High-speed steel cutting tools and their injection molding preparation methods and applications

Abstract

This invention belongs to the field of high-speed steel, specifically relating to a method for preparing high-speed steel cutting blades by injection molding. The method involves preparing raw materials comprising Ni, C, Cr, Mo, W, V, Co, Nb, a modifier, and Fe; ball milling the mixed raw materials to obtain powder; pre-modifying the powder with a titanate coupling agent to obtain modified powder; mixing the modified powder with a polymer, followed by injection molding, sintering, heat treatment, and polishing to obtain the high-speed steel cutting blades; the chemical formula of the modifier is: (Hf x Zr y Ta z Ti m Me n B2; the Me comprises at least one of V, W, and Mo; the x, y, z, m, and n are each 0.1 to 0.3, and x+y+z+m+n=1. This invention can improve the performance of the prepared high-speed steel cutting tools, especially its nickel-free welding performance.

Description

Technical Field

[0001] This invention relates to the field of high-speed steel, and more specifically to the field of high-speed steel cutting tool preparation. Background Technology

[0002] Conventional cutting inserts are mainly used in bimetal band saws and welded composite band saws, and are primarily made of cast or forged high-speed steel, powder high-speed steel, or WC-Co cemented carbide. However, conventional high-speed steel lacks sufficient wear resistance, while cemented carbide lacks sufficient toughness and is prone to chipping. Therefore, there is a lack of cutting insert materials on the market that offer performance between high-speed steel and cemented carbide, providing both wear resistance and chipping resistance.

[0003] In addition, conventional cemented carbide is prepared by molding-sintering, while high-speed steel is prepared by rolling, forging or rotary forging into wire, and then wire cutting.

[0004] For example, Chinese patent document CN117300117A discloses a method for preparing high-speed steel wire using rotary forging, followed by cutting and polishing to produce band saw blades. However, the material prepared by this method generally has a hardness below 68 HRC, and the blades must be nickel-plated, limiting its use to low- to mid-range products. Chinese patent document CN114657325A discloses a wear-resistant high-speed steel and its preparation method. This high-speed steel is produced through an in-situ method to generate boride-reinforced high-speed steel; however, the method used is casting, which makes it difficult to efficiently produce small-sized wear-resistant parts with high strength and high hardness.

[0005] In summary, there is relatively little research on high-speed steel cutting tools. The few existing preparation methods still suffer from problems such as low molding efficiency and difficulty in preparing high-speed steel cutting tools with high resistance welding strength without nickel plating. Furthermore, there is no technology in the industry to prepare high-speed steel cutting tools using powder injection molding. Summary of the Invention

[0006] To fill the technological gap in the injection molding preparation of high-speed steel cutting tools, the primary objective of this invention is to develop an injection molding preparation method for high-speed steel cutting tools, aiming to prepare high-speed steel cutting tools with excellent properties such as high resistance welding strength without nickel plating based on an improved injection molding method.

[0007] The second objective of this invention is to provide high-speed steel cutting blades prepared by the aforementioned method and their applications.

[0008] Although injection molding is a mature method for preparing other alloys, the preparation of high-speed steel cutting blades by injection molding is still a gap in the industry. The main reasons are: (1) Traditional high-speed steel injection molded parts are mostly made of atomized powder as raw material and sintered using an ultra-solid-liquid phase sintering process. The microstructure is coarse, making it difficult to produce cutting tools with high life and high precision, and even more difficult to meet the requirements of sawing blades; (2) When ball milled powder is used for injection molding, the ball milled powder is relatively fine, and the amount of traditional molding agent added is large, making it difficult to mix evenly. It is also easy for the powder to spontaneously combust during heating and mixing. Subsequent sintering is also difficult to achieve full densification of solid phase sintering. Therefore, the microstructure and properties cannot meet the application requirements of cutting blades. In view of this problem, the present invention provides the following improvement scheme:

[0009] A method for preparing high-speed steel scissor pellets by injection molding involves preparing a mixed raw material comprising a high-speed steel precursor and a modifier, wherein the high-speed steel precursor is a raw material comprising Ni, C, Cr, Mo, W, V, Co, Nb, and Fe; and ball milling the mixed raw material to obtain powder.

[0010] The powder is pre-modified with a titanate coupling agent to obtain modified powder; the modified powder and polymer are mixed, and then injection molded, sintered, heat-treated and polished to obtain the high-speed steel blades.

