High-chromium high-vanadium high-speed steel and preparation method thereof

Abstract

This invention relates to a high-chromium, high-vanadium high-speed steel and its preparation method. The high-chromium, high-vanadium high-speed steel comprises, by mass percentage: 0.8%-1.55% carbon, 3%-6% vanadium, 3%-9% chromium, 0.5%-2.5% molybdenum, 0.5%-1% manganese, 0.5%-1% silicon, 0.2%-0.8% nickel, less than 0.05% sulfur, less than 0.05% phosphorus, with the balance being iron. The preparation process includes smelting, annealing, hot forging, quenching, and tempering. The resulting high-chromium, high-vanadium high-speed steel has a Rockwell hardness (HRC) of 60-68 and an impact toughness of 16-25 J / cm². 2 The wear resistance at both room temperature and high temperature is improved by more than 60% compared with traditional cast high-vanadium high-speed steel. This invention optimizes the carbon content and significantly reduces the carbide size to 0.5-2μm through annealing and hot forging, achieving a uniformly dispersed distribution of carbides. Combined with oil quenching and tempering, while maintaining a hardness of HRC60-68, its impact toughness is significantly improved. The prepared high-chromium high-vanadium high-speed steel has high hardness, good impact toughness, and excellent high-temperature wear resistance.

Description

Technical Field

[0001] This invention belongs to the field of alloy steel technology, specifically relating to a high-chromium, high-vanadium high-speed steel and its preparation method. Background Technology

[0002] High-vanadium high-speed steel is widely used in continuous casting rolls, cold working dies, mining equipment, and cutting tools due to its extremely high hardness and good wear resistance, resulting in a huge annual loss. Currently, the most widely used high-vanadium high-speed steel is as-cast, with a carbon content of 1.8%–3.1% and a vanadium content of 6%–10%. After complex heat treatment, various types of carbides, represented by VC (MC, M2C, M7C3, etc.), are distributed in the steel matrix, achieving high hardness and high wear resistance. However, due to the high carbon and alloy content, its forging performance is poor, and the large size of the carbides results in a significant difference in hardness between the carbides and the matrix, poor fusion, and generally low impact toughness, only 5–10 J / cm². 2 It has poor red hardness and cannot meet the wear conditions in environments above 600℃.

[0003] Today, with the continuous development of non-ferrous refractory material preparation and rolling equipment, the market has put forward higher requirements for the wear resistance of materials under high temperature environments. To this end, we have proposed a preparation method for high-chromium and high-vanadium high-speed steel, which optimizes the composition and preparation process of traditional cast high-vanadium high-speed steel. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, this invention provides a high-chromium, high-vanadium high-speed steel and its preparation method, with the aim of optimizing the composition ratio of the high-speed steel to improve its impact toughness and wear resistance at both room temperature and high temperature.

[0005] This invention is specifically achieved through the following technical solution: A high-chromium, high-vanadium high-speed steel is proposed according to this invention, the composition of which, by mass percentage, includes: 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 being iron. This high-chromium, high-vanadium high-speed steel has a Rockwell hardness (HRC) of 60–68 and an impact toughness of 16–25 J / cm². 2 Its wear resistance at both room temperature and high temperature is more than 60% higher than that of traditional cast high-vanadium high-speed steel.

[0006] More preferably, the composition of the high-chromium, high-vanadium high-speed steel by mass percentage may be: carbon 1.51%, vanadium 6%, chromium 4.97%, molybdenum 0.52%, manganese 0.9%, silicon 0.83%, nickel 0.68%, sulfur 0.013%, phosphorus 0.023%, with the balance being iron.

[0007] More preferably, the composition of the high-chromium, high-vanadium high-speed steel by mass percentage may be: carbon 1.03%, vanadium 3.5%, chromium 8.4%, molybdenum 2.1%, manganese 0.61%, silicon 0.75%, nickel 0.5%, sulfur 0.015%, phosphorus 0.021%, with the balance being iron.

