A method for preparing powder high-speed steel billets, powder high-speed steel billets and their applications

Abstract

This invention discloses a method for preparing powdered high-speed steel billets, the powdered high-speed steel billets themselves, and their applications, relating to the field of advanced manufacturing technology for metallic materials. This invention employs a high-frequency induction hot pressing sintering method to prepare powdered high-speed steel billets, enabling rapid manufacturing of these billets and achieving product performance comparable to that obtained through traditional hot isostatic pressing (HIP). Compared to traditional HIP methods, this process is simpler, has a shorter cycle time, and avoids the need for encapsulation, thus reducing costs and improving safety. The powdered high-speed steel prepared by this invention achieves a density of 98.5%, a microhardness of 365 Hv, and tensile strength and yield strength of 723 MPa and 687 MPa, respectively. This allows for short-process, low-cost preparation of powdered high-speed steel billets, which can be used to manufacture hardware cutters, mechanical molds, etc.

Description

Technical Field

[0001] This invention relates to the field of advanced manufacturing technology for metallic materials, and more specifically, to a method for preparing powder high-speed steel billets, powder high-speed steel billets, and their applications. Background Technology

[0002] Powder metallurgy high-speed steel is a high-alloy, high-performance tool and die steel material prepared using powder metallurgy technology. Compared to traditional cast high-speed steel, powder metallurgy high-speed steel eliminates macroscopic segregation of alloy components, resulting in fine and uniformly distributed carbides. It possesses excellent comprehensive properties such as high hardness, high corrosion resistance, high red hardness, and high wear resistance, making it widely used in machining equipment such as taps, drills, cutting tools, and stamping dies. With the increasing demands for high-performance tool and die materials from the machinery manufacturing industry and the growing market demand, powder metallurgy high-speed steel now accounts for approximately 10% of the annual high-speed steel production.

[0003] Currently, domestic and international manufacturers mainly use hot isostatic pressing (HIP) technology to produce powder high-speed steel billets. This process utilizes gas as a pressure medium, applying high temperature and pressure to sinter and densify the powder within the cladding. The high pressure significantly reduces the sintering temperature of the powder, resulting in HIP powder high-speed steel with advantages such as fine grains, uniform carbide distribution, and high density. However, the cladding + HIP process is costly, has a long process flow, and carries the risk of cladding failure ("burst") if the cladding is not properly sealed.

[0004] Therefore, there is an urgent need to develop simple and easy-to-implement production processes with short workflows to improve production efficiency and reduce equipment costs.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing powder high-speed steel billets, powder high-speed steel billets and their applications, aiming to shorten the process flow and reduce process costs while ensuring product performance.

[0007] This invention is implemented as follows:

[0008] In a first aspect, the present invention provides a method for preparing powder high-speed steel billets, comprising:

[0009] The raw material powder is filled into the mold and placed in a high-frequency induction hot pressing sintering furnace for pre-pressing, heating and pressurizing, heat preservation and pressurizing, and cooling and pressurizing stages in sequence.

[0010] In an optional implementation, during the heating and pressurization stage, the temperature is controlled to rise to 1000℃-1250℃ and the pressure is controlled to rise to 2MPa-50MPa.

[0011] Preferably, during the heating and pressurization stage, the temperature is controlled to 1000℃-1100℃ and the pressure is controlled to 30MPa-50MPa.

[0012] In an optional implementation, during the heating and pressurization stage, the heating rate is controlled to be 10℃ / min-100℃ / min, and the pressurization rate is controlled to be 0.5MPa / min-20MPa / min.

[0013] Preferably, during the heating and pressurization stage, the heating rate is controlled at 80℃ / min-100℃ / min, and the pressurization rate is controlled at 0.5MPa / min-5MPa / min.

[0014] In an optional implementation, during the heat preservation and pressure preservation stage, the heat preservation and pressure preservation time is controlled to be 10 min to 120 min, preferably 10 min to 60 min.

[0015] In an optional implementation, the cooling and depressurization stage controls the cooling rate to be 5℃ / min-100℃ / min and the depressurization rate to be 0.5MPa / min-20MPa / min.

