 par un courant d'air schématisé par la flèche 9.Figures 4 and 5 show an example of a part produced according to the invention, Figure 4 being a section along CD of Figure 5. Referring to Figure 1, we indicated by the reference 1 the axis of central rotation of the mill said to vertical axis. In known manner, a roller 3 is driven relative to the axis 1 by turning through a hub 2 shown schematically on an axis 5 which can be slightly inclined (as shown) or horizontal, in order to grind the material supplied between the roller and the grinding track 6. The mark 7 represents the material to be ground fed centrally in the mill. After grinding, the fine particles are extracted from the grinder and the larger ones are returned to the grinding track 6 by a stream of air shown diagrammatically by the arrow 9.
Ainsi qu'on le notera, le galet 3 est arrondi sur sa partie périphérique et la piste présente une forme correspondante. La pièce d'usure à proprement parler portant le repère général 11 est formée par un noyau 13 comportant des goujons 15 obtenus de fonderie sur lesquels est coulée une enveloppe 17.As will be noted, the roller 3 is rounded on its peripheral part and the track has a corresponding shape. The wear part properly speaking bearing the general reference 11 is formed by a core 13 comprising studs 15 obtained from foundry on which an envelope 17 is cast.
La caractéristique essentielle de l'invention est le fait que le noyau 13 et des éléments de liaison sous forme de goujons 15 venus de coulée sont formés en un matériau ductile, à savoir de la fonte GS tandis que l'enveloppe 17 est réalisée dans les alliages non-ductiles en particulier des fontes au chrome de dureté ≥ 64 Rc utilisées habituellement comme pièces d'usure.The essential characteristic of the invention is the fact that the core 13 and connecting elements in the form of studs 15 from casting are formed from a ductile material, namely GS cast iron, while the casing 17 is made from non-ductile alloys, in particular chromium cast irons of hardness ≥ 64 Rc usually used as wear parts .
Il convient de noter que le décrochement de l'enveloppe 17 par rapport au noyau 13 peut être adapté aux différentes exigences des constructeurs de manière simple, d'autant que la ligne de jonction périphérique 21 entre l'enveloppe 17 et le noyau 13 se situe avantageusement dans l'angle interne de décrochement, ce qui évite une exposition de cette ligne à l'action directe de la matière à broyer.It should be noted that the offset of the casing 17 relative to the core 13 can be adapted to the different requirements of the manufacturers in a simple manner, all the more so as the peripheral junction line 21 between the casing 17 and the core 13 is located advantageously in the internal angle of recess, which avoids exposure of this line to the direct action of the material to be ground.
On réalise de cette manière un concept constructif particulièrement simple. Pratiquement la moitié de la masse de ce qui constituait antérieurement une pièce d'usure mono-métallique fixée sur un moyeu, est, selon l'invention constituée par le noyau ductile, ce qui entraîne une économie importante d'éléments d'alliage onéreux. II convient de noter que si l'on a décrit une forme d'exécution de la pièce d'usure sous forme de segments, il est également possible de constituer une frette monobloc selon le concept inventif de l'invention.In this way a particularly simple constructive concept is realized. Almost half the mass of what previously constituted a mono-metallic wear part fixed to a hub, is, according to the invention, constituted by the ductile core, which results in a significant saving in expensive alloying elements. It should be noted that if an embodiment of the wearing part has been described in the form of segments, it is also possible to constitute a one-piece hoop according to the inventive concept of the invention.
