Novel wear-resistant material and preparation method thereof

Abstract

The invention discloses a novel wear-resistant material as well as a preparation method and application thereof. The novel wear-resistant material comprises the following components in percentage by weight: 3%-5% of C, 10%-15% of V, 5%-8% of Cr, 2%-3% of Mo, 2%-3% of Nb, 0.5%-1% of Al, 0.5%-1% of B, 0.15%-0.3% of La, 0.15%-0.3% of Ce and the balance of Fe. VC in the novel wear-resistant material is in spherical dispersion distribution, M7C3 is in a discontinuous net shape, and M is selected from at least one of Cr and Fe. According to the scheme, the distribution condition of VC carbide is guaranteed by controlling the vanadium content within the range of 10-15%, so that the toughness and strength of the material are enhanced, and carbide coarsening and brittle fracture caused by excessive vanadium content are avoided; and meanwhile, rare earth elements La and Ce are added, so that the melt is effectively purified, grains are refined, the carbide form and distribution are improved, and the mechanical property and stability of the material are further enhanced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of wear-resistant materials, and particularly relates to a novel wear-resistant material and a preparation method thereof. BACKGROUND

[0002] In many fields such as machinery, metallurgy, power, building materials, national defense, ships, railways, coal, and chemical industry, there is an urgent need for high-strength and high-hardness wear-resistant materials. Such materials are widely used in core components of key equipment, such as excavator bucket teeth, crusher hammers, ball mill liners, and rolling mill rolls in the metallurgical industry, coal mill grinding rings and impact plates in the power industry, and various slurry pumps, and have a significantly longer service life than traditional materials.

[0003] However, the manufacturing process of high-performance wear-resistant alloys that meet these harsh working conditions itself faces challenges. Existing commonly used materials such as high-chromium cast iron still have insufficient wear resistance in some extreme working conditions, and although hard alloys have excellent performance, their high cost limits their large-scale application. To address this technical bottleneck, a novel wear-resistant material, high-vanadium steel, is developed in the present application.

[0004] CN 117051322 A discloses a high-vanadium wear-resistant alloy and a preparation method thereof. The high-vanadium wear-resistant alloy has a chemical composition of C 3-5wt%, V 8-15wt%, Cr 5-9wt%, Mo 2-4wt%, Mn 0.2-0.7wt%, Si 0.5-1.0wt%, Al 0.5-1.0wt%, W 0.4-1.0wt%, Ni 0.4-1.0wt%, Co 0.5-1.5wt%, Nb 0.2-1.0wt%, B 0.1-1wt%, N 0.05-0.15wt%, and the balance of Fe and unavoidable impurities, in terms of weight percentage. The scheme uses a normalizing + tempering heat treatment process through composition control and heat treatment means. However, this process has the defect of causing a decrease in the toughness of the workpiece, and the hardness and impact toughness of the obtained wear-resistant alloy still cannot meet the needs of existing working conditions.

[0005] CN 116676544 A discloses a high-chromium high-vanadium high-speed steel and a preparation method thereof. The high-chromium high-vanadium high-speed steel comprises, in terms of mass percentage, carbon 0.8%-1.55%, vanadium 3%-6%, chromium 3%-9%, molybdenum 0.5%-2.5%, manganese 0.5%-1%, silicon 0.5%-1%, nickel 0.2%-0.8%, sulfur less than 0.05%, phosphorus less than 0.05%, and the balance of iron. The preparation process includes melting, annealing, hot forging, quenching, and tempering. The obtained high-chromium high-vanadium high-speed steel has a Rockwell hardness HRC of 60-68 and an impact toughness of 16-25 J / cm 2, the room temperature and high temperature wear resistance is increased by more than 60% than traditional cast high vanadium high speed steel. The heat treatment process of normalizing + tempering is adopted, however, there is a problem of low hardness, which cannot meet the wear resistance requirement. SUMMARY

[0006] The present application aims to overcome the deficiencies in the prior art, and designs a new wear-resistant material with excellent hardness and wear resistance, and certain toughness. The material has outstanding wear resistance, and exhibits significant advantages in shield tunneling machine cutter, slurry pump flow parts, oil drill pipe and other occasions with extremely high wear resistance requirements. The overall performance and service life of such components are improved, so that they remain reliable and stable during subsequent processing and service.

