Preparation method of high-toughness steel bond hard alloy composite material

Abstract

The invention discloses a preparation method of a high-toughness steel bond hard alloy composite material, and belongs to the technical field of hard alloy composite material processing. Performing grinding; performing surface treatment; carrying out layered blank making; performing vacuum packaging; performing hot rolling densification; sintering and strengthening; according to the preparation method, the layered composite material with high hardness and high impact toughness is successfully prepared through a set of complete'pretreatment-assembly-hot rolling-sintering 'synergistic process sequence; the core innovation point of the method is as follows: high-temperature hot rolling is performed in a green body state in which powder is not sintered, and power is provided for subsequent sintering by utilizing a mechanical activation effect, so that high-density and firm interface metallurgical bonding is realized at a relatively low sintering temperature within a relatively short heat preservation time; the contradiction that compactness and grain size as well as interface strength and toughness are difficult to consider in a traditional method is effectively solved.

Description

Technical Field

[0001] This invention belongs to the field of cemented carbide composite material processing technology, specifically a method for preparing high-toughness steel-structured cemented carbide composite materials. Background Technology

[0002] Steel-bonded cemented carbide, as a key material for composites of hard phase particles and steel matrix, is indispensable in machining, mining, and other fields due to its combination of high hardness, wear resistance, and toughness. Among them, TiC-based steel-bonded cemented carbide, with its high melting point and chemical stability of TiC, has become an important direction for replacing traditional WC-based materials, offering significant advantages in reducing costs and dependence on tungsten resources. However, existing technologies have multiple shortcomings: In terms of performance, although steel-bonded cemented carbide has high overall hardness, under extreme conditions such as high-speed and heavy-load cutting, the interface between the hard phase particles and the steel matrix is ​​prone to microcracks due to stress concentration, leading to premature wear and spalling of the material and significantly reducing its service life. At the same time, its room temperature toughness is still insufficient compared to pure steel materials. When faced with impact loads, cracks can easily propagate rapidly, leading to brittle fracture, which limits its application in scenarios with frequent impacts.

[0003] In terms of manufacturing processes, mainstream methods such as powder metallurgy and melt infiltration generally face the challenge of poor wettability between the hard phase (TiC) and the steel matrix when preparing steel-bonded cemented carbides. To improve wettability, precious metals such as nickel and molybdenum are often added, which not only increases raw material costs but may also introduce brittle phases, adversely affecting the material's toughness. Furthermore, conventional sintering processes (such as solid-state sintering or liquid-state sintering) typically require high sintering temperatures or long holding times to achieve high density, which can easily lead to abnormal coarsening of the hard phase grains, impairing the material's hardness and strength. Although post-sintering treatments such as hot rolling and hot isostatic pressing can improve density and microstructure, this "sintering first, then deformation" process route is difficult to process in sintered bodies with an already formed brittle ceramic network, prone to cracking, and has limited effect on grain refinement, making it difficult to achieve a balance between high density and fine-grained microstructure. Some technologies have attempted to improve toughness by preparing layered composite materials, but simple physical stacking followed by sintering often fails to achieve effective load transfer due to insufficient interface purification and low bonding strength, and the interface remains a rapid channel for crack propagation. From an economic and environmental perspective, the use of precious metal additives and energy-intensive sintering equipment (imported sintering furnaces cost over ten million yuan) significantly increases production costs, hindering large-scale application. Meanwhile, the shortcomings of existing materials in terms of high-temperature mechanical properties and corrosion resistance make it difficult to meet the demands of high-end manufacturing for long-life, low-wear tools.

