A method for in-situ refining wear-resistant high alloy steel iron carbide and application thereof

Abstract

This invention belongs to the field of powder metallurgy technology and relates to a method for in-situ refining wear-resistant high-alloy steel carbides and its application. The method includes the following steps: selecting raw materials with low intrinsic thermal conductivity, good bending strength, and lightweight potential; preheating and homogenizing the raw materials; and pressure forming followed by slow cooling. This invention significantly solves the inherent problem of coarse carbide growth in high-alloy steel by introducing novel multi-element substitution phases, resulting in a significant Zener pinning effect; and exhibits excellent and uniform interface bonding with the original carbides and matrix in the high-alloy steel. This invention, combining a specific pressure forming process and a small amount of additive phases, has a simple preparation process, and the resulting material exhibits outstanding high-temperature resistance, good density, excellent microhardness, strong crack resistance, oxidation resistance, and red hardness. It can be used as a wear-resistant mold at higher temperatures and has good application prospects in radiation-resistant environments.

Description

Technical Field

[0001] This invention belongs to the field of powder metallurgy technology, and relates to the preparation of wear-resistant high alloy steel, and particularly to a method for in-situ refining of wear-resistant high alloy steel carbides and its application. Background Technology

[0002] Wear-resistant high-alloy steel materials (such as white cast iron, high-manganese steel, and high-speed steel) are widely used in metallurgy and machinery manufacturing due to their excellent hardness and wear resistance. The wear resistance of these materials is highly dependent on the morphology, size, and distribution of carbides in their microstructure. However, how to balance the hardness and toughness of the material, i.e., effectively control the growth and coarsening of carbides, has always been a technical challenge in this field.

[0003] Currently, the industrial production of high-alloy steel materials mainly relies on casting and traditional heat treatment processes. While these methods have the advantages of low cost and mature technology, they are difficult to suppress carbide growth during solidification and cooling, easily forming coarse network or blocky eutectic carbides. This coarse microstructure severely disrupts the matrix, leading to a significant decrease in the material's mechanical properties, especially impact toughness, thereby shortening the service life of components.

[0004] To overcome the above-mentioned defects, researchers have tried various modification techniques, but each still has its limitations: 1. Modification with added reinforcing phases: For example, using ceramic particles such as zirconia-toughened alumina as reinforcing phases to strengthen high-chromium cast iron. However, since the ceramic particles and the metal matrix are usually only mechanically bonded, the interfacial bonding strength is insufficient. Under wear conditions, the reinforcing particles are prone to spalling, causing further abrasive wear (Reference 1, Wear 2019; 428-429: 167-177), which accelerates material failure. In addition, this method is not ideal in refining the primary carbides in the matrix, resulting in limited improvement in overall performance. 2. Metallurgical process control: For example, using electroslag remelting or electromagnetic stirring technology, although it can improve the solidification structure to a certain extent, it is still difficult to completely eliminate large-sized network eutectic carbides. Adding rare earth elements for modification treatment, although theoretically having a refining effect, has problems such as difficulty in accurately controlling the amount of rare earth added, poor distribution uniformity, and high cost, resulting in poor stability in industrial applications. Nitrogen alloying technology is limited by factors such as the difficulty of nitriding processes and the difficulty in controlling the nitrogen content, resulting in a limited effect on refining carbide and matrix grains. 3. Advanced manufacturing technologies: Processes such as additive manufacturing and laser remelting, which have been developed in recent years, still have inherent drawbacks such as high process difficulty and high cost. Furthermore, the formed parts are prone to metallurgical defects such as porosity and cracks, making it difficult to achieve full density. At the same time, under certain conditions, it is still impossible to completely eliminate the network eutectic carbide structure.

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

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for in-situ refining wear-resistant high-alloy steel carbides and its application.

[0007] To achieve the above objectives, the present invention provides the following technical solution: On the one hand, see Figure 1 This invention provides a method for in-situ refining of wear-resistant high-alloy steel carbides, specifically including the following steps: Step 1: Select high-alloy steel blocks and pyrochlore-structured high-entropy oxide / fluorite-structured high-entropy oxide powder as raw materials, and the mass ratio of the high-alloy steel blocks and pyrochlore-structured high-entropy oxide / fluorite-structured high-entropy oxide powder is 9:1~99:1; Step 2: First, heat the high alloy steel block, then quickly add pyrochlore structure high entropy oxide / fluorite structure high entropy oxide powder, stir evenly to obtain mixed powder, and then quickly pour the mixed powder onto the die forging machine, and preheat the die to 500℃~1100℃. Step 3: First, pressurize to 10MPa~200MPa in 10s~30s, hold the pressure for 150s~250s, then depressurize to atmospheric pressure in 10s~20s, then remove from the mold in 5s~30s, place in a heating furnace with a preheated temperature of 800℃~1000℃, keep warm for 4h~12h, control the vacuum degree at 0.01Pa~0.1Pa, then cool down to 460℃~780℃ at a rate of 1℃ / min~5℃ / min, and finally air cool to room temperature.