[0007] According to a first aspect of the present application, a new wear-resistant material is provided, the composition of the new wear-resistant material is as follows in terms of weight percentage: C: 3%~5%, V: 10%~15%, Cr: 5%~8%, Mo: 2%~3%, Nb: 2%~3%, Al: 0.5%~1%, B: 0.5%~1%, La: 0.15%~0.3%, Ce: 0.15%~0.3%, the balance is Fe and inevitable impurities, and C≈0.2V+0.2Cr+0.3 is met; VC in the new wear-resistant material is dispersed in a spherical shape, and M7C3 is in a non-continuous network, wherein M is selected from at least one of Cr and Fe.

[0008] The following is the role of each element: C: combined with V, Cr, Mo, Nb and other elements, forms various high-hardness carbides, dissolves in austenite, and forms high-hardness martensite after quenching; V: is a strong carbide-forming element, mainly forming VC; Cr: improves hardenability, forms M7C3 type carbide dissolved during quenching, provides alloying degree for the matrix, and enhances tempering stability; Mo: forms M2C and M6C type carbides, reduces the overheating sensitivity of the steel, prevents grain coarsening, and inhibits the occurrence of temper brittleness in the steel containing Cr. Nb: forms carbide NbC, hinders the growth of austenite grains, and improves the strength and toughness of the material; Al: deoxidizes the molten steel, and improves the oxidation resistance temperature of the steel at high temperature; B: improves hardenability, segregates at grain boundaries, reduces grain boundary energy, and avoids the nucleation of ferrite and pearlite at grain boundaries; La: reacts with O and S in the steel to form oxides or sulfides, floats to the slag, and purifies the molten steel; Ce: reacts with O and S in the steel to form oxides or sulfides, floats to the slag, and purifies the molten steel; C / V / Cr: C≈0.2V+0.2Cr+0.3. C and V can form a large number of fine, dispersed, hard VC particles after heat treatment, which greatly improves the wear resistance of the steel through dispersion strengthening, and at the same time, due to its high temperature stability, ensures the red hardness of the steel. C and Cr form M7C3 carbide, which dissolves during austenitizing, increasing the C and Cr content in austenite, significantly improving the stability of the supercooled austenite and improving the hardenability. When heated at high temperature, the carbide of Cr is easy to dissolve and aggregate and grow, leading to austenite grain coarsening. The VC formed by V is very stable, and even at high temperature, it remains fine and can effectively pin the grain boundary, thereby refining the structure.

[0009] Based on the above technical scheme, the hardness of the new wear-resistant material is 67-69HRC, the microhardness is 900-1100HV, and the compressive strength is 3300-3500MPa.

[0010] According to the second aspect of the present application, a preparation method of a new wear-resistant material is provided, which comprises the following steps: Step 1, preparation of ingot: the ingredients of the raw materials are as follows in terms of weight percentage: C: 3-5%, V: 10-15%, Cr: 5-8%, Mo: 2-3%, Nb: 2-3%, Al: 0.5-1%, B: 0.5-1%, La: 0.15-0.3%, Ce: 0.15-0.3%, Fe: balance; the above raw materials are placed in a medium-frequency induction melting furnace for vacuum melting, which is divided into two stages, in the first stage, the raw materials except La and Ce are weighed and calculated and then loaded into a crucible for primary refining; in the second stage, La and Ce are added for secondary refining and pouring to obtain an ingot; Step 2, heat treatment: the ingot obtained in step 1 is subjected to normalizing treatment and tempering treatment in a vacuum heat treatment furnace to obtain a wear-resistant material.

[0011] Based on the above technical scheme, the primary refining in step 1 is as follows: the raw materials except La and Ce are weighed and calculated and then loaded into a crucible, the cooling water is started, vacuum is extracted to 0.1Mpa, argon is filled after the vacuum system is closed, the vacuum extraction-argon filling operation is repeated, and the primary refining is carried out at 1500-1550℃ for 8-10min.

[0012] Based on the above technical scheme, the secondary refining in step 1 is as follows: after adding La and Ce, secondary refining is carried out at 1400-1450℃ for 8-10min at a rotation speed of 30-60r / min.

[0013] Based on the above technical scheme, the normalizing treatment in step 2 is specifically: the cast ingot obtained in step 1 is heated from 20-30℃ to the normalizing temperature 1040-1050℃ at a heating rate of 0.5-1℃ / min, and is kept for 1.5-2h, and is air-cooled to room temperature.

[0014] Based on the above technical scheme, the tempering treatment in step 2 is specifically: the cast ingot after normalizing treatment is heated from 20-30℃ to 270-300℃ at a heating rate of 0.5-1℃ / min, and is kept for 1.5-2h, and is air-cooled to room temperature.