[0004] Therefore, existing technologies lack a solution for economically and efficiently preparing steel-bonded cemented carbide composite materials that possess excellent hardness, high impact toughness, and strong interfacial bonding. This invention aims to overcome these shortcomings and provide a novel method for material structure design and preparation. Summary of the Invention

[0005] To address the above problems, this invention provides a method for preparing a high-toughness steel-bonded cemented carbide composite material. The method produces a steel-bonded cemented carbide composite material with low cost, high wear resistance, high toughness, and excellent interfacial bonding.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for preparing a high-toughness steel-structured cemented carbide composite material includes the following steps: Step S1, Ingredients: Weigh the hard phase powder and manganese steel powder raw materials according to the weight percentage; the hard alloy composite powder is composed of hard phase and manganese steel matrix powder, and the manganese steel powder contains rare earth elements accounting for 0.05%-0.5% of its mass; Step S2, Grinding: The hard phase powder and manganese steel powder raw materials are mixed and introduced into a rolling ball mill for dry grinding and wet grinding to make the raw material powders uniformly mixed. Finally, the powder is dried to obtain hard alloy composite powder. Step S3, Surface treatment: Clean the outer surface of the alloy steel plate to remove surface impurities, oil and dust; Step S4, Layered billet preparation: The cleaned alloy steel plate and the hard alloy composite powder obtained in step S2 are alternately stacked and filled in a cassette to form a layered billet. The filled billet is vibrated to compact it, and then cold-pressed and shaped under a pressure of 100MPa-300MPa. Step S5, Vacuum sealing: Heat the cold-pressed box while drawing a vacuum. When the temperature rises to 100℃-400℃ and the internal absolute pressure does not exceed 500Pa, weld the box to seal it. Step S6, Hot Rolling Densification: The vacuum-sealed billet is introduced into a sintering furnace and heated to 1000℃-1250℃ and held for 1-4 hours. Then it is immediately sent to a hot rolling mill for rapid rolling, and the hot rolling deformation is controlled at 20%-70%. Step S7, Sintering Strengthening: The hot-rolled billet is reintroduced into the sintering furnace for sintering to obtain a steel-bonded hard alloy composite material.

[0007] In the above technical solution, steps S1-S2, through the addition of rare earth elements and uniform mixing, provide the material with the potential for fine graining and interface purification; steps S3-S5, with layered billet assembly and vacuum encapsulation, construct a composite structure and prevent high-temperature oxidation; step S6, hot rolling densification, is a key technology: the green billet is rolled with a large deformation at 1000℃-1250℃, and the powder particles undergo plastic deformation and rearrangement under pressure and temperature, which greatly increases the density of the billet; at the same time, the rolling force breaks the oxide film on the powder surface, exposing the fresh, highly active metal surface, and tightly bonding it with the alloy steel plate surface under high pressure, creating ideal conditions for subsequent atomic diffusion and metallurgical bonding; step S7, sintering, on the basis of this activation, ultimately achieves complete metallurgical bonding and structural stabilization through atomic diffusion and mass migration.

[0008] In a preferred embodiment, the hard phase powder is TiC or WC, with a weight percentage of 40%-80%, and the manganese steel powder has a weight percentage of 20%-60%. In this technical solution, the hard phase is the main contributor to the material's hardness and wear resistance. When its content is below 40%, the overall hardness and wear resistance of the material are insufficient; when its content is above 80%, the material becomes too brittle and its impact toughness drops sharply. The manganese steel matrix acts as a binder phase, encapsulating and fixing the hard phase particles, and its content ensures the material's toughness and strength. Within this ratio range, the two can form a continuous network structure, fully leveraging their respective performance advantages.

[0009] In a preferred embodiment, the rare earth element is one or more of yttrium, lanthanum, and cerium. In this technical solution, rare earth elements such as yttrium (Y), lanthanum (La), and cerium (Ce) have high chemical reactivity. During sintering, they preferentially react with impurities such as oxygen and sulfur on the surface of powder particles and in the matrix, generating stable compounds with high melting points. This "purifies" the surface of the molten metal and powder, greatly improving the wettability of the manganese steel matrix to hard phases (especially poorly wettable TiC). Simultaneously, the rare earth elements segregate at grain boundaries and phase boundaries, effectively inhibiting grain growth and the formation and coarsening of brittle carbide phases during sintering, thus playing a role in grain refinement and interface optimization.