[0016] Preferably, during the cooling and depressurization stage, the cooling rate is controlled at 80℃ / min-100℃ / min, and the depressurization rate is controlled at 0.5MPa / min-5MPa / min;

[0017] Preferably, demolding is performed after the pressure is completely released and the temperature drops to 15℃-30℃.

[0018] In an optional implementation, during the pre-compression stage, the pressure is controlled at 2MPa-30MPa and the processing time is 5min-30min.

[0019] In an optional embodiment, the raw material powder contains, by mass percentage, 20%-22% chromium, 1.0%-2.0% molybdenum, 1.0%-1.5% cobalt, 0.6%-1.0% vanadium, 1.9%-2.2% carbon, and the balance is iron;

[0020] Preferably, the sphericity of the raw material powder is greater than 0.8.

[0021] In an optional embodiment, the raw material powder is divided into fine powder, medium powder and coarse powder according to the particle size range, with the particle size range of fine powder being 2μm-66μm, medium powder being 5μm-209μm, and coarse powder being 71μm-400μm.

[0022] Preferably, the raw material powder is medium-sized powder.

[0023] Secondly, the present invention provides a powder high-speed steel billet, which is prepared by any of the methods described in the foregoing embodiments.

[0024] Thirdly, the present invention also provides the application of the powder high-speed steel billet provided in the above embodiments in the preparation of hardware cutlery or mechanical molds.

[0025] This invention offers the following advantages: It employs a high-frequency induction hot pressing sintering method to prepare powder high-speed steel billets, enabling rapid manufacturing of these billets. The resulting product performance reaches the level of products produced by traditional hot isostatic pressing (HIP). Compared to traditional HIP methods, this invention features a simpler process, shorter cycle time, and avoids the need for encapsulation, thus reducing costs and improving safety.

[0026] The powdered high-speed steel prepared by this invention has a density of 98.5%, a microhardness of 365Hv, a tensile strength of 723MPa, and a yield strength of 687MPa. It can realize the short-process and low-cost preparation of powdered high-speed steel billets. The resulting powdered high-entropy steel billets can be used to manufacture hardware cutters, mechanical molds, etc. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a diagram of a high-frequency induction heating sintering apparatus.

[0029] Figure 2 The particle size distribution of the three types of powders used in this invention;

[0030] Figure 3 This is a scanning electron microscope (SEM) image of the powder high-speed steel billet prepared in Example 1;

[0031] Figure 4 (a) shows the microstructure of the powdered high-speed steel prepared in Example 1; (b) shows an enlarged view of the red area in (a).

[0032] Figure 5 The fracture morphology of the powder high-speed steel prepared in Example 1 is shown in (a); (b) represents the overall fracture morphology; (c) represents region 1 in (a); and (d) represents region 2 in (a). Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0034] High-frequency induction heated sintering (HFIHS) heats the powder by generating eddy currents within the powder under the influence of a high-frequency alternating current through an inductor coil wound around the outside of the mold. This self-heating process is as follows: Figure 1 As shown. Compared with hot isostatic pressing, it has higher energy utilization and working efficiency, and can achieve short-time densification sintering; it avoids the preparation of a cladding, which can reduce costs and improve safety.

[0035] Traditional sintering processes for preparing powdered high-speed steel billets mostly employ heating methods such as thermal radiation and heat conduction, resulting in significant temperature gradients and a lack of self-heating from the powder. The sintering method provided in this invention, however, exhibits self-heating, leading to higher sintering efficiency, and impurities within the powder can be melted through self-heating. Furthermore, the absence of a significant temperature gradient in the self-heating method results in more uniform heating, which is beneficial for improving product density.

[0036] This invention provides a method for preparing powder high-speed steel billets, comprising the following steps:

[0037] S1, Raw material powder filling

[0038] The raw material powder is filled into the mold, and the filling volume accounts for 50%-80% of the total volume of the mold. The material of the mold is not limited, such as common high-temperature resistant materials, specifically graphite.