[0008] Specifically, the intrinsic thermal conductivity of the pyrochlore-structured high-entropy oxide / fluorite-structured high-entropy oxide powder is 0.9 W / (m·K)~1.7 W / (m·K), and the flexural strength is 100 MPa~800 MPa.

[0009] Furthermore, the preparation process of the pyrochlore-structured high-entropy oxide / fluorite-structured high-entropy oxide powder is as follows: Prepare materials according to the target product and mix them according to the atomic ratio of the target product. Then, heat the mixture to 1200℃~1600℃ at a rate of 1℃ / min~5℃ / min, sinter for 1h~6h, and grind and sieve.

[0010] Preferably, the fluorite-structured high-entropy oxide powder is (Ce 0.2 Zr 0.2 Ti 0.2 Sn 0.2 Hf 0.2 The pyrochlore-structured high-entropy oxide powder is Y2(ZrTiGeHfSnSi)2O7 powder or Y2(Zr 1 / 6 Ti1 / 3 Ge 1 / 6 Hf 1 / 12 Sn 1 / 4 )2O7 powder.

[0011] In the high-alloy steel block, the volume fraction of M7C3 is 18%~30%, and the size is 10μm~500μm; the volume fraction of MC is 1.1%~3.5%, and the size is 0.5μm~5μm; (Cr,Mo,W) 23 The volume fraction of C6 is 0.5% to 1.5%, and the size is 0.2 μm to 2 μm.

[0012] The size of the pyrochlore-structured high-entropy oxide / fluorite-structured high-entropy oxide powder is 20μm~150μm.

[0013] Specifically, in step 2, the time taken to add the pyrochlore-structured high-entropy oxide / fluorite-structured high-entropy oxide powder is 2s~12s, and the time taken to pour the mixed powder onto the forging machine is 2s~8s.

[0014] Furthermore, step 2 specifically includes: The high-alloy steel block is heated in an induction heating furnace to 1400℃~1600℃ at a rate of 100℃ / s~300℃ / s, with a vacuum degree of 0.1Pa~1.1Pa, and held for 5s~15s. Powdered pyrochlore-structured high-entropy oxide / fluorite-structured high-entropy oxide is added over a period of 2s~12s, while stirring at a rate of 1r / s~3r / s for 10s~20s to obtain a mixed powder. The mixed powder is then poured into a die forging machine over a period of 2s~8s, and the die is preheated to 500℃~1100℃.

[0015] On the other hand, the present invention also provides a wear-resistant high-alloy steel material prepared by some or all of the methods described above. The wear-resistant high-alloy steel material has excellent high-temperature resistance, good density, and excellent microhardness, specifically: red hardness of 50HRC~65HRC, density of 98.5%~99.9%, and microhardness of 6GPa~18GPa.

[0016] In addition, the present invention also provides an application of the wear-resistant high alloy steel material prepared by some or all of the above methods in high-speed cutting wear-resistant tools, with an application environment temperature of room temperature to 650°C.

[0017] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects: 1) This invention effectively shortens the high-temperature residence time and heating and holding time in the preparation process by introducing an improved multi-element substitution high-entropy ceramic. Then, by inhibiting the growth of carbides at the front end of the growth process, it significantly solves the problem of the inherent coarse growth of carbides in high alloy steel. The Zener pinning effect is better than the existing conventional process. 2) The novel multi-element substitution high-entropy ceramic introduced in this invention forms a directly connected metallurgical interface with the high-alloy steel matrix and the original carbides, exhibiting low interfacial energy and high bonding strength. This excellent interfacial bonding, combined with the good wettability of the high-entropy ceramic under the multi-element substitution design, results in a significantly better uniformity of its distribution in the matrix compared to traditional ceramic reinforcing phases. This effectively avoids agglomeration and interfacial debonding, providing a structural basis for improving the overall performance of the material. 3) This invention combines a specific pressure forming process with a small amount of additive phase. The process is simple, the material has excellent high temperature resistance (room temperature ~ 650℃), good density (density of 98.5% ~ 99.9%), and excellent microhardness (microhardness of 6GPa ~ 18GPa).