[0010] In a preferred embodiment, the alloy steel plate is high-manganese steel or NM series wear-resistant steel. In this technical solution, high-manganese steel undergoes significant work hardening under severe impact or pressure, resulting in a sharp increase in surface hardness and extreme wear resistance, while the core retains excellent toughness. NM series wear-resistant steel itself possesses high strength and good toughness. Using these as a composite layer, when the material is impacted, the alloy steel plate layer absorbs and disperses impact energy through its own plastic deformation, preventing cracks from propagating to the hard and brittle cemented carbide layer, or deflecting and passivating cracks that have extended to the interface.

[0011] In a preferred embodiment, in step S4, the thickness ratio of the cemented carbide composite powder layer to the alloy steel plate layer is 10-1:1. In this technical solution, when the cemented carbide layer is too thick (ratio > 10:1), the material as a whole tends to be brittle and prone to penetrating fracture under impact; when the steel plate layer is too thick (ratio < 1:1), the overall hardness and wear resistance of the material will significantly decrease. Within a ratio range of 10:1 to 1:1, the hard cemented carbide layer undertakes the main wear resistance task, while the tough alloy steel plate layer serves as a support and toughening unit. This ratio ensures that under load, the tough layer has sufficient volume for plastic deformation and energy absorption, while the cemented carbide layer has sufficient thickness to provide a long wear life.

[0012] In a preferred embodiment, in step S4, the casing material is low alloy steel or stainless steel.

[0013] In a preferred embodiment, after sintering in step S7, the process further includes step S8, secondary hot rolling and heat treatment: the sintered composite material is held at 1000℃-1150℃ for 0.5-1h, and then subjected to secondary hot rolling with a deformation of 10%-40%. It is then returned to the sintering furnace for furnace cooling to below 1000℃ before being unloaded. This technical solution involves secondary hot rolling (10%-40% deformation) after sintering, applying plastic deformation to the sintered composite material. This breaks down coarse grains, refining them (fine grain strengthening), and simultaneously compressing any residual micropores that may exist within the material. The subsequent heat treatment (furnace cooling) is an annealing process designed to eliminate processing stress and lattice distortion introduced by the secondary rolling, stabilizing the microstructure, restoring some plasticity and toughness, and preventing material embrittlement.

[0014] In a preferred embodiment, the sintering temperature in step S7 is 1200℃-1400℃.

[0015] A high-toughness steel-bonded cemented carbide composite material is disclosed, comprising alternating layers of cemented carbide and alloy steel plates, with metallurgical bonding between the layers. The hardness of the cemented carbide layer is not less than 85 HRA, and the composite material exhibits an impact energy of not less than 25 J in a Charpy V-notch impact test, with the impact fracture surface showing significant deflection and passivation of the crack as it propagates to the interlayer interface. The structure of this composite material consists of alternating layers of cemented carbide (providing hardness and wear resistance) and alloy steel plates (providing toughness) bonded by metallurgical bonding (rather than simple mechanical bonding). When a crack initiates from the hard and brittle cemented carbide layer and propagates to the interface, due to the obstruction of the tough steel plates and the high interfacial bonding strength, the crack cannot penetrate directly but is forced to change direction, propagating along the interface or into the steel plates. This "deflection and passivation" process consumes a large amount of energy, macroscopically manifested as a significant increase in impact energy (not less than 25 J), thus achieving a balance between high hardness and high impact toughness.

[0016] In a preferred embodiment, the overall density of the composite material is not less than 99.5%, and the average grain size of the hard phase is not greater than 2.0 μm. High density (≥99.5%) means that there are very few defects such as pores and voids inside the material, which allows the load to be transmitted evenly, avoids stress concentration, and thus improves the actual strength, toughness and fatigue life of the material; the fine hard phase grains (≤2.0 μm) follow the Hall-Page relation of "fine grain strengthening", that is, the finer the grains, the higher the strength and toughness of the material.