[0039] In some embodiments, the raw material powder contains, by mass percentage, 20%-22% chromium, 1.0%-2.0% molybdenum, 1.0%-1.5% cobalt, 0.6%-1.0% vanadium, and 1.9%-2.2% carbon, with the balance being iron. Raw material powders with component contents within the above ranges are suitable for use in the sintering method provided in the embodiments of the present invention, and the resulting powdered high-speed steel billets exhibit properties such as density that meet the process requirements. The raw material powder can be spherical or near-spherical, with a sphericity greater than 0.8.

[0040] Specifically, by mass percentage, the chromium content in the raw material powder can be 20.0%, 20.5%, 21.0%, 21.5%, 22.0%, etc.; the molybdenum content can be 1.0%, 1.5%, 2.0%, etc.; the cobalt content can be 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, etc.; the vanadium content can be 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, etc.; and the carbon content can be 1.9%, 2.0%, 2.1%, 2.2%, etc.

[0041] In some embodiments, such as Figure 2 As shown, the raw material powder is divided into fine powder, medium powder, and coarse powder according to particle size range. The particle size range of fine powder is 2μm-66μm, that of medium powder is 5μm-209μm, and that of coarse powder is 71μm-400μm; preferably, the raw material powder is medium powder. Through particle size distribution, the maximum values ​​of the loose bulk density and tapped density of the powder are achieved. Specifically, particle size refers to the average particle size Dv50.

[0042] S2, High-frequency induction hot pressing sintering

[0043] A mold containing raw material powder is placed in a high-frequency induction hot pressing sintering furnace, followed by a pre-pressing stage, a heating and pressurizing stage, a holding and pressurizing stage, and a cooling and depressurizing stage. By using a high-frequency induction hot pressing sintering furnace and controlling the sintering process, the resulting high-speed steel billet powder exhibits superior performance, reaching or even exceeding the performance of products prepared by conventional hot isostatic pressing methods. The specific model of the high-frequency induction hot pressing sintering furnace is not limited; it can be, for example, the Guangneng Equipment-HPS-200.

[0044] In some embodiments, during the pre-compression stage, the pressure is controlled at 2MPa-30MPa, and the processing time is 5min-30min. Pre-compression ensures that the powder particles are in close contact and densely packed. Specifically, during the pre-compression stage, the temperature is not regulated, and the pressure inside the mold can be controlled at 2MPa, 5MPa, 10MPa, 15MPa, 20MPa, 25MPa, 30MPa, etc.

[0045] In some embodiments, during the heating and pressurization stage, the temperature is controlled to 1000℃-1250℃ and the pressure to 2MPa-50MPa; preferably, the temperature is controlled to 1000℃-1100℃ and the pressure to 30MPa-50MPa. By regulating the final temperature and pressure of the heating and pressurization stage, the temperature and pressure of the holding and pressing stage are further controlled, making the sintering temperature and pressure more suitable for the sintering of the raw material powder, so that the density and comprehensive properties of the sintered high-speed steel billet meet the process requirements.

[0046] Specifically, during the heating and pressurization stage, the final temperature after heating can be controlled to be 1000℃, 1050℃, 1100℃, 1150℃, 1200℃, 1250℃, etc.; and the final pressure after pressurization can be controlled to be 2MPa, 5MPa, 10MPa, 15MPa, 20MPa, 25MPa, 30MPa, 35MPa, 40MPa, 45MPa, 50MPa, etc.

[0047] Furthermore, during the heating and pressurization stages, the heating rate is controlled at 10℃ / min-100℃ / min, and the pressurization rate at 0.5MPa / min-20MPa / min; preferably, the heating rate is controlled at 80℃ / min-100℃ / min, and the pressurization rate at 0.5MPa / min-5MPa / min. By regulating the heating and pressurization rates, excessively rapid heating or pressurization can prevent it from affecting product performance, while excessively slow heating or pressurization can prolong the production cycle.