[0011] The chemical formula of the modifier is: (Hf x Zr y Ta z Ti m Me n B2; the Me includes at least one of V, W, and Mo; the x, y, z, m, and n are each 0.1 to 0.3, and x+y+z+m+n=1.

[0012] To address the challenges in injection molding of high-speed steel cutting tools, this invention innovatively incorporates a certain amount of the aforementioned modifier into the raw materials. Based on the combined control of the modifier components, and further combined with the pre-modification of titanate coupling agents, the problems in injection molding of high-speed steel cutting tools can be solved, and the performance of the prepared high-speed steel cutting tools can be improved, especially its nickel-free welding performance.

[0013] In this invention, the high-speed steel precursor material can be a single element or an alloy of various elements.

[0014] In the precursor materials for high-speed steel, the weight percentage of Ni is 2.5-6.5 parts.

[0015] The weight of C is 3.2-4.0 parts;

[0016] The weight parts of Cr are 3.0-6.0 parts;

[0017] The weight parts of Mo are 4.5-9.5 parts;

[0018] The weight parts of W are 6.0-13.0 parts;

[0019] The weight parts of V are 6.0-12.0 parts;

[0020] The weight parts of Co are 9.0-13.0 parts;

[0021] The weight parts of Nb are 1.0-2.0 parts;

[0022] The weight of Fe is 45 to 65 parts.

[0023] Preferably, the high-speed steel precursor raw material contains the following components in weight percentage: C: 3.2%-4.0%, Cr: 3.0%-6.0%, Ni: 2.5%-6.5%, Mo: 4.5%-9.5%, W: 6.0%-13.0%, V: 6.0%-12.0%, Co: 9.0%-13.0%, Nb: 1.0%-2.0%, with the balance being Fe; more preferably, C: 3.5%-4.0%, Cr: 4.0%-4.5%, Ni: 4.5%-5%, Mo: 7%-9%, W: 10%-12.0%, V: 8.0%-9.0%, Co: 11%-12.0%, Nb: 1.0%-1.5%, with the balance being Fe.

[0024] This invention innovatively incorporates the components of the aforementioned chemical formula into processes such as ball milling and subsequent sintering. This allows for integration with other operating parameters, which helps optimize the performance of high-speed steel cutting tools prepared by injection molding, particularly improving their nickel-free welding performance.

[0025] In this invention, the modifiers x, y, z, m, and n are each 0.2 ± 0.05; preferably 0.2.

[0026] Preferably, the modifier is 10-35% of the weight of the high-speed steel precursor raw material; more preferably, it is 20.0%-30.0%.

[0027] Preferably, the particle size of each component in the mixed raw materials is 2.0-15.0 μm.

[0028] In this invention, the ball milling is a wet ball milling process.

[0029] Preferably, a forming agent is added during the ball milling stage.

[0030] Preferably, the forming agent is 3 to 6% of the weight of the high-speed steel precursor raw material.

[0031] Preferably, the milling medium is alcohol.

[0032] Preferably, the abrasive used in the ball mill is a cemented carbide ball.

[0033] Preferably, the ball milling time is 10~48h, and more preferably 15~25h.

[0034] Preferably, the particle size of the ball-milled powder is ≤15μm.

[0035] In this invention, the powder and titanate coupling agent can be pre-modified, which facilitates combination with other processes to synergistically optimize the performance of high-speed steel cutting tools prepared by injection molding, meet sawing performance requirements, and in particular improve their nickel-free welding performance.

[0036] In this invention, during the modification process, the powder is placed in a solution containing a titanate coupling agent for modification treatment; the titanate coupling agent is 1 to 3% of the weight of the high-speed steel precursor raw material.

[0037] Preferably, the temperature during the modification stage is 45~55℃.

[0038] Preferably, the modification time is more than 1 hour, and more preferably 1 to 4 hours.

[0039] In this invention, the polymer includes an acrylic resin.

[0040] Preferably, the polymer is 10-20% of the weight of the high-speed steel precursor raw material, and more preferably 13-16%.

[0041] Preferably, the mixing temperature is 160~190℃.

[0042] Preferably, the temperature during the injection molding stage is 160~190℃.

[0043] Preferably, the injection pressure during the injection molding stage is 60~100MPa.