[0017] Compared with the prior art, the technical effects of the present invention are: (1) The present invention successfully prepared a layered composite material with both high hardness and high impact toughness through a complete set of "pretreatment-component assembly-hot rolling-sintering" synergistic process sequence; the core innovation of this method is to carry out high-temperature hot rolling in the "green" state of the powder before sintering, and use the mechanical activation effect to provide power for subsequent sintering, thereby achieving high densification and strong interface metallurgical bonding at a relatively low sintering temperature and a short holding time, effectively solving the contradiction between density and grain size, interface strength and toughness in the traditional method; This invention significantly improves the microstructure of composite materials by adding specific rare earth elements, particularly strengthening the interface between the cemented carbide layer and the alloy steel plate, thereby enhancing the overall mechanical properties of the material, especially its impact toughness. The selection of a specific alloy steel plate that complements and synergizes with the cemented carbide layer in terms of performance ensures that the tough layer effectively absorbs energy when subjected to impact loads, protecting the cemented carbide layer from brittle fracture. By controlling the thickness ratio of the cemented carbide powder layer to the alloy steel plate layer, the stress distribution within the composite material is optimized, achieving the best balance between hardness / wear resistance and impact toughness. This ensures effective load transfer between layers and prevents overall performance degradation due to premature failure of any single layer. This invention, through secondary hot rolling and heat treatment after sintering, can further eliminate residual stress inside the composite material, refine grains, and close microscopic defects, thereby slightly improving the density, strength, and toughness of the material and stabilizing product performance; it also determines the optimal sintering temperature window to ensure that the material can achieve sufficient atomic diffusion and metallurgical bonding, reaching a near-fully dense state, while avoiding over-burning, excessive grain growth, or the generation of unfavorable liquid phases. This invention clearly defines the superior performance indicators and structural characteristics of the composite material obtained by this method. The product directly reflects the technical effect of the invention method, namely, successfully obtaining a unique layered composite material with excellent hardness and toughness and crack deflection ability. The high quality of the composite material is further defined by quantitative microscopic indicators (density ≥99.5%, grain size ≤2.0μm), indicating that the material has very few internal defects and a uniform and fine structure, which is the fundamental guarantee for its excellent macroscopic mechanical properties. Attached Figure Description

[0018] Figure 1 This is a structural diagram of the steel-structured cemented carbide composite material billet obtained in Example 1.

[0019] Figure 2 This is a structural diagram of the steel-structured cemented carbide composite material billet obtained in Example 2. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solution, the present invention will be described in detail below with reference to embodiments. The description in this part is only exemplary and explanatory, and should not be used to limit the scope of protection of the present invention in any way.

[0021] Example 1: A method for preparing a high-toughness steel-bonded cemented carbide composite material, comprising the following steps: Step S1, Ingredients: Weigh TiC powder (50% by weight) with an average particle size of 1.5 μm and high manganese steel powder (Fe-Mn-C alloy, 50% by weight) containing 0.1% cerium. Step S2, Grinding: After mixing the above powder, it is fed into a rolling ball mill and wet-milled with alcohol as the medium for 48 hours. Then it is dried in a vacuum drying oven at 80°C and passed through a 100-mesh sieve to obtain cemented carbide composite powder. Step S3, Surface treatment: Cut the 1mm thick Mn13 high manganese steel plate into the specified size, sandblast its surface, and ultrasonically clean it with acetone to remove oil and oxide layer; Step S4, Layered blank preparation: First, lay a clean Mn13 steel plate at the bottom of the cladding box (material is 304 stainless steel), then lay a layer of hard alloy composite powder obtained in step S2 (control the thickness to 4mm), and so on, layering alternately, for a total of 10 layers (5 layers of steel plate + 5 layers of powder), vibrate on the vibrating table for 10 minutes, and then cold press and hold at 200MPa pressure for 30 minutes; Step S5, Vacuum sealing: Transfer the cold-pressed enclosure into a vacuum furnace, heat it to 250°C at 10°C / min, and simultaneously evacuate the system until the vacuum level reaches 50Pa. Then, seal the enclosure by argon arc welding. Step S6, Hot Rolling Densification: The sealed billet is placed in a sintering furnace and heated to 1150°C at a rate of 10°C / min, held for 3 hours, and then quickly transferred to a hot rolling mill for single-pass rolling at 1150°C, with a hot rolling deformation of 40%. Step S7, Sintering Strengthening: The hot-rolled billet is quickly transferred back to the sintering furnace, heated to 1300℃ at 5℃ / min, held for 3 hours, and then cooled in the furnace. Step S8, Secondary Hot Rolling and Heat Treatment: The composite material obtained by sintering is cooled to 1150℃ in the furnace, held for 0.5h, and then subjected to secondary hot rolling with a deformation of 10%. It is then returned to the sintering furnace and cooled to below 1000℃ before being taken out of the furnace to obtain the final steel-bonded cemented carbide composite material.