Le procédé mis en oeuvre pour la réalisation de la pièce d'usure selon l'invention consiste à couler en premier lieu le noyau 13 avec les goujons 15; après avoir appliqué un enduit refractaire sur le noyau, on place la pièce dans un second moule et on coule l'enveloppe 17. L'ensemble subit ensuite un traitement thermique de trempe. Afin d'illustrer l'invention on décrira ci-après un exemple d'exécution d'une pièce selon l'invention et les résultats d'essais de laboratoire obtenus.The method used for producing the wearing part according to the invention consists in first casting the core 13 with the studs 15; after having applied a refractory coating on the core, the part is placed in a second mold and the casing 17 is poured. The assembly is then subjected to a thermal quenching treatment. In order to illustrate the invention, an example of the execution of a part according to the invention and the results of laboratory tests obtained will be described below.
Exemple l Essai bimétal à liaison mécaniqueExample l Mechanical bonded bimetal test
La pièce coulée des figures 4 et 5 est un bloc bimétallique de 230x275x150mm formé par une partie correspondant au noyau 13 et aux goujons 15 en fonte GS (GGG40) et par une partie d'enveloppe il en fonte au chrome d'une dureté supérieure ou égale à 64 Rc.The casting of Figures 4 and 5 is a bimetallic block of 230x275x150mm formed by a part corresponding to the core 13 and the studs 15 in GS cast iron (GGG40) and by an envelope part there in chromium cast iron with a hardness greater than or equal to 64 Rc.
Après ébarbage, un enduit réfractaire (non représenté) est appliqué sur cette partie pour éviter la refusion des goujons et le risque d'une liaison métallurgique avec la fonte au chrome.After deburring, a refractory coating (not shown) is applied to this part to avoid reflow of the studs and the risk of a metallurgical bond with chromium cast iron.
Après avoir placé ce bloc dans un second moule, la fonte au chrome a été coulée sur celui-ci.After placing this block in a second mold, chrome cast iron was poured on it.
Le bloc bimétal a ensuite été, ébarbé et trempé. On a procédé à des essais de fatigue.The bimetal block was then trimmed and quenched. Fatigue tests were performed.
Les essais sont effectués dans une machine SCHENK de capacité maximale de 2500 kN.The tests are carried out in a SCHENK machine with a maximum capacity of 2500 kN.
Le signal appliqué est sinusoidal.The applied signal is sinusoidal.
L'assemblage a subi une charge oscillante de compression 100kN-2000kN générant des pressions maximum de contact 3 fois supérieures à celles subies par un galet en service.The assembly underwent an oscillating compression load 100kN-2000kN generating maximum contact pressures 3 times higher than those undergone by a roller in service.
L'assemblage testé n'a pas subi de dégradation apparente durant 465 000 cycles. The assembly tested did not undergo any apparent degradation during 465,000 cycles.