[0048] Specifically, during the heating and pressurization stages, the heating rate can be controlled at 10℃ / min, 20℃ / min, 30℃ / min, 40℃ / min, 50℃ / min, 60℃ / min, 70℃ / min, 80℃ / min, 90℃ / min, 100℃ / min, etc.; and the pressurization rate can be controlled at 0.5MPa / min, 1.0MPa / min, 3.0MPa / min, 5.0MPa / min, 8.0MPa / min, 10.0MPa / min, 15.0MPa / min, 20.0MPa / min, etc.

[0049] In some embodiments, during the heat preservation and pressure holding stage, the heat preservation and pressure holding time is controlled to be 10 min-120 min, preferably 10 min-60 min, such as 10 min, 30 min, 50 min, 60 min, 80 min, 100 min, 120 min, etc. Controlling the heat preservation and pressure holding time within the above range is preferable to achieve better density in the prepared high-speed powder steel billet.

[0050] In some embodiments, the cooling and depressurization stage controls the cooling rate to be 5°C / min-100°C / min and the depressurization rate to be 0.5MPa / min-20MPa / min; preferably, the cooling rate is controlled to be 80°C / min-100°C / min and the depressurization rate is 0.5MPa / min-5MPa / min. It is preferable to control the cooling and depressurization rates within the above ranges to prevent excessively rapid temperature or pressure reduction from affecting product performance.

[0051] Specifically, during the cooling and depressurization stage, the cooling rate can be controlled at 5℃ / min, 10℃ / min, 20℃ / min, 30℃ / min, 40℃ / min, 50℃ / min, 60℃ / min, 70℃ / min, 80℃ / min, 90℃ / min, 100℃ / min, etc.; the depressurization rate can be controlled at 0.5MPa / min, 1.0MPa / min, 3.0MPa / min, 5.0MPa / min, 8.0MPa / min, 10.0MPa / min, 15.0MPa / min, 20.0MPa / min, etc.

[0052] S3, Demolding

[0053] After the pressure is completely released and the temperature drops to 15℃-30℃ (e.g., room temperature), the powder high-speed steel billet is demolded and the mechanical properties of the obtained powder high-speed steel are tested.

[0054] This invention also provides a powder high-speed steel billet, which is prepared by the method provided in this invention. The powder high-speed steel prepared by this invention can reach a density of 98.5%, a microhardness of 365Hv, a tensile strength of 723MPa and a yield strength of 687MPa. The obtained powder high-entropy steel billet can be used to manufacture hardware cutters, mechanical molds, etc.

[0055] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0056] Example 1

[0057] This embodiment provides a method for preparing powder high-speed steel billets, the specific steps of which are as follows:

[0058] (1) Select medium-sized powder (particle size distribution 5-209μm, refer to specific details) Figure 2 ), and fill it into the graphite mold.

[0059] By mass percentage, the raw material powder contains 21% chromium, 1.5% molybdenum, 1.2% cobalt, 0.8% vanadium, 2.0% carbon, and the balance is iron.

[0060] (2) Place the mold into a high-frequency induction hot pressing sintering furnace and evacuate it to 1x10. -1 The preset pressure is 30 MPa, and the processing time is 30 min.

[0061] (3) Heat to 1050℃ and pressurize to 50MPa at a heating rate of 100℃ / min and a pressurization rate of 5MPa / min.

[0062] (4) After the temperature and pressure increase in step (3), maintain the temperature and pressure for 10 minutes.

[0063] (5) Control the cooling rate to 100℃ / min and the pressure reduction rate to 5MPa / min. After cooling (to room temperature of about 25℃) and depressurizing, remove the mold.

[0064] Performance testing: The microstructure of the sintered sample is characterized and its mechanical properties are tested.

[0065] The results showed that the sample had a density of 98.5%, a microhardness of 365 Hv, and tensile strength and yield strength of 723 MPa and 687 MPa, respectively.

[0066] Figure 3 The scanning electron microscope image of the powder high-speed steel billet prepared in Example 1 shows that the surface of the billet has a high density, a small number of pores, and a small pore size.

[0067] Figure 4 The microstructure of the powdered high-speed steel prepared in Example 1 shows that the precipitate particles are distributed along the grain boundaries and are relatively uniform.

[0068] Figure 5 The fracture morphology of the powdered high-speed steel prepared in Example 1 shows that the fracture surface exhibits dissociative fracture characteristics and carbide particles can be found.