[0018] 4) The material prepared by this invention has strong anti-cracking ability, oxidation resistance and red hardness, and can be used as wear-resistant mold at higher temperatures. It has good application prospects in radiation-resistant environments. At the same time, the method provided by this invention has low preparation cost, significant improvement in structure and obvious performance enhancement, and can be mass-produced on a large scale. Attached Figure Description

[0019] The accompanying drawings are incorporated in and form part of this specification, and together with the description serve to explain the principles of the invention.

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A flowchart of the method for in-situ refining wear-resistant high-alloy steel carbides provided by the present invention; Figure 2 This is a scanning electron microscope image of the in-situ refined wear-resistant high-alloy steel prepared in Example 1 of the present invention after corrosion; Figure 3 Scanning electron microscope image of wear-resistant high-alloy steel without additive phase after corrosion, prepared in Comparative Example 1; Figure 4 The image is a scanning electron microscope image of the wear-resistant high-alloy steel without additive phase prepared in Comparative Example 2 after corrosion. Figure 5This is a scanning electron microscope image of the in-situ refined wear-resistant high-alloy steel prepared in Example 2 of the present invention after corrosion; Figure 6 This is a scanning electron microscope image of the in-situ refined wear-resistant high-alloy steel prepared in Example 3 of the present invention after corrosion; Figure 7 This is a scanning electron microscope image of the in-situ refined wear-resistant high-alloy steel prepared in Example 4 of the present invention after corrosion. Detailed Implementation

[0022] Exemplary embodiments will now be described in detail. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples consistent with some aspects of the invention as detailed in the appended claims.

[0023] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0024] Example 1 This embodiment provides a method for in-situ refining carbides in wear-resistant high-alloy steel, specifically including the following steps: Step 1: Select high-alloy steel blocks and fluorite-structured high-entropy oxide powder as raw materials, and the mass ratio of the high-alloy steel blocks and fluorite-structured high-entropy oxide powder is 9:1; Among them, the high-entropy oxide powder with fluorite structure is selected from (Ce 0.2 Zr 0.2 Ti 0.2 Sn 0.2 Hf 0.2 O2 powder with a size of 20 μm; the high-alloy steel bulk material comprises, by weight percentage: 18% Cr, 0.90% Mo, 2.10% V, 0.50% Si, 1.00% Nb, 0.20% Mn, and 0.40% W; in the high-alloy steel bulk material, the volume fraction of M7C3 is 18% with a size of 10 μm, and the volume fraction of MC is 1.1% with a size of 0.5 μm, (Cr, Mo, W) 23 C6 has a volume fraction of 0.5% and a size of 0.2 μm.

[0025] Step 2: First, heat the high-alloy steel block, then quickly add (Ce) 0.2 Zr 0.2 Ti 0.2 Sn 0.2 Hf 0.2 O2 powder is stirred evenly to obtain a mixed powder, which is then quickly poured onto a forging machine, with the mold preheated to 500°C. The specific steps of this process are as follows: High-alloy steel blocks were heated in an induction furnace at a rate of 100℃ / s to 1400℃, with a vacuum of 0.1 Pa, held for 5 seconds, and then rapidly added (Ce) over a 2-second interval. 0.2 Zr 0.2 Ti 0.2 Sn 0.2 Hf 0.2 O2 powder is stirred at a rate of 1 r / s for 10 s to obtain a mixed powder; then the mixed powder is quickly poured into a forging machine in 2 s, and the mold is preheated to 500°C.

[0026] Step 3: First, pressurize to 10MPa in 10s, hold the pressure for 150s, then depressurize to atmospheric pressure in 10s, then remove from the mold in 5s, place in a heating furnace with a preheated temperature of 800℃, keep warm for 4h, control the vacuum degree at 0.01Pa, then cool down to 460℃ at a rate of 1℃ / min, and finally air cool to room temperature.