Claims

REVENDICATIONS
1. Pièce de fonderie bimétallique destinée à des broyeurs verticaux caractérisée en ce qu'elle comporte un noyau (13) réalisé en une fonte ductile pourvu d'éléments de liaison mécanique (15) , avantageusement sous forme de goujons, qui sont rendus solidaires par coulée d'une enveloppe (17) , réalisée en un matériau d'usure non-ductile à haute teneur en chrome.1. Bi-metallic foundry part intended for vertical mills characterized in that it comprises a core (13) made of a ductile iron provided with mechanical connection elements (15), advantageously in the form of studs, which are made integral by casting of an envelope (17), made of a non-ductile wear material with a high chromium content.
2. Pièce selon la revendication 1 caractérisée en ce qu'elle se présente sous forme de segments ou sous forme d'un élément monobloc, en vue de leur montage sur le moyeu des galets de broyeurs verticaux.2. Part according to claim 1 characterized in that it is in the form of segments or in the form of a single piece, for mounting on the hub of the rollers of vertical mills.
3. Pièce selon l'une quelconque des revendications 1 ou 2 caractérisée en ce que les éléments de liaison (15) sont constitués par des goujons venus de coulée du noyau (13) en fonte ductile.3. Part according to any one of claims 1 or 2 characterized in that the connecting elements (15) consist of studs from casting the core (13) in ductile iron.
4. Pièce selon l'une quelconque des revendications 1 à 3 caractérisée en ce que la fonte ductile utilisée est une fonte du type GS. 4. Part according to any one of claims 1 to 3 characterized in that the ductile iron used is a GS type cast iron.
5. Pièce selon l'une quelconque des revendications 1 à 4 caractérisée en ce que le matériau d'usure non ductible est une fonte au chrome de dureté supérieure ou égale à 64 Rc.5. Part according to any one of claims 1 to 4 characterized in that the non-ductible wear material is a chromium cast iron with a hardness greater than or equal to 64 Rc.
6. Pièce selon l'une quelconque des revendications 1 à 5 caractérisée en ce qu'on utilise comme éléments de liaison (15) des goujons présentant des filets de forme arrondie.6. Part according to any one of claims 1 to 5 characterized in that one uses as connecting elements (15) studs having threads of rounded shape.
7. Pièce selon l'une quelconque des revendications 1 à 6 caractérisée en ce qu'elle comporte un décrochement périphérique et que la ligne de jonction périphérique (21) entre l'enveloppe (17) et le noyau (13) se situe dans l'angle interne de ce décrochement.7. Part according to any one of claims 1 to 6 characterized in that it comprises a peripheral recess and that the peripheral junction line (21) between the envelope (17) and the core (13) is located in the internal angle of this step.
8. Procédé pour la fabrication d'une pièce selon l'une quelconque des revendications 1 à 7 caractérisé en ce qu'on coule en premier lieu le noyau (13) avec les éléments de liaison (15) , en ce qu'on applique ensuite un enduit réfractaire sur le noyau et éléments de liaison, en ce qu'on place la pièce dans un second moule et coule l'enveloppe (17) et en ce qu'on procède finalement à un traitement thermique de trempe. 8. A method for manufacturing a part according to any one of claims 1 to 7 characterized in that the core is first cast (13) with the connecting elements (15), in that one applies then a coating refractory on the core and connecting elements, in that the part is placed in a second mold and the casing (17) is poured and in that a quenching heat treatment is finally carried out.
9. Utilisation des pièces selon l'une quelconque des revendications 1 à 7 ou obtenues selon le procédé de la revendication 8 caractérisée en ce qu'elle est montée sur le moyeu (2) d'un galet (3) d'un broyeur dit à axe vertical. 9. Use of the parts according to any one of claims 1 to 7 or obtained according to the method of claim 8 characterized in that it is mounted on the hub (2) of a roller (3) of a so-called crusher with vertical axis.
10. Utilisation selon la revendication 9 caracérisée en ce que le montage sur ledit moyeu (2) est réalisé soit par clamage ou boulonnage du noyau (13) sur le moyeu (2) ou encore par frettage du noyau (13) sur le moyeu(2) . 10. Use according to claim 9 characterized in that the mounting on said hub (2) is carried out either by clamping or bolting the core (13) on the hub (2) or by shrinking the core (13) on the hub ( 2).
PCT/BE1995/000074 1994-08-17 1995-08-16 Bimetal foundery part used as a wear part in vertical crushers, fabrication method and utilisation in vertical crushers WO1996005005A1 (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
KR1019970700766A KR970704536A (en) 1994-08-17 1995-08-16 A method for manufacturing a bimetal casting abrasive piece of a vertical crusher, a method of manufacturing the same, and a method for use in a vertical crusher (BIMETAL FOUNDERY PART USED AS A WEAR PART IN VERTICAL CRUSHERS, FABRICATION METHOD AND UTILIZATION IN VERTACAL CRUSHERS)
DK95928904T DK0777542T3 (en) 1994-08-17 1995-08-16 Bimetal casting for use as vertical abrasives in vertical crushers, processes for its manufacture and use in vertical
DE69504691T DE69504691T2 (en) 1994-08-17 1995-08-16 BIMETAL CASTING PIECE AS A WEARING PART IN A VERTICAL CRUSHER, MANUFACTURING METHOD AND USE
MX9701225A MX9701225A (en) 1995-08-16 1995-08-16 Bimetal foundery part used as a wear part in vertical crushers, fabrication method and utilisation in vertical crushers.
EP95928904A EP0777542B1 (en) 1994-08-17 1995-08-16 Bimetal foundery part used as a wear part in vertical crushers, fabrication method and utilisation in vertical crushers