[0069] Example 2

[0070] This embodiment provides a method for preparing powder high-speed steel billets, the specific steps of which are as follows:

[0071] (1) Same as step (1) in Example 1.

[0072] (2) Place the mold into a high-frequency induction hot pressing sintering furnace and evacuate it to 1x10. -1 The preset pressure is 30 MPa, and the processing time is 30 min.

[0073] (3) Heat to 1050℃ and pressurize to 50MPa at a heating rate of 100℃ / min and a pressurization rate of 0.5MPa / min.

[0074] (4) After the temperature and pressure increase in step (3), maintain the temperature and pressure for 10 minutes.

[0075] (5) Control the cooling rate to 80℃ / min and the pressure reduction rate to 0.5MPa / min. After cooling (to room temperature of about 25℃) and depressurizing, demold and remove the product.

[0076] The results showed that the sample in this embodiment had a density of 97.8%, a microhardness of 343 Hv, and tensile strength and yield strength of 709 MPa and 675 MPa, respectively.

[0077] Example 3

[0078] This embodiment provides a method for preparing powder high-speed steel billets, the specific steps of which are as follows:

[0079] (1) Same as step (1) in Example 1.

[0080] (2) Place the mold into a high-frequency induction hot pressing sintering furnace and evacuate it to 1x10. -1 The preset pressure is 30 MPa, and the processing time is 5 minutes.

[0081] (3) Heat to 1050℃ and pressurize to 50MPa at a heating rate of 100℃ / min and a pressurization rate of 0.5MPa / min.

[0082] (4) After the temperature and pressure increase in step (3), maintain the temperature and pressure for 10 minutes.

[0083] (5) Control the cooling rate to 100℃ / min and the pressure reduction rate to 0.5MPa / min. After cooling (to room temperature of about 25℃) and depressurizing, remove the mold.

[0084] The results showed that the sample in this embodiment had a density of 97.1%, a microhardness of 341 Hv, and tensile strength and yield strength of 705 MPa and 665 MPa, respectively.

[0085] Example 4

[0086] The only difference from Example 1 is that in step (3), the temperature is increased to 1000°C and the pressure is increased to 5MPa.

[0087] The results showed that the sample in this embodiment had a density of 95.3%, a microhardness of 322 Hv, and tensile strength and yield strength of 653 MPa and 598 MPa, respectively.

[0088] Example 5

[0089] The only difference from Example 1 is that in step (3), the temperature is increased to 1250°C and the pressure is increased to 50MPa.

[0090] The results showed that the sample in this embodiment had a density of 98.1%, a microhardness of 312 Hv, and tensile strength and yield strength of 643 MPa and 582 MPa, respectively.

[0091] Example 6

[0092] The only difference from Example 1 is that in step (3), the temperature is increased to 1050°C and the pressure is increased to 30MPa.

[0093] The results showed that the sample in this embodiment had a density of 95.4%, a microhardness of 362 Hv, and tensile strength and yield strength of 702 MPa and 651 MPa, respectively.

[0094] Example 7

[0095] The only difference from Example 1 is that step (4) involves heat preservation and pressure maintenance for 60 minutes.

[0096] The results showed that the sample in this embodiment had a density of 97.8%, a microhardness of 352 Hv, and tensile strength and yield strength of 687 MPa and 601 MPa, respectively.

[0097] Example 8

[0098] The only difference from Example 1 is that step (4) involves heat preservation and pressure maintenance for 120 minutes.

[0099] The results showed that the sample in this embodiment had a density of 97.8%, a microhardness of 356 Hv, and tensile strength and yield strength of 678 MPa and 587 MPa, respectively.

[0100] Example 9

[0101] The only difference from Example 1 is that step (2) presets the pressure to 2 MPa.

[0102] The results showed that the sample in this embodiment had a density of 93.5%, a microhardness of 312 Hv, and tensile strength and yield strength of 565 MPa and 499 MPa, respectively.

[0103] Example 10

[0104] The only difference from Example 1 is that the heating / cooling rate in steps (3) and (5) is 80°C / min.

