DE102008015845B3 - Bimetallic strip for the production of saw blades, saw bands or doctor blades - Google Patents

Abstract

A bimetallic strip 1 comprising a portion of a carrier tape material 10 and a portion of a cutting material 8 is manufactured by a method comprising the steps of: inserting intermediate sheets 5 of the cutting material 8 into a mold 3, pouring a molten metal 6 of the carrier tape material 10 into the Casting mold 3, wherein the intermediate plates 5 only partially melt, and when solidifying metallurgical connection with the cast-in carrier strip material 10 and form a cast block, removing the ingot 12 from the mold 3, rolling the ingot 12 into a composite band 14, wherein the composite band 14 alternately comprises portions of carrier tape material 10 and portions of cutting material 8 and parts of the composite tape 14 through the sections of cutting material 8, wherein a plurality of bimetallic bands 1 arise. Furthermore, the invention comprises the use of such a bimetallic strip for the production of saw blades, saw bands or doctor blades.

Description

1. Field of the invention

The The present invention relates to a bimetallic strip for manufacturing of saw blades, saw bands or Doctor blades and the use of the bimetallic strip for the production the saw blades, saw bands or String doctoring.

2. Background of the invention

to Production of saw blades or Saw bands with hard and wear-resistant Tooth tip areas become a composite steel sheet in specific applications or composite steel strip used. In very special applications are also used for the production of doctor blades composite steel belts a hard and wear-resistant Edge used as squeegee area. At the edge of a carrier tape made of tough, elastic steel is for this purpose a strip of a cutting or squeegee welded or soldered. Since this composite steel sheet or composite steel strip of at least it is made up of two different materials, it will be below referred to as bimetallic strip.

to Production of a saw blade or -bandes is from the above-mentioned bimetallic strip a tooth profile or a tooth contour corresponding to the later saw blade or band milled or ground out. The resulting teeth include Tip areas consisting of cutting material, for example HSS steel, taking the rest of the saw blade from the tough elastic Steel of the carrier tape consists. Due to the use of HSS steel or other cutting materials have the later tooth tip areas of made of saw blades or Saw bands or the edges of the doctor blades have a high wear resistance on what a high life of these products.

The above-described method of manufacturing saw blades, saw bands or doctor blades due to the separate production of the cutting area and the soldering or Welding the same technically complex and costly.

The publication DE 23 18 471 A discloses a method and apparatus for making saw blades in which a composite saw blade material is made by casting a melt having a composition corresponding to a portion of the saw blade into a billet having a composition corresponding to the other portion of the billet. This bimetallic bar is then rolled out into a strip which is heat treated and into which teeth are cut in one edge.

The The present invention therefore has the technical task of to provide a bimetallic strip for the manufacture of saw blades, saw bands or doctor blades, the easier and cheaper can be made. In addition, the bimetallic band should be the same consistently high quality. After all should the bimetallic strip compared with the prior art lower Require labor and logistics costs with shorter set-up times and flexible with different cutting / squeegee material and material widths be produced.

3. Summary of the invention

These Technical objects of the present invention are the subject matter the independent one claims 1 and 12 solved. Further embodiments of the invention are the dependent claims Find.

• a. Einlegen von Zwischenblechen aus dem Schneidmaterial in eine Gießform;
• b. Eingießen einer Metallschmelze aus dem Trägerbandmaterial in die Gießform, wobei die Zwischenbleche lediglich teilweise aufschmelzen, bei der Erstarrung eine metallurgische Verbindung mit dem eingegossenen Trägerbandmaterial eingehen und einen Gussblock bilden;
• c. Entnehmen des Gussblockes aus der Gießform;
• d. Walzen des Gussblockes zu einem Verbundband, wobei das Verbundband abwechselnd Abschnitte aus Trägerbandmaterial und Abschnitte aus Schneidmaterial aufweist; und
• e. Teilen des Verbundbandes durch die Abschnitte aus Schneidmaterial, wobei mehrere Bimetallbänder entstehen.

In particular, the above objects are achieved by a bimetallic strip having a portion of a carrier tape material and a portion of a cutting material. The bimetallic strip according to the invention is produced by a process comprising the following steps:

• a. Inserting intermediate plates of the cutting material into a casting mold;
• b. Pouring a molten metal from the carrier tape material into the mold, wherein the intermediate sheets only partially melt, undergo a metallurgical bond with the cast-in carrier tape material during solidification and form a cast block;
• c. Removing the ingot from the mold;
• d. Rolling the ingot to a composite strip, wherein the composite strip alternately comprises sections of carrier strip material and sections of cutting material; and
• e. Dividing the composite band by the sections of cutting material, with multiple bimetallic bands arise.

