A wear-resistant cermet composite material for a blast furnace opening drill and a preparation method thereof

Abstract

This invention discloses a wear-resistant metal-ceramic composite material for blast furnace opening drills and its preparation method, belonging to the technical field of blast furnace opening drills. The preparation method of this wear-resistant metal-ceramic composite material for blast furnace opening drills includes: mixing WC powder and ZrC powder to obtain a mixture; immersing the mixture in an impregnation solution at 55-65°C, followed by filtration to obtain a first powder; mixing the first powder, HEC powder, and Cr₃C₂ powder, placing the mixture in a plasma device, and treating it at 550-600°C under an inert gas atmosphere to obtain a second powder; ball milling the second powder, grinding balls, and media to obtain a mixed powder; loading the mixed powder into a mold, applying pressure, and holding the pressure to obtain a green body; and calcining the green body to obtain the wear-resistant metal-ceramic composite material. The material obtained by this invention has high wear resistance and high-temperature resistance.

Description

Technical Field

[0001] This invention relates to the field of blast furnace opening drill tools, specifically to a wear-resistant metal-ceramic composite material for blast furnace opening drill tools and its preparation method. Background Technology

[0002] Blast furnace taphole drills are specialized tools used in the steelmaking process to drill through the dense clay layer and refractory material layer at the blast furnace taphole, creating a channel for the discharge of molten iron / slag. They are core equipment for blast furnace operations. A typical structure consists of three parts: a drill rod, a drill bit (the working core), and a connecting joint. During operation, the blast furnace taphole drill provides torque (500-1000 N·m) and drilling pressure (10-30 kN), driving the drill bit to rotate and cut, ultimately forming a taphole channel with a diameter of 80-150 mm, ensuring continuous discharge of molten iron.

[0003] Based on differences in blast furnace volume and operating conditions, drilling tools can be classified as follows:

[0004] Drilling tools for small and medium-sized blast furnaces (volume < 2000m³) 3 ): Mostly uses single-tooth or three-tooth drill bits, suitable for low-frequency opening (once a day);

[0005] Large / Extra-large blast furnace drilling tools (volume ≥ 2000m³) 3 ): Multi-tooth composite drill bits or insert drill bits are required, which are suitable for high-frequency opening (2-3 times a day) and must be able to withstand higher temperatures and impact loads.

[0006] The operating conditions at the blast furnace taphole are extreme, requiring drilling tools to meet high wear resistance and high temperature resistance requirements to ensure service life and operational safety. Improving the wear resistance and high temperature resistance of wear-resistant metal-ceramic composite materials used in blast furnace taphole drilling tools is a technical problem that needs to be addressed with existing technology. Summary of the Invention

[0007] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a wear-resistant metal-ceramic composite material for blast furnace opening drills and its preparation method, thereby solving the technical problem of how to improve the wear resistance and high-temperature resistance of blast furnace opening drills in the prior art.

[0008] To achieve the above-mentioned technical objectives, the present invention provides a method for preparing a wear-resistant metal-ceramic composite material for blast furnace opening drill bits, comprising the following steps:

[0009] S1. Mix WC powder and ZrC powder to obtain a mixture;

[0010] S2. The mixture is immersed in an impregnation solution at 55-65°C, and then filtered to obtain the first powder; the impregnation solution contains Co. 2+ Mo 4+ and Y 3+ ;

[0011] S3. Mix the first powder, HEC powder and Cr3C2 powder, place them in a plasma device, and process them at 550-600°C under an inert gas atmosphere to obtain the second powder.

[0012] S4. The second powder, grinding balls, and media are mixed and ball-milled to obtain a mixed powder; the mixed powder is loaded into a mold, pressure is applied, and pressure is maintained to obtain a green body;

[0013] S5. The green blank is heated to 800-900℃ and held at 30-40MPa for heat treatment. Then, the temperature is further increased to 1200-1300℃ and held at 40-50MPa for heat treatment. Then, the temperature is further increased to 1750-1800℃ and held at 60-70MPa for heat treatment to obtain the wear-resistant metal-ceramic composite material.

[0014] In any embodiment, in step S2, Co in the impregnation solution 2+ The concentration is 0.3-0.5 mol / L, Mo 4 + The concentration is 0.1-0.2 mol / L, Y 3+ The concentration is 0.03-0.05 mol / L.

[0015] In any embodiment, before step S3, the first powder is placed in a tube furnace and heated to 780-850°C by introducing a reducing atmosphere for heat preservation treatment.

[0016] In any embodiment, the reducing atmosphere is a mixture of nitrogen and hydrogen, wherein the volume ratio of nitrogen to hydrogen is (7-8):(2-3).

[0017] In any embodiment, in step S3, the first powder, HEC powder and Cr3C2 powder are mixed in a mass ratio of 100:(15-20):(5-10).

[0018] In any embodiment, in step S4, the medium is anhydrous ethanol, and the mass ratio of the powder balls is (12-15):1; the solid-liquid mass ratio of the second powder and the medium is 1:(2-2.5).

[0019] In any embodiment, in step S4, a pressure of 180-220 MPa is applied and held for 12-18 minutes to obtain the green blank.

[0020] In any embodiment, in step S3, the flow rate of the inert gas is 120-150 mL / min; and / or, the treatment is carried out at 550-600°C for 30-45 min.