[0044] In this invention, the sintering process includes hot degreasing and gas pressure sintering.

[0045] The thermal degreasing process involves a temperature T1 of 400–600℃ and a duration of at least 5 hours, which can be extended to 4–10 hours. The thermal degreasing process may include multiple stages of gradient heating, with a temperature difference of 40–120℃ between each gradient. The processing time for a single stage can be 1–5 hours.

[0046] The temperature for gas pressure sintering is 1100~1300℃, the pressure is 2.0-5.0MPa, and the time for gas pressure sintering is 2~5h.

[0047] In this invention, the heat treatment process includes quenching, deep cooling and tempering; wherein, the quenching process is carried out under vacuum, the temperature is 1180~1210℃, the holding time is not less than 30min, and the quenching medium is inert gas or oil.

[0048] The cryogenic temperature is -80~-150℃, and the holding time is no less than 8 hours;

[0049] The tempering temperature is 580-650℃; the tempering number is 2-6 times, and each tempering is not less than 1.5 hours.

[0050] The present invention also provides a high-speed steel cutting tool prepared by the aforementioned method.

[0051] The preparation method described in this invention can endow the prepared material with special physicochemical properties, and the material with the aforementioned properties obtained by the preparation method can unexpectedly and significantly improve the performance of the prepared high-speed steel cutting blade.

[0052] This invention also provides an application of the high-speed steel cutting inserts prepared by the aforementioned method, for the preparation of band saws and / or welded composite bands. Compared with high-speed steel cutting inserts obtained by traditional casting and rolling methods and cutting, the cutting inserts prepared by this invention can directly achieve high-strength resistance welding without nickel plating.

[0053] Beneficial effects:

[0054] (1) This invention is the first to prepare high-performance powder metallurgy high-speed steel cutting tools based on injection molding process, filling a gap in the industry.

[0055] (2) In view of the problems faced in the injection molding preparation of high-speed steel blades, the present invention innovatively uses a modifier to participate in the entire preparation process. In addition, with the combined control of processes such as polymer modification, it is possible to successfully achieve the injection molding preparation of high-performance high-speed steel blades. Moreover, it can also optimize the microstructure of the material and improve its performance, especially its nickel-free welding performance. Attached Figure Description

[0056] Figure 1 This is a microstructure diagram of the sintered state in Example 1;

[0057] Figure 2 These are images of the polished cutting tools from Example 1;

[0058] Figure 3 This is a macroscopic microstructure diagram of the weld in Example 1. Detailed Implementation

[0059] The purpose of this invention is to overcome the shortcomings of the prior art and provide a powdered high-speed steel-based composite material and a method for preparing cutting particles.

[0060] In the following examples, the content of raw materials is expressed as a weight percentage.

[0061] In this invention, the amounts of the molding agent and polymer are based on the weight of the high-speed steel precursor raw material.

[0062] Example 1

[0063] The high-speed steel precursor raw material composition is C: 3.5%, Cr: 4.0%, Ni: 5.0%, Mo: 7.0%, W: 10.0%, V: 8.0%, Co: 12.0%, Nb: 1.0%, with the balance being Fe. The high-speed steel precursor raw material and modifier ((Hf)) are then mixed. 0.2 Zr 0.2 Ta 0.2 Ti 0.2 Me 0.2 Mix (B2, Me=V); the modifier is 30% of the weight of the high-speed steel precursor raw material) to obtain a mixed raw material. Add 5% of the forming agent (paraffin wax) and place it in a planetary ball mill. The ball milling solvent is alcohol, and the ball milling balls are cemented carbide balls. Wet mill for 16 hours. Keep the ball-milled powder at 70℃ for 46 hours. Put the dried powder into an alcohol solution of titanate coupling agent (titanate coupling agent is 1% of the weight of the high-speed steel precursor raw material) at a solution temperature of 45~55℃ and soak for more than 2 hours. Then dry it in a vacuum stirring drying oven at 70℃ to obtain modified powder.

[0064] The modified powder was placed in an internal mixer, and acrylic resin was added. The resin accounted for 15% of the high-speed steel precursor raw material content. The mixing temperature was 180℃ to obtain the feedstock. After heating the feedstock to 180℃, it was injected into the mold at an injection pressure of 75MPa to obtain an injection-molded preform with a density of 4.8g / cm3.