Thus, a bimetallic strip is provided, from which a very large amount of bimetallic bands can be produced at the same time in only one pass through a casting and rolling plant. One of the main advantages of the method is that the elaborate process step of welding the cutting material to the carrier tape material is eliminated. The inserted intermediate plates of the cutting material almost automatically weld to the carrier tape material when it is poured. This leads to significantly shorter set-up and transport times and significantly less input material is consumed. The rolling process is passed through only by a component that at least already contains two different types of steel. After rolling, the resulting composite tape only needs to be separated into the desired bimetallic bands.

One Another advantage of the method is that the cutting material no longer used in the form of flat wire. Instead can be used simple sheet of the cutting material, what only one third of the acquisition costs.

The Production can be fully automatic, without manual activities to need and is therefore very inexpensive. There are bimetallic bands with provided a consistently high quality because manual operations omitted. Furthermore, for the production of bimetallic bands almost no waste material generated.

In addition is the connection of cutting material and carrier tape material particularly high resilient, since they are already at the beginning of the manufacturing process to water of the carrier tape material arises. The further rolling processes from the ingot to the composite band and finally to the bimetal band this existing connection no longer.

In a preferred embodiment the pouring happens the molten metal in the mold rising, that is from below, and thus less turbulent than when pouring above. As a result, the partial melting of the intermediate plates takes place in a controlled manner, reducing the later thickness of the cutting material can be defined more precisely in the ingot.

The Temperature of the poured molten metal is preferably below or in the region of the melting temperature of the cutting material, wherein the dimensioning of the intermediate plate depending on the used Materials and the casting temperature a complete one Melting of the cutting material is excluded.

In a further preferred embodiment melts 0.1-50%, preferably 0.2-30%, more preferably 0.3-15% and more preferably 0.5-5% of respective thickness of the intermediate plates during casting. The molten metal so solidifies in the mold before the intermediate plates completely melt. required is a large-scale, but local melting, resulting in a metallurgical compound, this means to a welding of leads to both types of steel.

in the In general, the melting should be sufficiently large, a good connection of the intermediate plates with the carrier tape material to ensure, however, it should be as low as possible so that the carrier tape material not significantly alloyed by the molten cutting material becomes. Too high an alloy of the carrier tape material would be the Change of bending / fatigue strength of the carrier tape, causing a breakout of teeth a saw could lead.

Prefers can the flow conditions controlled in the molten pool by electromagnetic fields, to the turbulence in the rising molten metal in the mold yet continue to calm down and control the melting of the intermediate plates.

The Intermediate plates preferably have a biconvex cross-section and / or in the casting direction one decreasing thickness. Through these measures, the intermediate plates can those in the mold adapted to different speeds of solidification become. Usually freezes a cast block last in the middle. Due to the geometry of the inserted Intermediate plates become possible Shape and dimension changes during the subsequent solidification, shrinkage, forming and possible further heat treatments balanced.

The Intermediate plates can, depending on the desired Dimension of the bimetallic strip, evenly or non-uniformly be spaced and / or the same or a different thickness exhibit. The distance between the intermediate plates and their thickness determine the later ones Widths of the cutting and carrier tape material sections the bimetallic bands out.

Farther are the inserted intermediate plates preferably by spacers, Clamps and / or centerings held from all sides during the pouring Completely melt. The spacers, clamps and / or centerings prevent shifting or tilting of the intermediate plates when later pour in the molten metal. As a material for the spacers are preferably used low-melting metallic materials. This one while the casting process ideally complete they do not cause any problems with subsequent processing.

In a preferred embodiment The rolling of the ingot comprises hot and / or cold rolling. By rolling, the ingot is formed into a bimetallic strip.

The method for producing the bimetallic strip may preferably further comprise heat treatment steps. The heat treatment serves to improve the material properties or to facilitate the processability.

Prefers For example, the method of making the bimetallic strip includes straightening and / or winding the bimetallic bands. Judging leads to straight and precise Bimetallbändern, the for the transport and storage are wound up into a so-called coil can.

Farther The technical problem of the invention is the use of a Bimetal bands described above for the production of saw blades, saw bands or Scraper blades solved. The Use of bimetallic bands in the production of saw blades, saw bands or Streichrakeln leads to significantly cheaper Saw blades, saw bands or Streichrakel, since the produc- tion of the bimetallic bands significantly cheaper is, than the usual Production of such bimetallic bands

4. Brief description of the accompanying drawings

The The present invention will be described with reference to the accompanying drawings Drawings illustrated embodiments described. It shows:

1 a cross-sectional view of a preferred embodiment of a mold for rising casting, are placed in the intermediate plates;

2 a cross-sectional view of an embodiment of a cast block of two, alternating steel grades;

3 a cross-sectional view of a preferred embodiment of a composite tape;

4 a cross-sectional view of a preferred bimetallic strip after separation; and

5 a preferred cross-sectional shape of an intermediate plate in the section AA 1 ,

5. Detailed description of the preferred embodiments

in the The following are preferred embodiments of the present invention with reference to the figures in detail explained.