[0021] In any embodiment, in step S5, the temperature is raised to 800-900℃ and held at 30-40MPa for 3-5 minutes, and / or the temperature is raised to 1200-1300℃ and held at 40-50MPa for 5-8 minutes; and / or the temperature is raised to 1750-1800℃ and held at 60-70MPa for 10-15 minutes.

[0022] In addition, the present invention also proposes a wear-resistant metal-ceramic composite material for blast furnace opening drills, which is prepared by the above preparation method.

[0023] Compared with the prior art, the beneficial effects of the present invention include: the WC-ZrC composite hard phase provides high hardness and high temperature stability, and the "solution impregnation method" is used: Co 2+ Mo 4+ Y 3+ Existing in an ionic state in solution, it uniformly adheres to the surface of WC-ZrC composite powder through electrostatic adsorption (adsorption deviation <5%). After subsequent drying, it forms a nanoscale metallic binder phase, which can completely coat each WC-ZrC particle, avoiding the shedding of hard phase caused by "local lack of binder phase". The first powder, HEC powder, and Cr3C2 powder are mixed and then subjected to plasma treatment. Through the physicochemical action of high-energy plasma, the surface activity of the powder is improved, laying the foundation for subsequent sintering and densification. The three-step sintering, through the coordinated control of pressure and temperature, achieves high density and low internal stress of the material, thereby endowing the material with high wear resistance, high temperature resistance, thermal shock resistance, and corrosion resistance. Detailed Implementation

[0024] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60~120 and 80~110 are listed for a specific parameter, it is also expected that ranges of 60~110 and 80~120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this application, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0025] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0026] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0027] This specific embodiment provides a method for preparing a wear-resistant metal-ceramic composite material for blast furnace opening drill bits, including the following steps:

[0028] S1. Mix WC powder (100-150nm) and ZrC powder (30-50nm) at a mass ratio of 4:(1-1.5) to obtain a mixture.

[0029] S2. Preparation of impregnation solution: Using deionized water as solvent, dissolve cobalt nitrate (Co(NO3)2) and ammonium molybdate ((NH4)6Mo7O) 24 • 4H2O), yttrium nitrate (Y(NO3)3), control ion concentration: Co²⁺ 0.3-0.5 mol / L, Mo 4⁺ 0.1-0.2 mol / L, Y³⁺ 0.03-0.05 mol / L; add the mixture to the impregnation solution, stir at 55-65℃ (180-220 rpm) and soak for 3-5 hours to ensure uniform loading of metal ions on the surface of the composite powder; after filtration, wash 2-3 times with deionized water, and vacuum dry at 60-65℃ for 6-8 hours to obtain the first powder (WC-ZrC surface loaded with Co, Mo, and Y precursors). Multi-component co-impregnation achieves atomic-level uniform distribution of Co-Mo-Y, avoiding agglomeration of the binder phase.

[0030] In some embodiments, the process further includes placing the first powder in a tube furnace, introducing a reducing atmosphere (N2:H2 = (7-8):(2-3), volume ratio), heating at a rate of 5-8 °C / min, heating to 780-850 °C and holding for 5-7 h; then naturally cooling to room temperature to obtain the treated first powder (the precursor is reduced to elemental Co and Mo, and Y is converted to Y2O3). The metal elements in the first powder (WC-ZrC surface loaded with Co, Mo, and Y precursors) exist in ionic or compound forms (e.g., Co). 2+ With cobalt nitrate, Mo 4+ With ammonium molybdate, Y 3+ (When yttrium nitrate is attached), direct use in subsequent processes will introduce impurities such as O and N. Reduction treatment can remove harmful impurities and generate functional phases in situ, thereby improving the stability of subsequent processes.

[0031] S3. Plasma Activation: The first powder is mixed with HEC powder (80-120nm) and Cr3C2 powder (50-80nm) at a mass ratio of 100:(15-20):(5-10), and placed in a plasma device with a vacuum degree of 10⁻. 4 Pa, argon flow rate 120-150 mL / min, 550-600℃ for 30-45 min to obtain the second powder;

[0032] S4. Add the second powder to a horizontal ball mill with cemented carbide grinding balls (5mm in diameter), a ball-to-powder mass ratio of (12-15):1, and anhydrous ethanol as the medium (solid-to-liquid mass ratio 1:(2-2.5)). Mill at 380-420 rpm for 36-48 hours. After drying (vacuum drying at 50-55℃ for 4-6 hours), pass through a 140-mesh sieve to obtain a mixed powder. Plasma activation is used to increase the surface energy of the powder, combined with high-energy ball milling to ensure uniform dispersion of the components. Load the mixed powder into a graphite mold (matching the drill bit size), apply a pressure of 180-220 MPa, and hold for 12-18 minutes to obtain a green body (density ≥68%).

[0033] S5. The green body is sintered using a three-stage heating process:

[0034] First stage (degreasing): Heat to 800-900℃ at 80-100℃ / min, hold at 30-40MPa for 3-5min to remove residual impurities;

[0035] Second stage (pre-firing): Heat to 1200-1300℃ at 100-120℃ / min, hold at 40-50MPa for 5-8min, and initially densify;

[0036] The third stage (densification): heat up to 1750-1800℃ at 100-120℃ / min, hold at 60-70MPa for 10-15min to achieve complete particle bonding;

[0037] After sintering, the product is cooled in the furnace (15℃ / min before 800℃, 8℃ / min from 800℃ to 300℃, and then naturally cooled after 300℃) to obtain the finished product.