[0027] Figure 2 This is a scanning electron microscope (SEM) image of the in-situ refined wear-resistant high-alloy steel prepared in this embodiment after corrosion. Figure 2 It can be seen that under the in-situ refining process, the carbides in the microstructure of wear-resistant high-alloy steel are significantly refined. Tests show that the wear-resistant high-alloy steel material prepared in this embodiment has a red hardness of 58HRC~64HRC at 600℃, a density of 99.6%, and a microhardness of 8GPa~16GPa.

[0028] The wear-resistant high-alloy steel material prepared by the above method can be applied to wear-resistant molds such as high-temperature environment hot working abrasives, cutting tools, and wear-resistant gears.

[0029] Comparative Example 1 This comparative example provides a method for preparing wear-resistant high-alloy steel, specifically including the following steps: Step 1: Select only high-alloy steel blocks as raw materials. By weight percentage, the high-alloy steel blocks comprise the following components: 18% Cr, 0.90% Mo, 2.10% V, 0.50% Si, 1.00% Nb, 0.20% Mn, and 0.40% W. In the high-alloy steel blocks, the volume fraction of M7C3 is 18% with a size of 10 μm, and the volume fraction of MC is 1.1% with a size of 0.5 μm. (Cr, Mo, W) 23 C6 has a volume fraction of 0.5% and a size of 0.2 μm.

[0030] Step 2: Heat the high alloy steel block in an induction heating furnace at a rate of 100℃ / s to 1400℃, with a vacuum of 0.1Pa, hold for 5s, and stir at a rate of 1r / s for 10s; then pour it into a die forging machine in 2s, with the die preheated to 500℃.

[0031] Step 3: First, pressurize to 10MPa in 10s, hold the pressure for 150s, then depressurize to atmospheric pressure in 10s, remove from the mold in 5s, place in a heating furnace with a preheated temperature of 800℃, keep warm for 4h with a vacuum degree of 0.01Pa, then cool down to 460℃ at a rate of 1℃ / min, and finally air cool to room temperature.

[0032] Figure 3 This is a scanning electron microscope (SEM) image of the corrosion-treated, pressure-bearing, wear-resistant high-alloy steel without added phases prepared in Comparative Example 1. Figure 3 It is known that under pressure and without added phases, the carbides in the microstructure of wear-resistant high-alloy steel exhibit an oriented growth trend, forming slender rods at least hundreds of micrometers in length. Tests show that the material prepared in this comparative example has a red hardness of 45HRC~52HRC at 600℃, a density of 98%, and a microhardness of 5GPa~12GPa.

[0033] Comparative Example 2 This comparative example provides a method for preparing wear-resistant high-alloy steel, specifically including the following steps: Step 1: Select only high-alloy steel blocks as raw materials. By weight percentage, the high-alloy steel blocks comprise the following components: 18% Cr, 0.90% Mo, 2.10% V, 0.50% Si, 1.00% Nb, 0.20% Mn, and 0.40% W. In the high-alloy steel blocks, the volume fraction of M7C3 is 18% with a size of 10 μm, and the volume fraction of MC is 1.1% with a size of 0.5 μm. (Cr, Mo, W) 23 C6 has a volume fraction of 0.5% and a size of 0.2 μm.

[0034] Step 2: Heat the high alloy steel block in an induction heating furnace at a rate of 100℃ / s to 1400℃, with a vacuum of 0.1Pa, hold for 5s, and stir at a rate of 1r / s for 10s; then pour it into a die forging machine in 2s, with the die preheated to 500℃.

[0035] Step 3: Remove from the mold in 5 seconds, place in a heating furnace with a preheated temperature of 800℃, keep warm for 4 hours with a vacuum degree of 0.01Pa, then cool down to 460℃ at a rate of 1℃ / min, and finally air cool to room temperature.

[0036] Figure 4This is a scanning electron microscope (SEM) image of the corrosion-free, untreated, wear-resistant high-alloy steel without added phases prepared in Comparative Example 2. Figure 4 It is known that in the pressureless casting process without added phases, the microstructure of wear-resistant high-alloy steel contains irregular bulk carbides and long rod-shaped structures. Tests showed that the material prepared in this comparative example has a red hardness of 40HRC~45HRC at 600℃, a density of 96%, and a microhardness of 4GPa~10GPa.

