EP3088084A1 - Hard element for grid armoring for a roller press, method for producing the same, and roller for a roller press - Google Patents

Abstract

The wear-resistant hard body (1) according to the invention consists at least partially of a high-strength iron-based alloy and has outer shell (2) or sleeve of a different material. Rolls for roller presses usually have a bandage, often referred to as a roll body into which the hard bodies are introduced as a grid armor. Particularly preferably, the hard body (1) on the outside has a three-sided closed shell (2). Advantageously, the hard body (1) hardly needs to be machined to ensure the fit to the hole in the bandage, since the shell (2) already has this fit. Thus, a defined fit between bandage and hard body (1) with sheath (2) is possible. The hard body (1) according to the invention with sheath (2) or sleeve are also referred to as Bimetallstuds. Furthermore, particularly preferably, the wear-resistant hard bodies (1) have a circular cylindrical shape. Here, the closed end face of the shell (2), which in the installed state to the center of the roll, preferably rounded. Advantageously, a cracking of the bandage due to sharp edges is prevented. The rounding is particularly preferably a spherical shape.

Description

The invention relates to a hard body for the grid armor of the role of a roller press, a method for its production and a roller for a roller press.

A roller press, also called a good-bed roller mill, has two rollers between which a material bed is crushed by high pressure. The high pressure ensures a high wear of the rollers. In order to reduce this, various solutions have been proposed.

In principle, a surface profiling of the rollers has been recognized as being wear-reducing, whereby the profiling can be applied in various ways. For example, in the EP 0 443 195 A1 proposed to apply nubs on the roll surface by welding.

In the DE 10 2010 024 221 A1 a bandage is proposed for a roller press made of a chromium-containing iron alloy. The bandage is designed to improve the wear protection profiled on the outside. In addition to the high cost of the alloy and the application of the bandage is a complex process step, resulting in high total cost.

The DE 41 32 474 A1 proposes to store in the roller surface wear-resistant pieces of material that are harder than the surrounding roll material. The material pieces are preferably plate-shaped or pin-shaped, connected by gluing to the roller and made of hard metal. The disadvantage is the cost of the material pieces of hard metal high and also carbide is too wear resistant and brittle for various applications.

In the document EP 2 239 058 A2 a wear-resistant roller and its manufacture is disclosed. The roller contains a plurality of wear-resistant surface elements, preferably bolts, wherein the free bolt ends project radially from the surface of the roller. The spaces between the bolts are filled with one, the bolt against softer, matrix material, on which in turn regrind is filled. The bolts are welded to the roller and consist at least partially of a high strength iron alloy. A disadvantage is the complex and costly production process of the arrangement.

In the DE 10 2011 104 854 A1 It is proposed to place the hard bodies in a sleeve and insert them into the roller surface. This allows a simplified release of the hard body from the roll surface.

The object of the present invention is to propose an alternative grid armor for a roll of a roller press, which is inexpensive and has a long service life.

According to the invention this object is achieved by a wear-resistant hard body according to claim 1, a roller for a roller press according to claim 11, by a method for producing a hard body according to claim 15 and by the use according to claim 17. Preferred developments of the invention are the subject of dependent claims.

The wear-resistant hard body according to the invention consists at least partially of a high-strength iron-based alloy (IFW) and has a shell or sleeve of another material on the outside. Rolls for roller presses usually have a bandage, often referred to as a roll body into which the hard bodies are introduced as a grid armor.

Particularly preferably, the hard body outside has a three-sided closed shell. Advantageously, the hard body hardly needs to be machined to ensure the fit to the hole in the bandage, since the shell already has this fit. This allows a defined fit between the bandage and the hard body with sheath. The hard bodies according to the invention with sheath or sleeve are also referred to as Bimetallstuds.

Furthermore, particularly preferably, the wear-resistant hard bodies have a circular cylindrical shape. Here, the closed end face of the shell, which in the installed state to the center of the roll, preferably rounded. Advantageously, a cracking of the bandage due to sharp edges is prevented. The rounding is particularly preferably in a spherical shape.

For the purposes of this application, a high-strength iron-based alloy (IFW) is understood to mean a high-strength iron alloy which consists of a material of the composition of the formula Fe _{a E} 1 _{b E} 2 _{c E} 3 _{d E} 4 _e . E1 is one or more elements of the group Cr, V, Mn, Co and Ni, E2 is one or more elements of the group Mo, Nb, Zr, Y, Hf, Ti, Ta and W, E3 is one or more elements of the group Sn , Al, Ga, Pb and E4 include one or more elements of the group Si, P, C and B, where a = 100 - (b + c + d + e) b = 1 to 12 c = 1 to 12 d = 0 to 12 e = 1 to 25 (a, b, c, d, e in atomic%). This may include minor, manufacturing-related additives and impurities. The microstructure of moldings produced from the alloy consists of at least 30-90% by volume of at least one microcrystalline one austenitic cubic face-centered (fcc) phase further containing at least one further microcrystalline phase. The alloy according to the invention is in DE 10 2006 024 358 described. Preferably, the production of the hard body by casting into the shell or sleeve made of another material, preferably copper, copper alloys or steel.