[0015] According to the third aspect of the present application, the application of a new wear-resistant material in a tool coating is provided, and the service life of the tool is more than 8 hours, and the service life of M2 high-speed steel is more than 2 hours, which is about 4 times longer than that of M2 high-speed steel.

[0016] Advantages (1) The technical scheme disclosed in the present application realizes excellent comprehensive performance of the material through scientific component ratio design, and effectively improves the wear resistance by the synergistic effect of each element, i.e. carbon and vanadium, chromium (to form high-hardness carbide), the vanadium content is controlled within the range of 10-15%, which can ensure the VC carbide to be dispersed in a spherical shape, enhance the toughness and strength of the material, and avoid the coarsening of the carbide and brittle fracture caused by excessive amount; the addition of rare earth elements La and Ce effectively purifies the melt, refines the grains, and improves the morphology and distribution of the carbide, further enhancing the mechanical properties and stability of the material.

[0017] (2) The preparation process of the technical scheme disclosed in the present application is designed precisely, and has operability and stability. Vacuum melting combined with multiple vacuum-pumping and argon-filling circulation operations greatly reduces the gas and impurity content, and improves the purity of the material; stage refining and late addition of rare earth elements effectively prevent element burning loss and segregation, and ensure the uniformity of the components. The heat treatment process parameters (normalizing temperature, tempering temperature, holding time and heating rate) are optimized, so that the VC carbide is spheroidized and dispersed, the M7C3 carbide is in a discontinuous network, the structure is significantly refined, the internal stress is reduced, and micro-cracks are avoided, thereby realizing high hardness, high compressive strength and good toughness at the same time.

[0018] (3) The material obtained by the technical scheme disclosed in the present application has excellent performance, the hardness can reach 67-69HRC, the microhardness is 900-1100 HV, and the compressive strength is as high as 3300-3500 MPa, which is much higher than that of conventional wear-resistant materials. The material has excellent toughness and compressive performance while maintaining high wear resistance, and is suitable for wear-resistant parts under harsh working conditions, and has wide industrial application prospects. Therefore, the present application embodies significant innovation in component design, process control and structure regulation, successfully realizes a good balance between wear resistance, strength and toughness of the material, and has important practical value and popularization significance. Attached Figure Description

[0019] Appendix Figure 1 The microstructure of the novel wear-resistant material prepared in Example 1; Appendix Figure 2 The microstructure of the novel wear-resistant material prepared in Example 2; Appendix Figure 3 The room temperature compressive stress-strain curve of the novel wear-resistant material prepared in Example 3; Appendix Figure 4 The microstructure of the wear-resistant material prepared in Comparative Example 1; Appendix Figure 5 The compressive strength of the wear-resistant material prepared in Comparative Example 1 is compared with that of the novel wear-resistant material prepared in Example 1. Appendix Figure 6 The microstructure of the wear-resistant material prepared in Comparative Example 2; Appendix Figure 7 The hardness and compressive strength of the wear-resistant material prepared in Comparative Example 2 are compared with those of the novel wear-resistant material prepared in Example 1. Appendix Figure 8 Comparison of austenite content and hardness between the wear-resistant material prepared in Comparative Example 3 and the novel wear-resistant material prepared in Example 1; Appendix Figure 9 The microstructure of the wear-resistant material prepared in Comparative Example 4; Appendix Figure 10 The compressive strength of the wear-resistant material prepared in Comparative Example 4 is compared with that of the novel wear-resistant material prepared in Example 1. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The present invention provides a novel wear-resistant material in the specific embodiments section. The composition of the novel wear-resistant material by weight percentage is as follows: C: 3%~5%, V: 10%~15%, Cr: 5%~8%, Mo: 2%~3%, Nb: 2%~3%, Al: 0.5%~1%, B: 0.5%~1%, La: 0.15%~0.3%, Ce: 0.15%~0.3%, with the balance being Fe and unavoidable impurities, satisfying C≈0.2V+0.2Cr+0.3; in the novel wear-resistant material, VC is spherically dispersed, and M7C3 is a discontinuous network, wherein M is selected from at least one of Cr and Fe.

[0022] Based on the above technical scheme, the hardness of the novel wear-resistant material is 67-69 HRC, the microhardness is 900-1100 HV, and the compressive strength is 3300-3500 MPa.