[0022] Example 2: A method for preparing a high-toughness steel-structured cemented carbide composite material, comprising the following steps: Step S1, Ingredients: Weigh WC powder (65% by weight) with an average particle size of 2.0 μm and high manganese steel powder (Fe-Mn-C alloy, 35% by weight) containing 0.08% yttrium. Step S2, Grinding: After mixing the above powder, it is fed into a rolling ball mill and wet-milled with alcohol as the medium for 48 hours. Then it is dried in a vacuum drying oven at 80°C and passed through a 100-mesh sieve to obtain cemented carbide composite powder. Step S3, Surface treatment: Cut the 1.5mm thick NM600 wear-resistant steel plate into the specified size, sandblast its surface, and ultrasonically clean it with acetone to remove oil and oxide layer; Step S4, Layered blank preparation: First, lay a clean NM600 wear-resistant steel plate (1.5mm thick) at the bottom of the casing box (material is 304 stainless steel), then lay a layer of hard alloy composite powder obtained in step S2 (control the thickness to 9mm), and so on, layering alternately, for a total of 8 layers (4 layers of steel plate + 4 layers of powder), vibrate on the vibrating table for 15 minutes, and then cold press and hold at 220MPa pressure for 30 minutes; Step S5, Vacuum sealing: Transfer the cold-pressed enclosure into a vacuum furnace, heat it to 270°C at 10°C / min, and simultaneously evacuate the system until the vacuum level reaches 500Pa. Then, seal the enclosure by argon arc welding. Step S6, Hot Rolling Densification: The sealed billet is placed in a sintering furnace and heated to 1180°C at a rate of 10°C / min, held for 2.5 hours, and then quickly transferred to a hot rolling mill for single-pass rolling at 1180°C, with a hot rolling deformation of 35%. Step S7, Sintering Strengthening: The hot-rolled billet is quickly transferred back to the sintering furnace, heated to 1300℃ at 5℃ / min, held for 2 hours, and then cooled in the furnace. Step S8, Secondary Hot Rolling and Heat Treatment: The composite material obtained by sintering is cooled to 1080℃ in the furnace, held for 0.5h, and then subjected to secondary hot rolling with a deformation of 15%. It is then returned to the sintering furnace and cooled to below 1000℃ before being taken out of the furnace to obtain the final steel-bonded cemented carbide composite material.