[0038] This specific embodiment also proposes a wear-resistant metal-ceramic composite material for blast furnace opening drills, which is prepared by the above-described preparation method.

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0040] In this invention, the terms "some embodiments," "this embodiment," and examples are used to describe a subset of all possible embodiments. However, it is understood that "some embodiments" can be the same subset or different subsets of all possible embodiments and can be combined with each other without conflict.

[0041] If the application documents contain similar descriptions such as "first / second", the following explanation shall be added: In the following description, the terms "first / second / third" are used only to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments described herein can be implemented in a different order than that described herein.

[0042] In this embodiment, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, object A and / or object B can represent three situations: object A exists alone, object A and object B exist simultaneously, and object B exists alone. The HEC powder in this invention is derived from existing technology. The HEC powder in the following examples or comparative examples is prepared by the following steps: using anhydrous ethanol as solvent and tungsten carbide balls as the ball milling medium, nano-sized TiC (purity 99.6 wt.%, particle size 50 nm), ZrC (purity 99.7 wt.%, particle size 50 nm), NbC (purity 99.8 wt.%, particle size 50 nm), HfC (purity 99.5 wt.%, particle size 80 nm), and TaC (purity 99.7 wt.%, particle size 90 nm) powders are mixed in a molar ratio of 1:1:1:1:1, and the mixture is ball-milled at 200 r / min for 10 h. After drying and sieving, a carbide mixed powder, abbreviated as HEC powder, is obtained. Example 1

[0043] This embodiment proposes a wear-resistant metal-ceramic composite material for blast furnace opening drills, which is prepared by the following steps:

[0044] S1. Mix WC powder (100-150nm) and ZrC powder (30-50nm) at a mass ratio of 4:1 to obtain a mixture.

[0045] S2. Preparation of impregnation solution: Using deionized water as solvent, dissolve cobalt nitrate (Co(NO3)2) and ammonium molybdate ((NH4)6Mo7O) 24 • 4H2O), yttrium nitrate (Y(NO3)3), controlling ion concentrations: Co²⁺ 0.5 mol / L, Mo 4 Y⁺ 0.1 mol / L, Y³⁺ 0.04 mol / L; the mixture was added to the impregnation solution, stirred at 55℃ (200 rpm) and soaked for 5 h to ensure that the metal ions were uniformly loaded on the surface of the composite powder; after filtration, it was washed twice with deionized water and vacuum dried at 60℃ for 7 h to obtain the first powder.

[0046] S3. Plasma Activation: The first powder is mixed with HEC powder (80-120nm) and Cr3C2 powder (50-80nm) at a mass ratio of 100:15:8, and placed in a plasma device with a vacuum degree of 10⁻. 4 Pa, argon flow rate 120 mL / min, 550℃ for 40 min to obtain the second powder;

[0047] S4. Add the second powder to a horizontal ball mill with cemented carbide grinding balls (5mm in diameter), a ball-to-powder mass ratio of 12:1, and anhydrous ethanol as the medium (solid-to-liquid mass ratio 1:2.5). Mill at 400 rpm for 40 hours. After drying (vacuum drying at 50℃ for 6 hours), pass through a 140-mesh sieve to obtain a mixed powder. Plasma activation is used to increase the surface energy of the powder, combined with high-energy ball milling to ensure uniform dispersion of each component. Load the mixed powder into a graphite mold (matching the drill bit size), apply a pressure of 200 MPa, and hold for 15 minutes to obtain a green body (density ≥68%).

[0048] S5. The green body is sintered using a three-stage heating process:

[0049] First stage (degreasing): Heat to 850℃ at 90℃ / min, hold at 35MPa for 5min, and remove residual impurities;

[0050] Second stage (pre-firing): Heat to 1200℃ at 110℃ / min, hold at 45MPa for 5min, and initially densify;

[0051] The third stage (densification): the temperature is increased to 1800℃ at 100℃ / min and held at 60MPa for 15min to achieve complete particle bonding;

[0052] After sintering, the product is cooled in the furnace (15℃ / min before 800℃, 8℃ / min from 800℃ to 300℃, and then naturally cooled after 300℃) to obtain the finished product. Example 2

[0053] This embodiment proposes a wear-resistant metal-ceramic composite material for blast furnace opening drills, which is prepared by the following steps:

[0054] S1. Mix WC powder (100-150nm) and ZrC powder (30-50nm) at a mass ratio of 4:1.2 to obtain a mixture.

[0055] S2. Preparation of impregnation solution: Using deionized water as solvent, dissolve cobalt nitrate (Co(NO3)2) and ammonium molybdate ((NH4)6Mo7O) 24 • 4H2O), yttrium nitrate (Y(NO3)3), controlling ion concentrations: Co²⁺ 0.3mol / L, Mo 4 Y⁺ 0.2 mol / L, Y³⁺ 0.05 mol / L; add the mixture to the impregnation solution, stir at 60℃ (180-220 rpm) and soak for 4 h to ensure that the metal ions are uniformly loaded on the surface of the composite powder; after filtration, wash three times with deionized water, and vacuum dry at 65℃ for 6 h to obtain the first powder.