[0023] The present application also provides a preparation method of the novel wear-resistant material in the specific embodiment part, and the preparation method comprises the following steps: Step 1, preparation of ingot: the ingredients of the raw materials according to the weight percentage are as follows: C: 3-5%, V: 10-15%, Cr: 5-8%, Mo: 2-3%, Nb: 2-3%, Al: 0.5-1%, B: 0.5-1%, La: 0.15-0.3%, Ce: 0.15-0.3%, and Fe balance; the above raw materials are placed in a medium-frequency induction melting furnace for vacuum melting, and the melting is divided into two stages, in the first stage, the raw materials except La and Ce are weighed and calculated and then loaded into a crucible for primary refining; in the second stage, La and Ce are added for secondary refining and pouring, and an ingot is obtained; Step 2, heat treatment: the ingot obtained in step 1 is subjected to normalizing treatment and tempering treatment in a vacuum heat treatment furnace, and the wear-resistant material is obtained.

[0024] Based on the above technical scheme, the primary refining is specifically as follows: the raw materials except La and Ce in the raw materials are weighed and calculated and then loaded into a crucible, the cooling water is started, vacuum is extracted to 0.1 Mpa, argon is filled after the vacuum system is closed, the vacuum extraction-argon filling operation is repeated, and the primary refining is carried out at 1500-1550℃ for 8-10 min.

[0025] Based on the above technical scheme, the secondary refining is specifically as follows: after La and Ce are added, the secondary refining is carried out at 1400-1450℃ for 8-10 min at a rotating speed of 30-60 r / min.

[0026] Based on the above technical scheme, the normalizing treatment is specifically as follows: the ingot obtained in step 1 is heated from 20-30℃ to the normalizing temperature 1040-1050℃ at a heating rate of 0.5-1℃ / min, is kept for 1.5-2 h, and is air-cooled to room temperature.

[0027] Based on the above technical scheme, the tempering treatment is specifically as follows: the ingot after the normalizing treatment is heated from 20-30℃ to 270-300℃ at a heating rate of 0.5-1℃ / min, is kept for 1.5-2 h, and is air-cooled to room temperature.

[0028] Example The preparation method of the wear-resistant material comprises the following steps: S1, the raw materials are weighed according to the raw material ingredient proportioning table in examples 1-3 and comparative examples.

[0029] S2. The raw materials used in step S1 were melted using a vacuum medium-frequency induction melting furnace with argon protection, purchased from Shenyang Vacuum Technology Research Institute Co., Ltd. The operation process is as follows: First, the cooling water system was started; the raw materials, except for La and Ce, were weighed and calculated and loaded into the crucible, while La and Ce were placed in the secondary feeding bin for later use; the furnace door was closed and a vacuum was drawn; then the vacuum system was shut off, and argon gas was introduced into the furnace cavity; after purging, the argon gas device was shut off and a vacuum was drawn again; the above vacuuming-argon purging operation was repeated three times to achieve furnace cleaning. The relevant melting parameters are shown in Table 2, and the relevant heat treatment parameters are shown in Table 3. The microstructure of the wear-resistant material obtained in Example 1 is as follows: Figure 1 As shown, by Figure 1 It can be seen that VC is spherically dispersed in the matrix, while M7C3 exhibits a discontinuous network distribution; the microstructure of the wear-resistant material prepared in Example 2 is as follows. Figure 2 As shown, compared with Example 1, due to the increase in C and V content, the VC content is slightly higher and still shows a diffuse distribution, while M7C3 shows no significant change. Figure 3 The room temperature compressive stress-strain curve of the wear-resistant material prepared in Example 3; Figure 4 The microstructure of the wear-resistant material prepared in Comparative Example 1; Figure 5 The results show the comparison of the compressive strength of the wear-resistant materials prepared in Comparative Example 1 and Example 1; Figure 6 The microstructure of the wear-resistant material prepared in Comparative Example 2; Figure 7 The results show the comparison of hardness and compressive strength of the wear-resistant materials prepared in Comparative Example 2 and Example 1; Figure 8 The results show the comparison of austenite content and hardness of the wear-resistant materials prepared in Comparative Example 3 and Example 1; Figure 9 The microstructure of the wear-resistant material prepared in Comparative Example 4; Figure 10 The results show the comparison of the compressive strength of the wear-resistant materials prepared in Comparative Example 4 and Example 1.

[0030] Table 1 shows the raw material composition of wear-resistant materials.

[0031] Table 2 shows the relevant parameters for smelting.