1 shows a mold 3 , in the intermediate sheets 5 are inserted from cutting material. At the intermediate plates 5 It is preferred to metallic blank ground, scale-free sheets to avoid non-metallic voids between the different metal types. To avoid oxide inclusions, the casting steps or the entire production can be carried out under protective gas or in vacuo.

The intermediate plates 5 are preferably between 8-15 mm thick and are arranged at the desired distances from each other. The intermediate plates are preferred 5 arranged at a distance which corresponds approximately to twice the width of the bimetallic strip to be produced later.

The intermediate plates 5 can have a biconvex cross section, as in 5 is shown by way of example. Here, the thickness D decreases in cross section from the inside to the outside, to the prevailing during casting slower solidification of the melt in the middle of the mold 3 counteract. The biconvex cross section allows the intermediate plates 5 melting in the middle more than at the edge, but in the solidified ingot 12 the remaining cutting material 8th everywhere is the same thickness.

For the same reason, the intermediate plates 5 in the casting direction G have a decreasing thickness D to those in the mold 3 adapted to different running solidification speeds. They may be evenly or non-uniformly spaced, and / or have the same or different thickness. The intermediate plates 5 Cutting material may also have kinks, steps or bulges.

To the inserted intermediate plates 5 when pouring in the mold 3 They are fixed by spacers, clamps and / or centerings 16 held in place and by means of a hanger 18 in the mold 3 hanged. The chaperon 16 are designed so that they melt completely in the course of the casting, as soon as the melt has calmed after casting.

The infusion of molten metal 6 in the mold 3 is preferably rising, that is, by a feed system from below, as by the arrows 6 in 1 indicated. This increases the level of molten metal 6 in the mold 3 less turbulent than pouring from above. Pouring the molten metal 6 takes place at a defined temperature and rate and takes about 1 minute.

The flow conditions in the molten pool can be influenced by electromagnetic fields to z. As the turbulence in the rising molten metal 6 in the mold 3 to calm down even further.

The temperature of the poured molten metal 6 from the carrier tape material 10 lies un ter or in the melting temperature of the cutting material 8th the intermediate plates 5 , Therefore, the molten metal solidifies 6 in the mold 3 before the intermediate plates 5 completely melted. It is crucial that the thickness D of the intermediate plates 5 depending on the materials used for cutting and carrier tape material and depending on the casting temperature and other casting influences is chosen so that after the solidification of the carrier tape material 10 a defined thickness of the intermediate sheets of cutting material 8th in the cast block 12 remains.

What is desired is only a large-scale, but local melting, which leads to a metallurgical connection, that is, to a welding of the two types of metal. The intermediate plates 5 melt to 0.1-50%, preferably 0.2-30%, more preferably 0.3-15% and most preferably 0.5-5% of their thickness D during casting. A complete melting, which would lead to a mixture of the two metals by diffusion to be prevented. The intermediate plates 5 Therefore, not only serve to calm the melt pool but form a crucial component of the later bimetallic strip, namely the desired section of cutting material.

The cast block 12 then gets out of the mold 3 taken. This removal can be achieved by a corresponding pyramidal or conical shape of the mold 3 and be facilitated by appropriate coatings. This cast or composite block 12 can weigh between 2.5 to 5 t.

The cast block 12 as he is in 2 is shown by way of example in cross-section, is transformed in the course of the rolling steps to a so-called. Slab. This forming may include forging and / or hot working or hot rolling. The slab is between 9 and 15 m long, 300 to 340 mm wide and 80 to 100 mm thick.

By rolling the slab, the cutting material 8th lose its desired shape. It may possibly z. B. a biconvex, that is to assume a lens-like shape. Such effects can be counteracted by the intermediate plates 5 be formed in the corresponding negative mold.

The slab passes through a hot rolling mill around a composite strip 14 to manufacture in 3 is shown schematically in cross section. The temperatures in the hot rolling mill are between 1100 and 1150 ° C. The workpiece is rolled down to a thickness of 2.5 to 4.5 mm. The width remains approximately constant, this is the composite band 14 longer and longer. By rolling (hot and / or cold) additionally isotropic or anisotropic material properties can be introduced into the bimetallic strip to be produced.

The composite tape 15 reached after cold rolling the final dimensions of z. B. 0.65 mm, 0.95 mm, 1.13 mm or 1.65 mm.

For producing the desired bimetallic bands 1 becomes the composite tape 14 then in the area of the cutting material 8th shared, as in 3 through the dividing lines 20 indicated. This is the composite tape 14 split or slotted.