[0056] S3. Plasma Activation: The first powder is mixed with HEC powder (80-120nm) and Cr3C2 powder (50-80nm) at a mass ratio of 100:20:5, and placed in a plasma device with a vacuum degree of 10⁻. 4 Pa, argon flow rate 130 mL / min, 600℃ for 45 min to obtain the second powder;

[0057] S4. Add the second powder to a horizontal ball mill, using cemented carbide grinding balls (5mm diameter) at a ball-to-powder mass ratio of 13:1, and anhydrous ethanol as the medium (solid-to-liquid mass ratio 1:2). Mill at 380 rpm for 48 hours. After drying (vacuum drying at 55℃ for 5 hours), pass through a 140-mesh sieve to obtain a mixed powder. Plasma activation is used to enhance the surface energy of the powder, combined with high-energy ball milling to ensure uniform dispersion of each component. Load the mixed powder into a graphite mold (matching the drill bit size), apply a pressure of 220 MPa, and hold for 12 minutes to obtain a green body (density ≥68%).

[0058] S5. The green body is sintered using a three-stage heating process:

[0059] First stage (degreasing): Heat to 800℃ at 80℃ / min, hold at 30MPa for 4min, and remove residual impurities;

[0060] Second stage (pre-firing): Heat to 1250℃ at 100℃ / min, hold at 50MPa for 8min, and initially densify;

[0061] The third stage (densification): heating to 1750℃ at 110℃ / min and holding at 65MPa for 12min to achieve complete particle bonding;

[0062] After sintering, the product is cooled in the furnace (15℃ / min before 800℃, 8℃ / min from 800℃ to 300℃, and then naturally cooled after 300℃) to obtain the finished product. Example 3

[0063] This embodiment proposes a wear-resistant metal-ceramic composite material for blast furnace opening drills, which is prepared by the following steps:

[0064] S1. Mix WC powder (100-150nm) and ZrC powder (30-50nm) at a mass ratio of 4:1.5 to obtain a mixture.

[0065] S2. Preparation of impregnation solution: Using deionized water as solvent, dissolve cobalt nitrate (Co(NO3)2) and ammonium molybdate ((NH4)6Mo7O) 24 • 4H2O), yttrium nitrate (Y(NO3)3), controlling ion concentrations: Co²⁺ 0.4 mol / L, Mo 4Y⁺ 0.15 mol / L, Y³⁺ 0.03 mol / L; the mixture was added to the impregnation solution, stirred at 65℃ (180 rpm) and soaked for 3 h to ensure that the metal ions were uniformly loaded on the surface of the composite powder; after filtration, it was washed twice with deionized water and vacuum dried at 60℃ for 8 h to obtain the first powder.

[0066] S3. Plasma Activation: The first powder is mixed with HEC powder (80-120nm) and Cr3C2 powder (50-80nm) at a mass ratio of 100:18:10, and placed in a plasma device with a vacuum degree of 10⁻. 4 Pa, argon flow rate 150 mL / min, 570℃ for 30 min to obtain the second powder;

[0067] S4. Add the second powder to a horizontal ball mill, using cemented carbide grinding balls (5mm diameter) at a ball-to-powder mass ratio of 15:1, and anhydrous ethanol as the medium (solid-to-liquid mass ratio 1:2.2). Mill at 420 rpm for 36 hours. After drying (vacuum drying at 55℃ for 4 hours), pass through a 140-mesh sieve to obtain a mixed powder. Plasma activation is used to increase the surface energy of the powder, combined with high-energy ball milling to ensure uniform dispersion of each component. Load the mixed powder into a graphite mold (matching the drill bit size), apply a pressure of 180 MPa, and hold for 18 minutes to obtain a green body (density ≥68%).

[0068] S5. The green body is sintered using a three-stage heating process:

[0069] First stage (degreasing): Heat to 900℃ at 100℃ / min, hold at 40MPa for 3min to remove residual impurities;

[0070] Second stage (pre-firing): Heat to 1300℃ at 120℃ / min, hold at 40MPa for 6min, and initially densify;

[0071] The third stage (densification): the temperature is increased to 1800℃ at 120℃ / min, and held at 70MPa for 10min to achieve complete particle bonding;

[0072] After sintering, the product is cooled in the furnace (15℃ / min before 800℃, 8℃ / min from 800℃ to 300℃, and then naturally cooled after 300℃) to obtain the finished product. Example 4

[0073] S1. Mix WC powder (100-150nm) and ZrC powder (30-50nm) at a mass ratio of 4:1 to obtain a mixture.