[0037] Example 2 This embodiment provides a method for in-situ refining carbides in wear-resistant high-alloy steel, specifically including the following steps: Step 1: Select high-alloy steel blocks and pyrochlore-structured high-entropy oxide powder as raw materials, and the mass ratio of the high-alloy steel blocks and pyrochlore-structured high-entropy oxide powder is 99:1; High-entropy oxide powder with pyrochlore structure was selected using Y2(Zr) 1 / 6 Ti 1 / 3 Ge 1 / 6 Hf 1 / 12 Sn 1 / 4 The high-alloy steel bulk material comprises 28% Cr, 2.50% Mo, 4.10% V, 0.80% Si, 1.50% Nb, 0.50% Mn, and 0.80% W by weight percentage. In the high-alloy steel bulk material, the volume fraction of M7C3 is 30% with a size of 500 μm, and the volume fraction of MC is 3.5% with a size of 5 μm. 23 C6 has a volume fraction of 1.5% and a size of 2 μm.

[0038] Step 2: First, heat the high-alloy steel block, then quickly add Y2(Zr) 1 / 6 Ti 1 / 3 Ge 1 / 6 Hf 1 / 12 Sn 1 / 4 2O7 powder is stirred evenly to obtain a mixed powder, which is then quickly poured onto a forging machine, with the mold preheated to 1100℃. The specific steps of this process are as follows: High-alloy steel blocks were heated in an induction furnace at a rate of 300℃ / s to 1600℃ under a vacuum of 1.1 Pa, held for 15 seconds, and then Y2(Zr) was rapidly added over a period of 12 seconds. 1 / 6 Ti 1 / 3 Ge 1 / 6 Hf 1 / 12 Sn 1 / 4)2O7 powder is stirred at a rate of 3r / s for 20s to obtain a mixed powder; then the mixed powder is quickly poured into a forging machine in 8s, and the mold is preheated to 1100℃.

[0039] Step 3: First, pressurize to 200MPa in 30s, hold the pressure for 250s, then depressurize to atmospheric pressure in 20s, then remove from the mold in 30s, place in a heating furnace with a preheated temperature of 1000℃, keep warm for 12h, control the vacuum degree at 0.1Pa, then cool down to 780℃ at a rate of 5℃ / min, and finally air cool to room temperature.

[0040] Figure 5 This is a scanning electron microscope (SEM) image of the in-situ refined wear-resistant high-alloy steel prepared in this embodiment after corrosion. Figure 5 It can be seen that under the in-situ refining process, the carbides in the microstructure of wear-resistant high-alloy steel are significantly refined. Tests show that the wear-resistant high-alloy steel material prepared in this embodiment has a red hardness of 56 HRC to 62 HRC at 600℃, a density of 99.2%, and a microhardness of 12 GPa to 16 GPa.

[0041] Example 3 This embodiment provides a method for in-situ refining carbides in wear-resistant high-alloy steel, specifically including the following steps: Step 1: Select high-alloy steel blocks and fluorite-structured high-entropy oxide powder as raw materials, and the mass ratio of the high-alloy steel blocks and fluorite-structured high-entropy oxide powder is 189:11; Among them, the high-entropy oxide powder with fluorite structure is selected from (Ce 0.2 Zr 0.2 Ti 0.2 Sn 0.2 Hf 0.2 O2 powder with a size of 85 μm; the high-alloy steel bulk material comprises, by weight percentage: 23% Cr, 1.70% Mo, 3.10% V, 0.65% Si, 1.25% Nb, 0.35% Mn, and 0.60% W; in the high-alloy steel bulk material, the volume fraction of M7C3 is 24% with a size of 255 μm, and the volume fraction of MC is 2.3% with a size of 2.75 μm, (Cr, Mo, W) 23 C6 has a volume fraction of 1.0% and a size of 1.1 μm.

[0042] Step 2: First, heat the high-alloy steel block, then quickly add (Ce) 0.2 Zr 0.2 Ti 0.2 Sn 0.2 Hf 0.2O2 powder is stirred evenly to obtain a mixed powder, which is then quickly poured onto a forging machine, with the mold preheated to 800°C. The specific steps of this process are as follows: High-alloy steel blocks were heated in an induction furnace at a rate of 200℃ / s to 1500℃, with a vacuum of 0.6 Pa, held for 10 seconds, and then rapidly added (Ce) over a period of 7 seconds. 0.2 Zr 0.2 Ti 0.2 Sn 0.2 Hf 0.2 O2 powder is stirred at a rate of 2 r / s for 15 s to obtain a mixed powder; then the mixed powder is quickly poured into a forging machine over a time of 5 s, and the mold is preheated to 800°C.