Particularly advantageous material properties can be achieved if the production of the hard body by means of in the DE 10 2010 062 011 B3 described method takes place. This states that after mixing the alloying elements and melting, they are poured into a mold that allows a cooling rate of at least 10 K / s. Subsequently, the material is tempered at least twice immediately after each other, at tempering temperatures between 500 ° C and 600 ° C and holding times during tempering between 30 seconds and 15 minutes. The heating and cooling rates should be at least 15 K / min.

In a further preferred embodiment, the shell of the hard body has means which allow a mounting structure such as e.g. Welding straps or a thread. Advantageously, the hard body can thus be securely fixed in the roll or on the roll edges. Such a mounting structure would hardly be feasible on a hard body. Other possibilities include a recess or circumferential groove for introducing an annular spring. Such a hard body could be removed by welding a tab or similar. for a slide hammer. After the impact of a hard body in the bore of the roller, the spring leads to a frictional connection. More preferably, the sheath has a profiling of the outer surface of the hard body, which allows a pressing into the role of the roller press, similar to a notched nail.

Further preferably, the hard bodies have a core of weldable material, in particular steel, which makes it possible to weld an aid with which the removal of the hard body from the roll is facilitated.

Preferably, there is a positive connection between the shell or sleeve and the part of the hard body located therein. Thus, a release from the shell due to large temperature fluctuations or other influences can be prevented.

In addition, a recess in the outer casing of the casing or sleeve is preferred, in particular on the end face of the hard body, which is directed towards the middle of the roll in the installed state. The recess allows venting of the cavity during insertion into the closely tolerated receiving bore in the roller shell, and thus facilitates the introduction into the bores of the roller shell.

As an alternative to pressing in, the wear-resistant hard bodies are glued into holes in the roller. By using the shell or sleeve, a defined adhesive gap can be achieved. Often forms at the bottom of the hole from an adhesive reservoir, which acts disadvantageous hydraulically. The gluing also unnecessarily lengthens the manufacturing process since the hard bodies can only be glued in after the band has been shrink-wrapped, otherwise the glue would burn. Last but not least, doing without the adhesive is environmentally friendly. The adhesive connection is destroyed anyway during the first run of the rollers.

The sticking of the hard body in the role without the shell or sleeve has a large bond gap due to the high tolerances in the processing of the hard body or an oversize, through which the hard body can be pressed only with high force.

Particularly preferred is the high strength iron alloy (IFW) FeCrMoVC. The advantage of this material is primarily the favorable combination of high hardness and strength, at the same time high ductility. Thus, a high resistance to abrasive and impact loads is to be expected. Furthermore, this material offers the opportunity to become tungsten regardless of the strategic material and to reduce costs while at the same time reducing manufacturing costs.

The roller according to the invention for a roller press has at least one previously described hard body as a grid armor.

In a preferred embodiment, the roll for the roller press has side wear protection elements which are also made from a high strength iron based alloy (IFW). Side wear protection elements are elements of the armor in the region of the transition from the lateral surface to the end face of the roller. Also, it may be advantageous to make the mold so that it allows a mounting structure such. Welding or thread, which are hardly feasible on a hard body to secure them securely to the roll edges.

The method according to the invention relates to the primary shaping of the wear-resistant hard bodies. The prototyping of the wear-resistant hard body takes place in a closed shell or sleeve as a casting mold. For this purpose, it is placed in a preferably cooled casting housing and then filled with the molten alloy. The shell preferably has a circular cylindrical cross-section with a hemispherical end. Further preferably, the Gießeinhausung the mold is divided, which advantageously facilitates the removal of the workpiece.

Further preferably, the outer side of the casting shell, that is to say the outer diameter of a circular cross-sectional shape, corresponds to the fit of the wear-resistant hard bodies in the bandage of the roll. Advantageously, as a result of the material properties very expensive reworking of the wear-resistant hard body after the prototypes can be largely dispensed with.

Figur 1

einen erfindungsgemäßen Hartkörper mit Hülle,

Figur 2

einen erfindungsgemäßen Hartkörper mit Hülle und Verjüngung,

Figur 3

einen erfindungsgemäßen Hartkörper mit Hülle und Ringfeder, und

Figur 4

einen erfindungsgemäßen Hartkörper mit Hülle und Stahlkern.