[0074] S2. Preparation of impregnation solution: Using deionized water as solvent, dissolve cobalt nitrate (Co(NO3)2) and ammonium molybdate ((NH4)6Mo7O) 24• 4H2O), yttrium nitrate (Y(NO3)3), controlling ion concentrations: Co²⁺ 0.5 mol / L, Mo 4 ⁺0.1mol / L, Y³⁺0.04mol / L; the mixture was added to the impregnation solution, stirred at 55℃ (200rpm) and soaked for 5h to ensure that the metal ions were uniformly loaded on the surface of the composite powder; after filtration, it was washed twice with deionized water and vacuum dried at 60℃ for 7h to obtain the first powder; the process also included placing the first powder in a tube furnace, introducing a reducing atmosphere (N2:H2=7:3, volume ratio), heating at a rate of 5℃ / min, heating to 780℃ and holding for 7h; and naturally cooling to room temperature to obtain the treated first powder (the precursor was reduced to Co and Mo elements, and Y was converted to Y₂O₃).

[0075] S3. Plasma Activation: The treated first powder is mixed with HEC powder (80-120nm) and Cr3C2 powder (50-80nm) at a mass ratio of 100:15:8, and placed in a plasma device with a vacuum degree of 10⁻. 4 Pa, argon flow rate 120 mL / min, 550℃ for 40 min to obtain the second powder;

[0076] S4. Add the second powder to a horizontal ball mill with cemented carbide grinding balls (5mm in diameter), a ball-to-powder mass ratio of 12:1, and anhydrous ethanol as the medium (solid-to-liquid mass ratio 1:2.5). Mill at 400 rpm for 40 hours. After drying (vacuum drying at 50℃ for 6 hours), pass through a 140-mesh sieve to obtain a mixed powder. Plasma activation is used to increase the surface energy of the powder, combined with high-energy ball milling to ensure uniform dispersion of each component. Load the mixed powder into a graphite mold (matching the drill bit size), apply a pressure of 200 MPa, and hold for 15 minutes to obtain a green body (density ≥68%).

[0077] S5. The green body is sintered using a three-stage heating process:

[0078] First stage (degreasing): Heat to 850℃ at 90℃ / min, hold at 35MPa for 5min, and remove residual impurities;

[0079] Second stage (pre-firing): Heat to 1200℃ at 110℃ / min, hold at 45MPa for 5min, and initially densify;

[0080] The third stage (densification): the temperature is increased to 1800℃ at 100℃ / min and held at 60MPa for 15min to achieve complete particle bonding;

[0081] After sintering, the product is cooled in the furnace (15℃ / min before 800℃, 8℃ / min from 800℃ to 300℃, and then naturally cooled after 300℃) to obtain the finished product. Example 5

[0082] This embodiment proposes a wear-resistant metal-ceramic composite material for blast furnace opening drills, which is prepared by the following steps:

[0083] S1. Mix WC powder (100-150nm) and ZrC powder (30-50nm) at a mass ratio of 4:1.2 to obtain a mixture.

[0084] S2. Preparation of impregnation solution: Using deionized water as solvent, dissolve cobalt nitrate (Co(NO3)2) and ammonium molybdate ((NH4)6Mo7O) 24 • 4H2O), yttrium nitrate (Y(NO3)3), controlling ion concentrations: Co²⁺ 0.3mol / L, Mo 4 ⁺ 0.2 mol / L, Y³⁺ 0.05 mol / L; the mixture was added to the impregnation solution, stirred at 60℃ (180-220 rpm) and soaked for 4 h to ensure that the metal ions were uniformly loaded on the surface of the composite powder; after filtration, it was washed 3 times with deionized water and vacuum dried at 65℃ for 6 h to obtain the first powder; the process also included placing the first powder in a tube furnace, introducing a reducing atmosphere (N2:H2=8:2, volume ratio), heating at a rate of 8℃ / min, heating to 850℃ and holding for 5 h; and naturally cooling to room temperature to obtain the treated first powder (the precursor was reduced to Co and Mo elements, and Y was converted to Y₂O₃).

[0085] S3. Plasma Activation: The treated first powder is mixed with HEC powder (80-120nm) and Cr3C2 powder (50-80nm) at a mass ratio of 100:20:5, and placed in a plasma device with a vacuum degree of 10⁻. 4 Pa, argon flow rate 130 mL / min, 600℃ for 45 min to obtain the second powder;

[0086] S4. Add the second powder to a horizontal ball mill, using cemented carbide grinding balls (5mm diameter) at a ball-to-powder mass ratio of 13:1, and anhydrous ethanol as the medium (solid-to-liquid mass ratio 1:2). Mill at 380 rpm for 48 hours. After drying (vacuum drying at 55℃ for 5 hours), pass through a 140-mesh sieve to obtain a mixed powder. Plasma activation is used to enhance the surface energy of the powder, combined with high-energy ball milling to ensure uniform dispersion of each component. Load the mixed powder into a graphite mold (matching the drill bit size), apply a pressure of 220 MPa, and hold for 12 minutes to obtain a green body (density ≥68%).

[0087] S5. The green body is sintered using a three-stage heating process:

[0088] First stage (degreasing): Heat to 800℃ at 80℃ / min, hold at 30MPa for 4min, and remove residual impurities;

[0089] Second stage (pre-firing): Heat to 1250℃ at 100℃ / min, hold at 50MPa for 8min, and initially densify;

[0090] The third stage (densification): heating to 1750℃ at 110℃ / min and holding at 65MPa for 12min to achieve complete particle bonding;

[0091] After sintering, the product is cooled in the furnace (15℃ / min before 800℃, 8℃ / min from 800℃ to 300℃, and then naturally cooled after 300℃) to obtain the finished product. Example 6

[0092] This embodiment proposes a wear-resistant metal-ceramic composite material for blast furnace opening drills, which is prepared by the following steps:

[0093] S1. Mix WC powder (100-150nm) and ZrC powder (30-50nm) at a mass ratio of 4:1.5 to obtain a mixture.