[0043] Step 3: First, pressurize to 105MPa in 20s, hold the pressure for 200s, then depressurize to atmospheric pressure in 15s, then demold in 17.5s, place in a heating furnace with a preheated temperature of 900℃, keep warm for 8 hours, control the vacuum degree at 0.055Pa, then cool to 620℃ at a rate of 3℃ / min, and finally air cool to room temperature.

[0044] Figure 6 This is a scanning electron microscope (SEM) image of the in-situ refined wear-resistant high-alloy steel prepared in this embodiment after corrosion. Figure 6 It can be seen that under the in-situ refining process, the carbides in the microstructure of wear-resistant high-alloy steel are significantly refined. Tests show that the wear-resistant high-alloy steel material prepared in this embodiment has a red hardness of 53HRC~59HRC at 600℃, a density of 98.9%, and a microhardness of 8GPa~15GPa.

[0045] Example 4 This embodiment provides a method for in-situ refining carbides in wear-resistant high-alloy steel, specifically including the following steps: Step 1: Select high-alloy steel blocks and pyrochlore-structured high-entropy oxide powder as raw materials, and the mass ratio of the high-alloy steel blocks and pyrochlore-structured high-entropy oxide powder is 97:3. The pyrochlore-structured high-entropy oxide powder is Y2(ZrTiGeHfSnSi)2O7 powder with a size of 100 μm. The high-alloy steel bulk material comprises, by weight percentage: 25% Cr, 2.0% Mo, 2.80% V, 0.60% Si, 1.20% Nb, 0.30% Mn, and 0.50% W. In the high-alloy steel bulk material, the volume fraction of M7C3 is 20% with a size of 50 μm, and the volume fraction of MC is 2.1% with a size of 3.5 μm. (Cr, Mo, W) 23 C6 has a volume fraction of 0.65% and a size of 1.2 μm.

[0046] Step 2: First, heat the high-alloy steel block, then quickly add Y2(ZrTiGeHfSnSi)2O7 powder, stir evenly to obtain a mixed powder, and then quickly pour the mixed powder onto a forging machine. The mold is preheated to 750°C. The specific steps of this process are as follows: The high-alloy steel block was heated in an induction heating furnace to 1520°C at a rate of 150°C / s, with a vacuum of 0.5 Pa and a holding time of 8s. Y2(ZrTiGeHfSnSi)2O7 powder was rapidly added over 5s while stirring at 1r / s for 12s to obtain a mixed powder. The mixed powder was then rapidly poured onto a die forging machine over 4s, with the die preheated to 750°C.

[0047] Step 3: First, pressurize to 100MPa in 15s, hold the pressure for 180s, then depressurize to atmospheric pressure in 12s, then remove from the mold in 20s, place in a heating furnace with a preheated temperature of 850℃, keep warm for 10h, control the vacuum degree at 0.05Pa, then cool down to 600℃ at a rate of 2℃ / min, and finally air cool to room temperature.

[0048] Figure 7 This is a scanning electron microscope (SEM) image of the in-situ refined wear-resistant high-alloy steel prepared in this embodiment after corrosion. Figure 7 It can be seen that under the in-situ refining process, the carbides in the microstructure of wear-resistant high-alloy steel are significantly refined. Tests show that the wear-resistant high-alloy steel material prepared in this embodiment has a red hardness of 57HRC~63HRC at 600℃, a density of 99.5%, and a microhardness of 9GPa~16GPa.

[0049] Comparing Examples 1-4 with Comparative Examples 1-2, it can be seen that the present invention simplifies the preparation process and significantly improves the material properties by employing a specific pressure forming process and combining a small amount of specific additive phases. The resulting material not only has excellent high-temperature resistance and good density, but also exhibits outstanding microhardness. In contrast, Comparative Example 1 did not use pyrochlore-structured high-entropy oxide / fluorite-structured high-entropy oxide powder as raw material, and Comparative Example 2 lacked pressure conditions and additive phases, resulting in a significantly lower density than the embodiments of the present invention (98% for Comparative Example 1 and 96% for Comparative Example 2); at the same time, its red hardness and microhardness are also inferior to those of the present invention.

[0050] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention.