[0105] The results showed that the sample in this embodiment had a density of 98.1%, a microhardness of 340 Hv, and tensile strength and yield strength of 633 MPa and 573 MPa, respectively.

[0106] Comparative Example 1

[0107] This comparative example provides a conventional hot isostatic pressing (HIP) sintering process, with the following specific steps: The powder or powder compact is loaded into a casing; the gas adsorbed on the powder surface, in the gaps between powder particles, and inside the casing is removed; the casing is vacuum-sealed and placed in a hot isostatic press, heated and pressurized to 1050℃ and 50MPa, and held at that temperature and pressure for 2 hours; after removing the sample, the casing is removed mechanically or by acid leaching to obtain the product.

[0108] The results showed that the comparative sample had a density of 98.5%, a microhardness of 356 Hv, and tensile strength and yield strength of 717 MPa and 593 MPa, respectively.

[0109] Comparative Example 2

[0110] The only difference from Example 1 is that step (2) is omitted.

[0111] The results showed that the density of the comparative sample was 87.2%, the microhardness was 345 Hv, and the tensile strength and yield strength reached 522 MPa and 456 MPa, respectively.

[0112] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing powder high-speed steel billets, characterized in that, include: The raw material powder is filled into the mold and placed in a high-frequency induction hot pressing sintering furnace for the pre-pressing stage, the heating and pressurizing stage, the heat preservation and pressurizing stage, and the cooling and pressurizing stage in sequence. By mass percentage, the raw material powder contains 20%-22% chromium, 1.0%-2.0% molybdenum, 1.0%-1.5% cobalt, 0.6%-1.0% vanadium, 1.9%-2.2% carbon, and the balance is iron; During the pre-compression stage, the pressure is controlled at 2MPa-30MPa, and the processing time is 5min-30min. During the heating and pressurization stage, the temperature is controlled to rise to 1000℃-1250℃ and the pressure is controlled to rise to 2MPa-50MPa. During the heat preservation and pressure holding stage, the heat preservation and pressure holding time is controlled to be 10min-120min; The cooling and depressurization stage controls the cooling rate to be 5℃ / min-100℃ / min and the depressurization rate to be 0.5MPa / min-20MPa / min.

2. The method according to claim 1, characterized in that, During the heating and pressurization stage, the temperature is controlled to rise to 1000℃-1100℃ and the pressure is controlled to rise to 30MPa-50MPa.

3. The method according to claim 2, characterized in that, During the heating and pressurization stage, the heating rate is controlled at 10℃ / min-100℃ / min, and the pressurization rate is controlled at 0.5MPa / min-20MPa / min.

4. The method according to claim 3, characterized in that, During the heating and pressurization stage, the heating rate is controlled at 80℃ / min-100℃ / min, and the pressurization rate is controlled at 0.5MPa / min-5MPa / min.

5. The method according to claim 1, characterized in that, During the heat preservation and pressure holding stage, the heat preservation and pressure holding time is controlled to be 10min-60min.

6. The method according to claim 1, characterized in that, The cooling and depressurization stage controls the cooling rate to be 80℃ / min-100℃ / min and the depressurization rate to be 0.5MPa / min-5MPa / min.

7. The method according to claim 6, characterized in that, After the pressure is completely released and the temperature drops to 15℃-30℃, demold.

8. The method according to claim 1, characterized in that, The sphericity of the raw material powder is greater than 0.

8.

9. The method according to claim 8, characterized in that, The raw material powder is divided into fine powder, medium powder and coarse powder according to the particle size range. The particle size range of the fine powder is 2μm-66μm, the particle size range of the medium powder is 5μm-209μm, and the particle size range of the coarse powder is 71μm-400μm.

10. The method according to claim 1, characterized in that, The raw material powder is medium-sized powder, and the particle size range of the medium-sized powder is 5μm-209μm.

11. A powder high-speed steel billet, characterized in that, It is prepared by the method according to any one of claims 1-10.

12. The application of the powder high-speed steel billet according to claim 11 in the preparation of hardware cutters or mechanical molds.

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