[0094] S2. Preparation of impregnation solution: Using deionized water as solvent, dissolve cobalt nitrate (Co(NO3)2) and ammonium molybdate ((NH4)6Mo7O) 24 • 4H2O), yttrium nitrate (Y(NO3)3), controlling ion concentrations: Co²⁺ 0.4 mol / L, Mo 4 The mixture was prepared with 0.15 mol / L Y³⁺ and 0.03 mol / L Y³⁺. The mixture was added to the impregnation solution and stirred at 65°C (180 rpm) for 3 hours to ensure uniform loading of metal ions onto the surface of the composite powder. After filtration, it was washed twice with deionized water and vacuum dried at 60°C for 8 hours to obtain the first powder. The process also included placing the first powder in a tube furnace, introducing a reducing atmosphere (N₂:H₂ = 7:3, volume ratio), heating at a rate of 6°C / min, and holding at 800°C for 6 hours. The powder was then naturally cooled to room temperature to obtain the treated first powder (the precursor was reduced to Co and Mo, and Y was converted to Y₂O₃).

[0095] S3. Plasma Activation: The treated first powder is mixed with HEC powder (80-120nm) and Cr3C2 powder (50-80nm) at a mass ratio of 100:18:10, and placed in a plasma device with a vacuum degree of 10⁻. 4 Pa, argon flow rate 150 mL / min, 570℃ for 30 min to obtain the second powder;

[0096] S4. Add the second powder to a horizontal ball mill, using cemented carbide grinding balls (5mm diameter) at a ball-to-powder mass ratio of 15:1, and anhydrous ethanol as the medium (solid-to-liquid mass ratio 1:2.2). Mill at 420 rpm for 36 hours. After drying (vacuum drying at 55℃ for 4 hours), pass through a 140-mesh sieve to obtain a mixed powder. Plasma activation is used to increase the surface energy of the powder, combined with high-energy ball milling to ensure uniform dispersion of each component. Load the mixed powder into a graphite mold (matching the drill bit size), apply a pressure of 180 MPa, and hold for 18 minutes to obtain a green body (density ≥68%).

[0097] S5. The green body is sintered using a three-stage heating process:

[0098] First stage (degreasing): Heat to 900℃ at 100℃ / min, hold at 40MPa for 3min to remove residual impurities;

[0099] Second stage (pre-firing): Heat to 1300℃ at 120℃ / min, hold at 40MPa for 6min, and initially densify;

[0100] The third stage (densification): the temperature is increased to 1800℃ at 120℃ / min, and held at 70MPa for 10min to achieve complete particle bonding;

[0101] After sintering, the product is cooled in the furnace (15℃ / min before 800℃, 8℃ / min from 800℃ to 300℃, and then naturally cooled after 300℃) to obtain the finished product. Comparative Example 1

[0102] This comparative example proposes a wear-resistant metal-ceramic composite material for blast furnace opening drills. The preparation method differs from that of Example 5 in that, in step S1, ZrC powder is not included, and an equal amount of WC powder is used to replace ZrC powder. All other steps and process conditions are the same as in Example 5. Comparative Example 2

[0103] This comparative example proposes a wear-resistant metal-ceramic composite material for blast furnace opening drills. The preparation method differs from that of Example 5 in that, in step S2, the impregnation solution does not contain ammonium molybdate, and an equal amount of cobalt nitrate is used to replace ammonium molybdate. All other steps and process conditions are the same as in Example 5. Comparative Example 3

[0104] This comparative example presents a wear-resistant metal-ceramic composite material for blast furnace opening drills. The preparation method differs from that of Example 5 in that, in step S2, the impregnation solution does not contain yttrium nitrate, and an equal amount of ammonium molybdate replaces yttrium nitrate. All other steps and process conditions are the same as in Example 5. Comparative Example 4

[0105] This comparative example proposes a wear-resistant metal-ceramic composite material for blast furnace opening drills. The preparation method differs from that of Example 5 in that, in step S3, the first powder and HEC powder (80-120nm) are mixed at a mass ratio of 100:23, and Cr3C2 powder is not added. Other steps and process conditions are the same as in Example 5. Comparative Example 5

[0106] This comparative example proposes a wear-resistant metal-ceramic composite material for blast furnace opening drills. The preparation method differs from that of Example 5 in that, in step S5, the green billet is heated to 1800°C at 90°C / min and held at 60MPa for 25min. All other steps and process conditions are the same as in Example 5.

[0107] Related tests:

[0108] For the wear-resistant metal-ceramic composite materials prepared in Examples 1-6 and Comparative Examples 1-5, the following standard test methods were adopted to meet the core service requirements of blast furnace opening drills (high temperature resistance, high wear resistance, thermal shock resistance, and corrosion resistance):

[0109] (a) Basic mechanical property testing

[0110] room temperature hardness test

[0111] Basis: GB / T230.1-2018 "Metallic materials, Rockwell hardness test - Part 1: Test method";

[0112] Equipment: HR-150A Rockwell hardness tester;

[0113] Conditions: Test load 150 kgf (HRA scale), 5 different points are tested for each sample, and the average value is taken.