[0023] Example 3: A method for preparing a high-toughness steel-bonded cemented carbide composite material, comprising the following steps: Step S1, Ingredients: Weigh TiC powder (70% by weight) with an average particle size of 1.5 μm and high manganese steel powder (Fe-Mn-C alloy, 30% by weight) containing 0.15% lanthanum. Step S2, Grinding: After mixing the above powder, it is fed into a rolling ball mill and wet-milled with alcohol as the medium for 48 hours. Then it is dried in a vacuum drying oven at 80°C and passed through a 100-mesh sieve to obtain cemented carbide composite powder. Step S3, Surface treatment: Cut the 2mm thick Mn13 high manganese steel plate into the specified size, sandblast its surface, and ultrasonically clean it with acetone to remove oil and oxide layer; Step S4, Layered blank preparation: First, lay a clean Mn13 steel plate at the bottom of the cladding box (material is 304 stainless steel), then lay a layer of hard alloy composite powder obtained in step S2 (control the thickness to 2mm), and so on, layering alternately, for a total of 10 layers (5 layers of steel plate + 5 layers of powder), vibrate on the vibrating table for 10 minutes, and then cold press and hold at 150MPa pressure for 40 minutes; Step S5, Vacuum sealing: Transfer the cold-pressed box into a vacuum furnace, heat it to 350°C at 10°C / min, and simultaneously evacuate the system until the vacuum degree reaches 50Pa, then seal the box with argon arc welding. Step S6, Hot Rolling Densification: The sealed billet is placed in a sintering furnace and heated to 1200℃ at a rate of 10℃ / min, held for 2 hours, and then quickly transferred to a hot rolling mill for single-pass rolling at 1200℃, with a hot rolling deformation of 38%. Step S7, Sintering Strengthening: The hot-rolled billet is quickly transferred back to the sintering furnace, heated to 1270℃ at 5℃ / min, held for 1 hour, and then cooled in the furnace. Step S8, Secondary Hot Rolling and Heat Treatment: The composite material obtained by sintering is cooled to 1080℃ in the furnace and held for 0.5h. Then, it is subjected to secondary hot rolling with a deformation of 15%. After that, it is returned to the sintering furnace and cooled to below 1000℃ in the furnace to obtain the final steel-bonded cemented carbide composite material.

[0024] Comparative Example 1: The main difference between this comparative example and Example 1 is that the addition of rare earth elements is omitted. In step S1, TiC powder (50%) and the same high manganese steel powder (50%) without rare earth elements are weighed. The remaining steps are the same as in Example 1.

[0025] Comparative Example 2: The main difference between this comparative example and Example 1 is that the process sequence has been adjusted, with the order of "hot rolling densification" and "sintering strengthening" reversed; that is, sintering is performed first (1300℃ / 3h), and then the sintered billet is hot rolled (1150℃ / 40% deformation). The remaining steps are the same as in Example 1.

[0026] Comparative Example 3: The main difference between this comparative example and Example 1 is that it uses a traditional homogeneous material structure instead of a layered composite. In step S4, the mixed cemented carbide composite powder is directly loaded into the casing, vibrated, and cold-pressed, without adding any alloy steel plate layer in between; the remaining steps are the same as in Example 1.

[0027] Comparative Example 4: The main difference between this comparative example and Example 1 is that after layered preform preparation, hot rolling is not performed; sintering is carried out directly. After vacuum sealing, the preform does not undergo a hot rolling densification step but is directly sintered for strengthening (1300℃ / 3h). The remaining steps are the same as in Example 1.

[0028] The steel-bonded cemented carbide composite materials obtained in Examples 1-3 and Comparative Examples 1-4 were subjected to performance tests. For example, hardness testing was conducted using the Rockwell A scale according to standard GB / T 3849.1-2015 "Hard Alloy Rockwell Hardness Test (A Scale)"; impact toughness testing was conducted using the Charpy V-notch impact test according to standard GB / T 229-2020 "Charpy Pendulum Impact Test Method for Metallic Materials"; density testing was conducted using the Archimedes displacement method according to standard GB / T 3850-2015 "Dense Sintered Metallic Materials and Hard Alloys Density Determination Method"; average grain size of the hard phase was determined using metallographic microscopy according to standard GB / T3488.3-2021 "Metallographic Determination of Microstructure of Hard Alloys"; and interface bonding analysis was performed using scanning electron microscopy and energy dispersive spectroscopy. The test results are shown in the table below.