[0065] The injection molding process involves degreasing and sintering, with hot degreasing at 450℃ for 2 hours, followed by holding at 500℃ for 4 hours and then holding at 600℃ for 2 hours. Subsequently, gas pressure sintering is performed, with a sintering gas pressure of 4.5 MPa and a gas pressure sintering temperature of 1300℃ for 4 hours.

[0066] The sintered blank of the cutting blade was subjected to vacuum quenching, deep cryogenic treatment and three tempering processes. The vacuum quenching temperature was 1200℃ and the holding time was 45 min. The quenching medium was oil. The deep cryogenic temperature was -120℃ and the holding time was 8 h. The tempering temperature was 580℃ and the tempering time was 1.5 h each time to obtain the cutting blade. The hardness of the obtained cutting blade was 73.5 HRC. Figure 1 This is a microstructure diagram of the sintered state in Example 1; Figure 2 These are images of the polished cutting tools from Example 1; Figure 3 This is a macroscopic microstructure diagram of the weld in Example 1, without nickel plating, with an average weld strength of 1150 MPa.

[0067] Example 2

[0068] The high-speed steel precursor raw material composition is C: 4.0%, Cr: 4.5%, Ni: 4.5%, Mo: 9.0%, W: 12.0%, V: 9.0%, Co: 11.0%, Nb: 1.5%, with the balance being Fe. The high-speed steel precursor raw material and modifier ((Hf)) are then added... 0.2 Zr 0.2 Ta 0.2 Ti 0.2 Me 0.2 Mix (B2, Me=W) and (modifier is 20% of the weight of high-speed steel precursor raw material) to obtain a mixed raw material. Add 4% of the weight of high-speed steel precursor raw material forming agent (paraffin wax) and place it in a planetary ball mill. The ball milling solvent is alcohol, and the ball milling balls are cemented carbide balls. Wet mill for 20 hours. After ball milling, the powder is dried at 70°C for 46 hours. The dried powder is placed in an alcohol solution of titanate coupling agent (titanate coupling agent is 1.5% of the weight of high-speed steel precursor raw material) at a solution temperature of 45~55°C and soaked for more than 2 hours. Then, it is dried in a vacuum stirring drying oven at 70°C.

[0069] The modified powder was placed in an internal mixer, and acrylic resin was added. The resin accounted for 13% of the high-speed steel precursor material content. The mixing temperature was 180℃ to obtain the feedstock. After heating the feedstock to 180℃, it was injected into the mold at an injection pressure of 75MPa to obtain an injection-molded preform with a density of 4.6g / cm3.

[0070] The injection molding process involves degreasing and sintering, with hot degreasing at 450℃ for 2 hours, followed by holding at 500℃ for 4 hours and then holding at 600℃ for 2 hours. Subsequently, gas pressure sintering is performed at a sintering gas pressure of 3.5 MPa and a gas pressure sintering temperature of 1200℃ for 3 hours.

[0071] The sintered blade blanks underwent vacuum quenching, deep cryogenic treatment, and three tempering processes. Vacuum quenching was performed at 1180℃ for 50 minutes using oil as the quenching medium. Deep cryogenic treatment was performed at -120℃ for 10 hours. Tempering was performed at 620℃ for 2 hours each time. After heat treatment, the blade blanks achieved a hardness of 74.0 HRC. They were not nickel-plated, and the average weld strength was 1130 MPa.

[0072] Example 3

[0073] Step 1:

[0074] The high-speed steel precursor raw material composition is C: 3.5%, Cr: 4.0%, Ni: 5.0%, Mo: 7.0%, W: 10.0%, V: 8.0%, Co: 12.0%, Nb: 1.0%, with the balance being Fe. The high-speed steel precursor raw material and modifier (Hf) are then added... 0.2 Zr 0.2 Ta 0.2 Ti0.2 Me 0.2 Mix (B2, Me=Mo); the modifier is 25% of the weight of the high-speed steel precursor raw material) to obtain a mixed raw material. Add 5% of the weight of the high-speed steel precursor raw material forming agent (paraffin wax) and put it into a planetary ball mill. The ball milling solvent is alcohol, and the ball milling balls are cemented carbide balls. Wet mill for 16 hours. The ball-milled powder is then heated at 70°C for 46 hours.