[0114] High temperature hardness test

[0115] Basis: Appendix A of GB / T230.1-2018 (High-Temperature Rockwell Hardness Test);

[0116] Equipment: HT-1000 high temperature hardness tester;

[0117] Conditions: Test temperature 1200℃, heat treatment for 30 min followed by loading, load 150kgf, 3 test points for each sample, calculate the high temperature hardness retention rate (high temperature hardness / room temperature hardness × 100%).

[0118] High temperature tensile strength test

[0119] High temperature (GB / T4338-2020 Metallic Materials - High Temperature Tensile Testing Method);

[0120] Equipment: GWT1150D high temperature tensile testing machine (1200℃);

[0121] Conditions: Hold at high temperature for 30 minutes before stretching, speed 1 mm / min, test each sample 3 times, and take the average value.

[0122] (II) Wear resistance and failure resistance test

[0123] Abrasion resistance test

[0124] Basis: GB / T12444.2-2019 "Metallic materials wear test methods - Part 2: Determination of wear amount and wear rate";

[0125] Equipment: MMW-1 Vertical Universal Friction and Wear Testing Machine;

[0126] Conditions: The grinding pair consists of GCr15 steel balls (hardness HRC62), load 50N, rotation speed 200r / min, and wear time 60min. The wear rate (wear mass / (load × sliding distance)) is calculated by weighing method (accuracy 0.1mg).

[0127] Thermal shock stability test

[0128] Basis: GB / T13298-2015 "Methods for Testing the Microstructure of Metallic Materials" (in conjunction with the determination of thermal cycling failure);

[0129] Equipment: SX2-12-16 high-temperature box furnace + ambient temperature cold water bath;

[0130] Conditions: The thermal cycling regime is "1200℃ holding for 30 min → room temperature cold water quenching". After each cycle, observe whether cracks appear on the sample surface and record the number of cycles when cracks first appear (thermal shock life). Each sample is tested 3 times.

[0131] (iii) Corrosion resistance test

[0132] Blast furnace slag corrosivity test

[0133] Simulated operating conditions: Blast furnace slag composition (mass fraction): FeO 35%, SiO2 25%, CaO 20%, Na2O 8%, Al2O3 12%, melting temperature 1450℃;

[0134] Equipment: MoSi2 high-temperature furnace + corundum crucible;

[0135] Conditions: Immerse the sample (10mm×10mm×5mm) in molten slag, keep it at that temperature for 2 hours, then remove it and cool it. Calculate the corrosion rate ((mass before corrosion - mass after corrosion) / mass before corrosion × 100%) by the weight loss method. Test each sample 3 times.

[0136] Table 1 Performance test results of wear-resistant metal-ceramic composite materials used in blast furnace opening drills in Examples 1-6

[0137] Performance indicators Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Room temperature hardness (HRA) 93.2 93.5 93.0 95.1 95.3 94.8 Hardness retention rate at 1200℃ (%) 88.3 89.3 88.0 91.7 92.1 91.5 Tensile strength at 1200℃ (MPa) 810 830 800 880 900 890 <![CDATA[Wear rate (×10⁻ 6 g / (N・m))]]> 3.0 2.8 3.1 2.1 1.9 2.2 Thermal shock life (number of cycles) 16 17 15 23 25 24 Slag corrosion rate (%) 0.031 0.028 0.033 0.020 0.018 0.019

[0138] Table 2 Performance test results of wear-resistant metal-ceramic composite materials for blast furnace opening drills in Comparative Examples 1-5

[0139] Performance indicators Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Room temperature hardness (HRA) 91.5 91.8 93.0 93.5 92.8 Hardness retention rate at 1200℃ (%) 82.5 75.3 86.2 88.5 85.0 Tensile strength at 1200℃ (MPa) 750 680 810 830 790 <![CDATA[Wear rate (×10⁻ 6 g / (N・m))]]> 3.8 4.5 3.2 3.0 3.5 Thermal shock life (number of cycles) 15 12 18 17 16 Slag corrosion rate (%) 0.035 0.042 0.028 0.040 0.025

[0140] As can be seen from Table 1, Examples 4-6, due to the addition of the "reduction calcination" step (reducing Co and Mo precursors to elemental forms and converting Y to Y2O3), exhibit significantly better performance than Examples 1-3—high-temperature tensile strength is significantly improved, wear rate is significantly reduced, and thermal shock life is also significantly increased; among them, Example 5 (Mo 4+ With a concentration of 0.2 mol / L and a reducing atmosphere of N2:H2=8:2, it exhibits the best overall performance, achieving a tensile strength of 900 MPa at 1200℃ and a slag corrosion rate of only 0.018%, meeting the requirements for 3000m 3 The above are the requirements for extra-large blast furnaces.

[0141] As can be seen from Table 2, in Comparative Example 1 (without ZrC): the absence of ZrC led to a sharp drop in high-temperature hardness and wear resistance, with a hardness retention rate of only 82.5% at 1200℃, proving the key role of ZrC in high-temperature stability.

[0142] Comparative Example 2 (without Mo): The absence of Mo intensifies the softening of the binder phase at high temperatures, with a tensile strength of only 680 MPa at 1200℃.