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
BE9400744A BE1008577A6 (en) 1994-08-17 1994-08-17 Room for foundry bimetallic part wear in vertical mills and manufacturing method thereof.
BE9400744 1994-08-17

Publications (1)

Publication Number Publication Date
WO1996005005A1 true WO1996005005A1 (en) 1996-02-22

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PCT/BE1995/000074 WO1996005005A1 (en) 1994-08-17 1995-08-16 Bimetal foundery part used as a wear part in vertical crushers, fabrication method and utilisation in vertical crushers

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EP (1) EP0777542B1 (en)
KR (1) KR970704536A (en)
AT (1) ATE170783T1 (en)
BE (1) BE1008577A6 (en)
DE (1) DE69504691T2 (en)
DK (1) DK0777542T3 (en)
ES (1) ES2122670T3 (en)
WO (1) WO1996005005A1 (en)

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WO1998031467A1 (en) * 1997-01-15 1998-07-23 Magotteaux International S.A. Insert for composite wear pieces, method for making a wear piece using such inserts and resulting wear piece
EP3308861A1 (en) 2016-10-12 2018-04-18 Magotteaux International S.A. Crushing roller
CN108745491A (en) * 2018-06-21 2018-11-06 湖北秦鸿新材料股份有限公司 A kind of coal pulverizer high abrasion roller set and preparation method thereof
US11534822B2 (en) 2020-02-11 2022-12-27 Magotteaux International S.A. Composite wear part
CN117358359A (en) * 2023-12-01 2024-01-09 秦皇岛首启冶金设备有限公司 Split crushing tooth for crushing steel slag and processing technology thereof
CN119387560A (en) * 2024-10-18 2025-02-07 中国科学院金属研究所 A slurry pump front guard plate and preparation method thereof

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JP2023091410A (en) * 2021-12-20 2023-06-30 三菱重工業株式会社 Grinding roller, solid fuel pulverizing device, and method for manufacturing pulverizing roller

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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998031467A1 (en) * 1997-01-15 1998-07-23 Magotteaux International S.A. Insert for composite wear pieces, method for making a wear piece using such inserts and resulting wear piece
EP3308861A1 (en) 2016-10-12 2018-04-18 Magotteaux International S.A. Crushing roller
WO2018069006A1 (en) 2016-10-12 2018-04-19 Magotteaux International S.A. Grinding roller
US11123742B2 (en) 2016-10-12 2021-09-21 Magotteaux International S.A. Grinding roller
CN108745491A (en) * 2018-06-21 2018-11-06 湖北秦鸿新材料股份有限公司 A kind of coal pulverizer high abrasion roller set and preparation method thereof
US11534822B2 (en) 2020-02-11 2022-12-27 Magotteaux International S.A. Composite wear part
CN117358359A (en) * 2023-12-01 2024-01-09 秦皇岛首启冶金设备有限公司 Split crushing tooth for crushing steel slag and processing technology thereof
CN117358359B (en) * 2023-12-01 2024-04-02 秦皇岛首启冶金设备有限公司 Split crushing tooth for crushing steel slag and processing technology thereof
CN119387560A (en) * 2024-10-18 2025-02-07 中国科学院金属研究所 A slurry pump front guard plate and preparation method thereof

Also Published As

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EP0777542A1 (en) 1997-06-11
EP0777542B1 (en) 1998-09-09
ATE170783T1 (en) 1998-09-15
KR970704536A (en) 1997-09-06
BE1008577A6 (en) 1996-06-04
DE69504691T2 (en) 1999-03-18
ES2122670T3 (en) 1998-12-16
DE69504691D1 (en) 1998-10-15
DK0777542T3 (en) 1999-06-07

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