[0075] Step 2:

[0076] The dried powder is placed in an alcoholic solution of titanate coupling agent (1.0% of the weight of the high-speed steel precursor raw material) at a solution temperature of 45~55℃ and soaked for more than 2 hours. Then, it is dried in a vacuum stirring drying oven at 70℃.

[0077] Step 3:

[0078] The modified powder was placed in an internal mixer, and acrylic resin was added. The resin accounted for 15% of the high-speed steel precursor raw material content. The mixing temperature was 180℃ to obtain the feedstock. After heating the feedstock to 180℃, it was injected into the mold at an injection pressure of 75MPa to obtain an injection-molded preform with a density of 4.8g / cm3.

[0079] Step 4:

[0080] The injection molding process involves degreasing and sintering, with hot degreasing at 450℃ for 2 hours, followed by holding at 500℃ for 4 hours and then holding at 600℃ for 2 hours. Subsequently, gas pressure sintering is performed, with a sintering gas pressure of 4.0 MPa and a gas pressure sintering temperature of 1300℃ for 4 hours.

[0081] The sintered blank of the blade is subjected to quenching, deep cooling and three tempering treatments. The vacuum quenching temperature is 1200℃ and the holding time is 45min. The quenching medium is oil. The deep cooling temperature is -120℃ and the holding time is 8h. The tempering temperature is 580℃ and each tempering time is 1.5h to obtain the blade.

[0082] Tests show that the resulting blade has a hardness of 73.2 HRC. Without nickel plating, the average weld strength is 1180 MPa.

[0083] Comparative Example 1

[0084] Compared with Example 3, the only difference is that no modifier was added in step 1, while the other operations and parameters are the same as in Example 1.

[0085] The resulting blade has a hardness of 69.0 HRC. Without nickel plating, the average weld strength is 700 MPa, with a small number of weld cracks observed.

[0086] Comparative Example 2

[0087] Compared with Example 3, the only difference is that in step 1, an equal amount of alumina is used as the modifier, while other operations and parameters are the same as in Example 1.

[0088] The resulting cutting inserts have a hardness of 35-40 HRC. Unplated nickel exhibits welding cracking.

[0089] Comparative Example 3

[0090] Compared with Example 3, the only difference is that step 2 is not performed, but the material from step 1 is used as raw material for step 3 and subsequent steps.

[0091] The results showed that when the feed material was heated to 180°C and injected into the mold at an injection pressure of 75 MPa, the powder spontaneously combusted, and the resin was insufficient to wet the powder, resulting in injection molding failure.

[0092] Comparative Example 4

[0093] Compared with Example 3, the only difference is that in step 2, a silane coupling agent is used instead of the phthalate coupling agent, while other operations and parameters are the same as in Example 1.

[0094] The injection-molded preform has low strength, resulting in injection molding failure.

Claims

1. A method for preparing high-speed steel cutting tools by injection molding, characterized in that, A mixed raw material comprising high-speed steel precursor raw material and modifier is prepared, wherein the high-speed steel precursor raw material comprises Ni, C, Cr, Mo, W, V, Co, Nb and Fe; the mixed raw material is ball-milled to obtain powder. The powder is pre-modified with a titanate coupling agent to obtain modified powder; the modified powder and polymer are mixed, and then injection molded, sintered, heat-treated and polished to obtain the high-speed steel blades. The chemical formula of the modifier is: (Hf x Zr y Ta z Ti m Me n B2; the Me includes at least one of V, W, and Mo; the x, y, z, m, and n are each 0.1 to 0.3, and x+y+z+m+n=1.

2. The method for preparing high-speed steel cutting tools by injection molding as described in claim 1, characterized in that, In the precursor materials for high-speed steel, the weight part of Ni is 2.5 to 6.5 parts; The weight of C is 3.2 to 4.0 parts; The weight parts of Cr are 3.0 to 6.0 parts; The weight parts of Mo are 4.5 to 9.5 parts; The weight parts of W are 6.0 to 13.0 parts; The weight parts of V are 6.0 to 12.0 parts; The weight parts of Co are 9.0~13.0 parts; The weight parts of Nb are 1.0 to 2.0 parts; The weight of Fe is 45 to 65 parts.