[0143] Comparative Example 3 (without Y): The absence of Y2O3 significantly reduced thermal shock lifetime.

[0144] Comparative Example 4 (without Cr3C2): The absence of Cr3C2 significantly reduced the resistance to slag corrosion, demonstrating the necessity of Cr3C2 for forming a dense protective film;

[0145] Comparative Example 5 (single-stage sintering): High-temperature tensile strength is significantly reduced.

[0146] Blast Furnace Field Application Test Results

[0147] A φ120mm blast furnace opening drill bit was prepared using materials from Example 5 and Comparative Example 2 (Mo-free). The bit was tested in a 2500m³ blast furnace (opening frequency once / day, taphole clay hardness 85HSD). The results are shown in Table 3 below.

[0148] Table 3

[0149] Application metrics Example 5 Drill Bit Comparative Example 2 Drill Bit Traditional WC-Co drill bits (commercially available) Time taken for a single opening (min) 8-10 12-15 10-13 Drill bit wear (mm / stroke) 0.3-0.5 0.8-1.2 0.6-0.9 Service life (number of openings) 28-32 8-10 9-12 Failure Mode Uniform wear Blade Break + Fracture Localized excessive wear

[0150] As can be seen from Table 3, the service life of the composite material drill bit in Example 5 is much longer than that of Comparative Example 2 and the traditional WC-Co drill bit, and the opening efficiency is improved by more than 20%, which can significantly reduce the operating costs of the blast furnace.

[0151] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for producing a wear-resistant cermet composite material for a blast furnace open hole drill, characterized by, Includes the following steps: S1. Mix WC powder and ZrC powder at a mass ratio of 4:(1-1.5) to obtain a mixture. S2, soaking the mixture at 55-65°C in an impregnation solution, and then filtering to obtain a first powder; the impregnation solution comprising Co 2+ , Mo 4+ , and Y 3+ ; S3. Mix the first powder, HEC powder and Cr3C2 powder, place them in a plasma device, and process them at 550-600°C under an inert gas atmosphere to obtain the second powder. S4. The second powder, grinding balls, and media are mixed and ball-milled to obtain a mixed powder; the mixed powder is loaded into a mold, pressure is applied, and pressure is maintained to obtain a green body; S5. The green blank is heated to 800-900℃ and held at 30-40MPa. Then the temperature is further increased to 1200-1300℃ and held at 40-50MPa. Then the temperature is further increased to 1750-1800℃ and held at 60-70MPa. After sintering, it is cooled in the furnace to obtain the wear-resistant metal-ceramic composite material. Before step S3, the process further includes placing the first powder in a tube furnace, introducing a reducing atmosphere, heating it to 780-850°C, and then holding it at that temperature. The HEC powder is prepared by the following steps: using anhydrous ethanol as solvent and tungsten carbide balls as the ball milling medium, nano-sized TiC (99.6 wt.% purity, 50 nm particle size), ZrC (99.7 wt.% purity, 50 nm particle size), NbC (99.5 wt.% purity, 80 nm particle size), HfC (99.7 wt.% purity, 90 nm particle size), and TaC (90 nm particle size) powders are mixed in a molar ratio of 1:1:1:1:1, and the mixture is ball-milled at 200 r / min for 10 h. After drying and sieving, a carbide mixed powder is obtained. In step S2, the concentration of Co2+ in the impregnation solution is 0.3-0.5 mol / L, the concentration of Mo 4 + is 0.1-0.2 mol / L, and the concentration of Y3+ is 0.03-0.05 mol / L. In step S3, the first powder, HEC powder and Cr3C2 powder are mixed in a mass ratio of 100:(15-20):(5-10).

2. The method of claim 1, wherein the wear resistant cermet composite material for a blast hole opener tool is characterized by, The reducing atmosphere is a mixture of nitrogen and hydrogen, with a volume ratio of nitrogen to hydrogen of (7-8):(2-3).

3. The method of claim 1, wherein the wear resistant cermet composite material for a blast hole opener tool is characterized by, In step S4, the medium is anhydrous ethanol, and the mass ratio of the powder balls is (12-15):1; the solid-liquid mass ratio of the second powder and the medium is 1:(2-2.5).

4. The method of claim 1, wherein the wear resistant cermet composite for a blast hole opener tool is characterized by, In step S4, a pressure of 180-220 MPa is applied and held for 12-18 minutes to obtain the green blank.

5. The method of claim 1, wherein the wear resistant cermet composite material for a blast hole opener tool is characterized by, In step S3, the flow rate of the inert gas is 120-150 mL / min; and / or, the treatment is carried out at 550-600 °C for 30-45 min.

6. The method of claim 1, wherein the wear resistant cermet composite for a blast hole drill is prepared by the steps of: In step S5, the temperature is raised to 800-900℃ and held at 30-40MPa for 3-5 minutes, and / or the temperature is raised to 1200-1300℃ and held at 40-50MPa for 5-8 minutes; and / or the temperature is raised to 1750-1800℃ and held at 60-70MPa for 10-15 minutes.

7. A wear resistant cermet composite material for a blast hole drill bit, characterized in that, It is prepared by the preparation method according to any one of claims 1-6.