[0032] Table 3 shows the heat treatment-related parameters.

[0033] Table 4 shows the microstructure and properties of wear-resistant materials.

[0034] From the above examples and comparative examples, it can be seen that the V and Cr element content range and the normalizing heat treatment process are the key to obtaining the best material performance. When the V content exceeds the range defined in the application, VC will obviously segregate and coarsen, forming large block precipitates, which seriously damages the mechanical properties of the material; when the Cr content exceeds the upper limit of the application, a large range of network M7C3 carbides will be formed in the structure, which adversely affects the strength and toughness of the material. At the same time, in the heat treatment process, normalizing temperature higher than the range of the application will lead to structure coarsening, and lower than the range of the application will not fully achieve the solid solution of alloying elements and the homogenization of the structure, both of which will lead to the decline of the material performance. In summary, the combination of the composition design and the heat treatment process provided by the application can effectively ensure that the material obtains a fine and uniform structure and excellent comprehensive performance.

[0035] The above is only an embodiment of the application, and does not limit the application in any form. The application can have other forms of embodiments according to the above structure and function, and will not be listed one by one. Therefore, any skilled person in the art, without departing from the scope of the technical scheme of the application, according to the technical essence of the application, any simple modification, equivalent change and modification of the above embodiments, still belongs to the scope of the technical scheme of the application.

Claims

1. A novel wear resistant material, characterized in that, The new wear-resistant material comprises the following components in percentage by weight: C: 3-5%, V: 10-15%, Cr: 5-8%, Mo: 2-3%, Nb: 2-3%, Al: 0.5-1%, B: 0.5-1%, La: 0.15-0.3%, Ce: 0.15-0.3%, and the balance of Fe and inevitable impurities, and satisfies C≈0.2V+0.2Cr+0.3; VC in the new wear-resistant material is in a globular dispersed distribution, and M7C3 is in a non-continuous network, wherein M is at least one selected from Cr and Fe.

2. The novel wear resistant material according to claim 1, characterized in that, The new wear-resistant material has a hardness of 67-69 HRC, a microhardness of 900-1100 HV, and a compressive strength of 3300-3500 MPa.

3. The method for producing the novel wear-resistant material according to any one of claims 1 to 2, characterized in that, The preparation method comprises the following steps: Step 1: preparation of an ingot: the components of raw materials in percentage by weight are as follows: C: 3-5%, V: 10-15%, Cr: 5-8%, Mo: 2-3%, Nb: 2-3%, Al: 0.5-1%, B: 0.5-1%, La: 0.15-0.3%, Ce: 0.15-0.3%, and the balance of Fe; the above raw materials are placed in a medium-frequency induction melting furnace for vacuum melting, and the melting is divided into two stages: in the first stage, the raw materials except La and Ce are weighed and calculated and then loaded into a crucible for primary refining; in the second stage, La and Ce are added for secondary refining and pouring, so as to obtain an ingot; Step 2: heat treatment: the ingot obtained in step 1 is subjected to normalizing treatment and tempering treatment in a vacuum heat treatment furnace, so as to obtain a wear-resistant material.

4. The production method according to claim 3, characterized by, The primary refining in step 1 is specifically as follows: the raw materials except La and Ce are weighed and calculated and then loaded into a crucible, cooling water is started, vacuum is extracted to 0.1 MPa, argon is filled after the vacuum system is closed, vacuum extraction-argon filling operation is repeated, and primary refining is carried out at 1500-1550 ℃ for 8-10 min.

5. The preparation method according to claim 3, characterized in that, The secondary refining in step 1 is specifically as follows: after La and Ce are added, secondary refining is carried out at 1400-1450 ℃ for 8-10 min at a rotating speed of 30-60 r / min.

6. The preparation method according to claim 3, characterized in that, The normalizing treatment in step 2 is specifically as follows: the ingot obtained in step 1 is heated from 20-30 ℃ to normalizing temperature 1040-1050 ℃ at a heating rate of 0.5-1 ℃ / min, is kept for 1.5-2 h, and is air-cooled to room temperature.

7. The preparation method according to claim 3, characterized in that, The tempering treatment in step 2 is specifically as follows: the ingot after the normalizing treatment is heated from 20-30 ℃ to 270-300 ℃ at a heating rate of 0.5-1 ℃ / min, is kept for 1.5-2 h, and is air-cooled to room temperature.

8. Application of the new wear-resistant material prepared by the preparation method in any one of claims 3-7 in a cutter coating.

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