[0051] It should be understood that the present invention is not limited to the content already described above, and various modifications and changes can be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for in-situ refining carbides in wear-resistant high-alloy steel, characterized in that, Specifically, the following steps are included: Step 1: Select high-alloy steel blocks and pyrochlore-structured high-entropy oxide / fluorite-structured high-entropy oxide powder as raw materials, and the mass ratio of the high-alloy steel blocks and pyrochlore-structured high-entropy oxide / fluorite-structured high-entropy oxide powder is 9:1~99:1; Step 2: First, heat the high alloy steel block, then quickly add pyrochlore structure high entropy oxide / fluorite structure high entropy oxide powder, stir evenly to obtain mixed powder, and then quickly pour the mixed powder onto the die forging machine, and preheat the die to 500℃~1100℃. Step 3: First, pressurize to 10MPa~200MPa in 10s~30s, hold the pressure for 150s~250s, then depressurize to atmospheric pressure in 10s~20s, then remove from the mold in 5s~30s, place in a heating furnace with a preheated temperature of 800℃~1000℃, keep warm for 4h~12h, control the vacuum degree at 0.01Pa~0.1Pa, then cool down to 460℃~780℃ at a rate of 1℃ / min~5℃ / min, and finally air cool to room temperature.

2. The method for in-situ refining wear-resistant high-alloy steel carbides according to claim 1, characterized in that, The intrinsic thermal conductivity of the pyrochlore-structured high-entropy oxide / fluorite-structured high-entropy oxide powder is 0.9 W / (m·K)~1.7 W / (m·K), and the flexural strength is 100 MPa~800 MPa.

3. The method for in-situ refining wear-resistant high-alloy steel carbides according to claim 2, characterized in that, The preparation process of the pyrochlore-structured high-entropy oxide / fluorite-structured high-entropy oxide powder is as follows: Prepare materials according to the target product and mix them according to the atomic ratio of the target product. Then, heat the mixture to 1200℃~1600℃ at a rate of 1℃ / min~5℃ / min, sinter for 1h~6h, and grind and sieve.

4. The method for in-situ refining wear-resistant high-alloy steel carbides according to claim 3, characterized in that, The fluorite-structured high-entropy oxide powder is (Ce) 0.2 Zr 0.2 Ti 0.2 Sn 0.2 Hf 0.2 The pyrochlore-structured high-entropy oxide powder is Y2(ZrTiGeHfSnSi)2O7 powder or Y2(Zr 1 / 6 Ti 1 / 3 Ge 1 / 6 Hf 1 / 12 Sn 1 / 4 )2O7 powder.

5. The method for in-situ refining wear-resistant high-alloy steel carbides according to claim 1, characterized in that, In the high-alloy steel block, the volume fraction of M7C3 is 18%~30%, and the size is 10μm~500μm; the volume fraction of MC is 1.1%~3.5%, and the size is 0.5μm~5μm; (Cr,Mo,W) 23 The volume fraction of C6 is 0.5% to 1.5%, and the size is 0.2 μm to 2 μm.

6. The method for in-situ refining wear-resistant high-alloy steel carbides according to claim 1, characterized in that, The size of the pyrochlore-structured high-entropy oxide / fluorite-structured high-entropy oxide powder is 20μm~150μm.

7. The method for in-situ refining wear-resistant high-alloy steel carbides according to claim 1, characterized in that, In step 2, the time taken to add the pyrochlore-structured high-entropy oxide / fluorite-structured high-entropy oxide powder is 2s~12s, and the time taken to pour the mixed powder onto the forging machine is 2s~8s.

8. The method for in-situ refining wear-resistant high-alloy steel carbides according to claim 7, characterized in that, Step 2 specifically involves: The high-alloy steel block is heated in an induction heating furnace to 1400℃~1600℃ at a rate of 100℃ / s~300℃ / s, with a vacuum degree of 0.1Pa~1.1Pa, and held for 5s~15s. Powdered pyrochlore-structured high-entropy oxide / fluorite-structured high-entropy oxide is added over a period of 2s~12s, while stirring at a rate of 1r / s~3r / s for 10s~20s to obtain a mixed powder. The mixed powder is then poured into a die forging machine over a period of 2s~8s, and the die is preheated to 500℃~1100℃.

9. A wear-resistant high-alloy steel material prepared by the method according to any one of claims 1 to 8, characterized in that, The wear-resistant high-alloy steel material has a red hardness of 50HRC~65HRC, a density of 98.5%~99.9%, and a microhardness of 6GPa~18GPa.

10. The application of a wear-resistant high-alloy steel material prepared by the method according to any one of claims 1 to 8 in high-speed cutting wear-resistant tools, characterized in that, The application environment temperature range is from room temperature to 650℃.

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