[0029]

[0030] It should be noted that, in this document, the terms "comprising," "including," and any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Specific examples have been used in this document to illustrate the principles and implementation methods of the present invention. These examples are merely for the purpose of helping to understand the method and core ideas of the present invention. The above descriptions are only preferred embodiments of the present invention. It should be pointed out that, due to the limitations of written expression and the objective existence of infinite specific structures, those skilled in the art can make several improvements, modifications, or variations without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, variations, or combinations, or the direct application of the concept and technical solution of the present invention to other situations without modification, should all be considered within the scope of protection of the present invention.

Claims

1. A method of producing a high toughness steel-cemented carbide composite material, characterized in that, The method comprises the following steps: Step S1, batching: hard phase powder and manganese steel powder raw materials are weighed according to percentage by weight; the hard alloy composite powder is composed of hard phase and manganese steel matrix powder, and the manganese steel powder contains 0.05%-0.5% of rare earth elements by mass; Step S2, grinding: the hard phase powder and the manganese steel powder raw materials are mixed and introduced into a rolling ball mill for dry grinding and wet grinding treatment, so that the raw material powder is uniformly mixed, and finally dried to obtain the hard alloy composite powder; Step S3, surface treatment: the outer surface of the alloy steel plate is cleaned to remove surface impurities, oil stains and dust; Step S4, layered billet making: the cleaned alloy steel plate and the hard alloy composite powder obtained in step S2 are alternately stacked in a jacket box to form a layered billet, and the stacked billet is vibrated and compacted, and then cold pressed and shaped under a pressure of 100-300 MPa; Step S5, vacuum packaging: the jacket box after cold pressing is heated while being vacuumized, and when the temperature rises to 100-400℃ and the internal absolute pressure is not higher than 500 Pa, the jacket box is welded and sealed; Step S6, hot rolling densification: the billet after vacuum packaging is introduced into a sintering furnace and heated to 1000-1250℃ and kept for 1-4 h, and then immediately sent to a hot rolling mill for rapid rolling, and the hot rolling deformation amount is controlled to be 20%-70%; Step S7, sintering strengthening: the billet after hot rolling is introduced into a sintering furnace again for sintering to obtain a steel-bonded hard alloy composite material.

2. The production method according to claim 1, characterized by, The hard phase powder is TiC or WC, and the percentage by weight is 40%-80%, and the percentage by weight of the manganese steel powder is 20%-60%.

3. The production method according to claim 1, characterized by, The rare earth elements are one or more of yttrium, lanthanum and cerium.

4. The method of claim 1, wherein, The alloy steel plate is high manganese steel or NM series wear-resistant steel.

5. The preparation method according to claim 1, characterized in that, In step S4, the thickness ratio of the hard alloy composite powder layer to the alloy steel plate layer is 10-1:

1.

6. The method of claim 1, wherein, In step S4, the material of the jacket box is low alloy steel or stainless steel.

7. The preparation method according to claim 1, characterized in that, After step S7, a step S8, secondary hot rolling and heat treatment, is further included: the sintered composite material is kept at 1000-1150℃ for 0.5-1 h, and then subjected to secondary hot rolling with a deformation amount of 10%-40%, and then returned to the sintering furnace for furnace cooling to below 1000℃ and discharged.

8. The method of claim 1, wherein, In step S7, the sintering temperature condition is 1200-1400℃.

9. A high toughness steel-bonded carbide composite material produced by the method of any one of claims 1-8, characterized in that, The composite material is composed of hard alloy layers and alloy steel plate layers alternately stacked, and the layers are metallurgically bonded; the hardness of the hard alloy layer is not less than 85 HRA, the impact energy of the composite material in the Charpy V-notch impact test is not less than 25 J, and the impact fracture shows that the crack is obviously deflected and passivated when it expands to the layer interface.

10. The composite material of claim 9, wherein, The overall density of the composite material is not less than 99.5%, and the average grain size of the hard phase is not greater than 2.0 μm.

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