Various embodiments of the invention are explained below with reference to figures. Showing:

FIG. 1

a hard body according to the invention with shell,

FIG. 2

a hard body according to the invention with sheath and rejuvenation,

FIG. 3

a hard body according to the invention with shell and annular spring, and

FIG. 4

a hard body according to the invention with shell and steel core.

FIG. 1 shows a hard body according to the invention 1 of a high strength iron-based alloy, namely FeCrMoVC in a closed on one side, hollow cylindrical shell 2 of eg copper. To produce the hard body 1, the shell 2 is placed in a two-part coolable housing and closed the enclosure. Subsequently, the melt of the alloy FeCrMoVC according to the invention is filled in the casing 2 within the housing 1, 2. Thereafter, a tempering by the hard body 4 is heated in the shell 2 twice in succession for 10 minutes to a temperature of 600 ° C.

FIG. 2 shows a hard body 1 according to the invention with a sheath 3 having a taper. By the taper occurs a positive connection of the hard body 1 in the shell 3, whereby falling out of the hard body from the shell 3 can be avoided.

FIG. 3 also shows a hard body 1 according to the invention with a shell 4 comprising a circumferential annular groove in which an annular spring 5 is arranged. By the annular spring 5, a release of the shell 4 can be prevented from the bandage of the role. To remove a hard body 1 with a shell 4 with annular spring 5, a tab is welded to the shell 4 and the hard body 1 is pulled out of this tab by means of a sliding hammer.

FIG. 4 shows a hard body 1 with an inner core 6 made of steel. This core 6 allows a simple expansion, by an aid can be welded to the core 6, with which the hard body 1 together with the shell 7 from the bandage of the role is easily pulled out.

LIST OF REFERENCE NUMBERS

1

hard body

2

shell

3

Case with rejuvenation

4

Case with circumferential groove

5

Ringfeder

6

core

7

open on both sides

Claims (16)

Hard body (1) as a grid armor of a roll of a roller press, characterized in that the hard body (1) consists at least partially of a high-strength iron-based alloy (IFW) and on the lateral surface of a shell (2) or sleeve made of a different material, in particular steel, Copper or a copper alloy. Hard body (1) as a grid armor of a roll of a roller press according to claim 1, characterized in that
the hard bodies (1) have a circular cylindrical shape, wherein the end of the hard body (1) facing the center of the roller has a conical or rounded shape. Hard body (1) as a grid armor of a roll of a roller press according to claim 2, characterized in that
the shell (2) is a hollow cylinder closed on one side with a circular cross-section and the closed end side is hemispherical in shape. Hard body (1) as a grid armor of a roll of a roller press according to claim 3, characterized in that
the shell (3) has a projection on the inside, so that a positive connection is created between the shell (3) and the hard body (1). Hard body (1) as a grid armor of a roll of a roller press according to one of claims 3 or 4,
characterized in that
the sheath (4) on the outside has a receptacle for an annular spring (5). Hard body (1) as a grid armor of a roll of a roller press according to one of claims 3 to 5,
characterized in that
the sheath (4) has a recess on its closed end face. Hard body (1) as a grid armor of a roll of a roller press according to one of claims 3 to 6,
characterized in that
the hard body (1) axially centrally has a core of a weldable material. Hard body (1) as a grid armor of a roll of a roller press according to one of the preceding claims,
characterized in that
the sheath (2) or sleeve on the outside has a profiling. Hard body (1) as a grid armor of a roll of a roller press according to one of the preceding claims,
characterized in that
is the high strength iron alloy FeCrMoVC. Roller for a roller press comprising at least one hard body (1) according to one of the preceding claims. Roller for a roller press according to claim 10,
characterized in that
the wear-resistant hard body (1) are glued into holes in the bandage of the role with fits. Roller for a roller press according to claim 10,
characterized in that
the wear-resistant hard body (1) are pressed into holes in the drum bandage. Roller for a roller press according to one of claims 10 to 12,
characterized in that
the role side wear protection elements designed as a hard body (1) made of a high-strength iron alloy (IFW) has. Method for producing a wear-resistant hard body (1) according to one of claims 2 to 9, characterized in that
for casting the hard bodies (1) a casing or sleeve is introduced into a divided casting housing into which the alloy melt is filled. Method for producing a wear-resistant hard body (1) according to claim 14, characterized in that
the casting housing is liquid cooled. Use of a high-strength iron-base alloy (IFW) for producing hard bodies (1) or side wear protection elements for the role of a roller press.

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