3. The method for preparing high-speed steel cutting tools by injection molding as described in claim 2, characterized in that, The high-speed steel precursor raw material contains the following components in weight percentage: C: 3.2%~4.0%, Cr: 3.0%~6.0%, Ni: 2.5%~6.5%, Mo: 4.5%~9.5%, W: 6.0%~13.0%, V: 6.0%~12.0%, Co: 9.0%~13.0%, Nb: 1.0%~2.0%, with the balance being Fe.

4. The method for preparing high-speed steel cutting tools by injection molding as described in claim 1, characterized in that, In the modifier, x, y, z, m, and n are individually 0.2 ± 0.

05.

5. The method for preparing high-speed steel cutting tools by injection molding as described in claim 1, characterized in that, The modifier is 10-35% of the weight of the high-speed steel precursor raw material.

6. The method for preparing high-speed steel cutting tools by injection molding as described in claim 1, characterized in that, The ball milling method is wet ball milling.

7. The method for preparing high-speed steel cutting tools by injection molding as described in claim 6, characterized in that, A forming agent is added during the ball milling stage.

8. The method for preparing high-speed steel cutting tools by injection molding as described in claim 7, characterized in that, The forming agent is 3-6% of the weight of the high-speed steel precursor raw material.

9. The method for preparing high-speed steel cutting tools by injection molding as described in claim 6, characterized in that, The grinding media was alcohol.

10. The method for preparing high-speed steel cutting tools by injection molding as described in claim 1, characterized in that, The abrasive used in ball milling is cemented carbide balls.

11. The method for preparing high-speed steel cutting tools by injection molding as described in claim 1, characterized in that, The ball milling time is 10~48 hours.

12. The method for preparing high-speed steel cutting tools by injection molding as described in claim 1, characterized in that, The particle size of the ball-milled powder is ≤15μm.

13. The method for preparing high-speed steel cutting tools by injection molding as described in claim 1, characterized in that, During the modification process, the powder is placed in a solution containing a titanate coupling agent for modification treatment.

14. The method for preparing high-speed steel cutting tools by injection molding as described in claim 13, characterized in that, The titanate coupling agent is 1-3% of the weight of the high-speed steel precursor raw material.

15. The method for preparing high-speed steel cutting tools by injection molding as described in claim 1, characterized in that, The temperature during the modification stage is 45~55℃.

16. The method for preparing high-speed steel cutting tools by injection molding as described in claim 1, characterized in that, The modification time is more than 1 hour.

17. The method for preparing high-speed steel cutting tools by injection molding as described in claim 1, characterized in that, The polymers include acrylic resins.

18. The method for preparing high-speed steel cutting tools by injection molding as described in claim 1, characterized in that, The polymer is 10-20% of the weight of the high-speed steel precursor raw material.

19. The method for preparing high-speed steel cutting tools by injection molding as described in claim 1, characterized in that, The mixing temperature is 160~190℃.

20. The method for preparing high-speed steel cutting tools by injection molding as described in claim 1, characterized in that, The temperature during the injection molding stage is 160~190℃.

21. The method for preparing high-speed steel cutting tools by injection molding as described in claim 1, characterized in that, The injection pressure during the injection molding stage is 60~100MPa.

22. The method for preparing high-speed steel cutting tools by injection molding as described in claim 1, characterized in that, The sintering process includes hot debinding and pressure sintering. The degreasing temperature T1 is 400~600℃, and the time is not less than 5h; the gas pressure sintering temperature is 1100~1300℃, the pressure is 2.0~5.0MPa, and the gas pressure sintering time is 2~5h.

23. The method for preparing high-speed steel cutting tools by injection molding as described in claim 1, characterized in that, The heat treatment process includes quenching, deep cooling and tempering; among them, the quenching process is carried out under vacuum, the temperature is 1180~1210℃, the holding time is not less than 30min, and the quenching medium is inert gas or oil. The cryogenic temperature is -80~-150℃, and the holding time is no less than 8 hours; The tempering temperature is 580~650℃; the number of tempering cycles is 2~6, and each tempering cycle is no less than 1.5 hours.

24. A high-speed steel cutting tool prepared by the method according to any one of claims 1 to 23.

25. The application of a high-speed steel cutting tool prepared by the method according to any one of claims 1 to 23, characterized in that, It is then used to prepare band saw or welded composite bands.

26. The application of a high-speed steel cutting tool prepared by the method according to any one of claims 1 to 23, characterized in that, It is prepared by nickel-free welding to produce saws or by nickel-free welding to produce welded composite strips.

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