The area of the cutting material 8th should usually be shared in the middle. Due to the rolling process, however, slight changes in position of the cutting material can occur 8th in composite tape 14 result. If the transitions between the two metal types are invisible to the eye, the two metal types can be automatically detected by electrical conductivity measurements. The desired cutting line 20 (eg the center of the cutting material 8th ) can then z. B. be laser marked, and thus allows a precise sharing of the composite tape 3 to individual bimetallic bands 1 as they are in 4 are shown.

After that can Steps of straightening and winding the bimetallic bands follow. Furthermore you can mechanical machining of bimetallic bands, another heat treatment (eg homogenization annealing) be downstream.

The bimetallic bands can then be used to make saw blades, saw bands or doctor blades. For saw blades or saw blades is at the edge with the cutting material 8th a sawtooth contour in the bimetallic strip 1 introduced so that the tooth tip areas by cutting material 8th be formed. The bimetallic strip needs to be produced in order to produce doctor blades 1 only suitable to be ground.

The cutting material 8th can consist of rolled HSS sheets. Suitable materials for the cutting material 8th are the high speed steels with the numbers 1.3207, 1.3247, 1.3299, 1.3243 and 1.3243, with the speed steels with the numbers 1.3207 and 1.3247 preferred cutting materials 8th for saw blades, saw blades and, depending on the application, also for doctor blade edges.

For the carrier tape materials 10 the following steels are possible:
1.2791 (40CrMoV4-10)
1.2323 (48CrMoV6-7)
1.8159 (51 CrV4)

Are preferred as a carrier tape material 10 the following steels used:
1.2390 (32CrMoV16, 32CrMoV12)
1.2394 (30CrMoV16)

Particularly preferred combinations of cutting material 8th and carrier tape material 10 are the combinations of steels 1.3247 / 1.2390, 1.3247 / 1.2394, 1.3207 / 1.2390 and 1.3207 / 1.2394.

1

bimetal strip

3

mold

5

intermediate plate

6

molten metal

8th

cutting material

10

Carrier tape material

12

Ingot

14

composite tape

16

Spacer Clamps, centerings

18

hanger

20

dividing line

G

casting

D

thickness the intermediate plates

Claims (12)

Bimetallic strip ( 1 ) comprising a portion of a carrier tape material ( 10 ) and a section of a cutting material ( 8th ) prepared by a method comprising the steps of: a. Inserting several intermediate plates ( 5 ) from the cutting material ( 8th ) into a casting mold ( 3 ); b. Pouring a molten metal ( 6 ) from the carrier tape material ( 10 ) in the mold ( 3 ), wherein the intermediate plates ( 5 ) melt only partially, upon solidification a metallurgical bond with the cast-in carrier tape material ( 10 ) and a cast block ( 12 ) form; c. Removing the cast block ( 12 ) from the mold ( 3 ); d. Rolling of the cast block ( 12 ) to a composite tape ( 14 ), wherein the composite tape ( 14 ) alternately several sections of carrier tape material ( 10 ) and several sections of cutting material ( 8th ) having; and e. Dividing the composite strip ( 14 ) through the sections of cutting material ( 8th ), wherein several bimetallic bands ( 1 ) arise. Bimetallic strip according to claim 1, wherein the pouring of the molten metal ( 6 ) in the mold ( 3 ) rising happens. Bimetallic strip according to one of claims 1 or 2, wherein the temperature of the cast-in molten metal ( 6 ) below or in the region of the melting temperature of the cutting material ( 8th ) lies. Bimetallic strip according to one of claims 1-3, wherein during casting 0.1-50%, preferably 0.2-30%, more preferably 0.3-15% and particularly preferably 0.5-5% of the respective thickness of the intermediate sheets ( 5 ) melts. Bimetallic strip according to one of claims 1-4, wherein the intermediate plates ( 5 ) have a biconvex cross section and / or have a decreasing thickness (D) in the casting direction (G). Bimetallic strip according to a of claims 1-5, wherein the flow conditions be controlled in the molten pool by electromagnetic fields. Bimetallic strip according to one of claims 1-6, wherein the inserted intermediate plates ( 5 ) are uniformly or non-uniformly spaced from each other and / or have the same or a different thickness (D). Bimetallic strip according to one of claims 1-7, wherein the inserted intermediate plates ( 5 ) by spacers, clamps and / or centerings ( 16 ), which melt completely during pouring. Bimetallic strip according to any one of claims 1-8, wherein the rolling of the ingot ( 12 ) comprises a hot and / or a cold rolling. Bimetallic strip according to a of claims 1-9, wherein the process continues heat treatment steps includes. Bimetallic strip according to any one of claims 1-10, wherein the method further comprises straightening and / or winding the bimetallic bands ( 1 ). Use of a bimetallic strip ( 1 ) according to any one of claims 1-11, for the manufacture of saw blades, saw bands or doctor blades.