[0008] Furthermore, the raw materials for the high-chromium, high-vanadium high-speed steel include: iron rods with a purity of 99.5% and a diameter of 30mm to 80mm; carbon powder particles with a particle size of 0.5mm to 0.8mm; ferrovanadium particles containing 60% vanadium; ferrochrome particles containing 70% chromium; ferromolybdenum particles containing 60% molybdenum; ferromanganese sheets containing 80% manganese; ferrosilicon blocks containing 50% silicon; and nickel powder with a purity of 98%. The alloy particles used have a size of 3mm to 10mm. The alloy particles refer to raw materials other than iron rods and carbon powder particles, including ferrovanadium particles containing 60% vanadium; ferrochrome particles containing 70% chromium; ferromolybdenum particles containing 60% molybdenum; ferromanganese sheets containing 80% manganese; ferrosilicon blocks containing 50% silicon; and nickel powder with a purity of 98%.

[0009] This invention also provides a method for preparing high-chromium, high-vanadium high-speed steel, specifically including the following steps:

[0010] S1. Raw materials are selected according to the mass percentage of the high-chromium, high-vanadium high-speed steel composition. The mass percentage of the high-chromium, high-vanadium high-speed steel composition is as follows: 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 is iron. The raw materials include: iron rods with a purity of 99.5% and a diameter of 30mm–80mm, carbon powder particles with a particle size of 0.5mm–0.8mm, vanadium-iron particles containing 60% vanadium, chromium-iron particles containing 70% chromium, molybdenum-iron particles containing 60% molybdenum, manganese-iron sheets containing 80% manganese, silicon-iron blocks containing 50% silicon, and nickel powder with a purity of 98%.

[0011] S2. The raw materials taken in step S1 are smelted using a vacuum high-frequency induction melting furnace with argon protection: First, the cooling water system of the vacuum high-frequency induction melting furnace is turned on. The pre-weighed and calculated iron bars are placed into the crucible inside the furnace, and the proportioned carbon powder particles and alloy particles are placed into the secondary feeding bin for later use. The furnace door is closed and a vacuum of 1×10⁻⁶ is drawn. -1 MPa, then shut off the vacuum system, fill the furnace cavity with argon gas to -0.05MPa to 0.01MPa, then shut off the argon gas device and evacuate the vacuum. Repeat this process three times to clean the furnace.

[0012] Heating and smelting: When the furnace temperature is 1550℃~1580℃, slowly add carbon powder particles and alloy particles through the secondary feeding bin. Then start the stirring device to stir the crucible at a speed of 30 rpm until all the materials are dissolved. Control the steel pouring temperature to 1500℃~1550℃ and pour it into a circular copper mold with a water circulation device in a vacuum high-frequency induction melting furnace. After cooling, break the vacuum and remove it from the furnace to obtain a steel billet.

[0013] S3. Annealing treatment: Heat the steel billet obtained in step S2 to 700-850℃ at a rate of 6℃ / min to 8℃ / min, hold it at that temperature for 60 to 90 minutes, and then slowly cool it in the furnace to 450℃ to 500℃. Remove it from the furnace and air cool it to room temperature.

[0014] S4. Hot forging of steel billets: The steel billets obtained in step S3 are heated to the initial forging temperature of 1050℃-1100℃ at a rate of 6℃ / min to 8℃ / min, held at this temperature for 50 to 70 minutes, and then forged. The forging process includes: four upsetting passes with a 120kg to 200kg hammer, with the downward pressure not exceeding 1 / 4 of the ingot height; four drawing passes with a 120kg to 200kg hammer, with the drawing length not exceeding 1 / 4 of the ingot length; four upsetting passes with a 350kg to 600kg hammer, with the downward pressure not exceeding 1 / 3 of the ingot height; four drawing passes with a 350kg to 600kg hammer, with the drawing length not exceeding 1 / 3 of the ingot length; the final forging temperature is controlled at 900℃ to 950℃, and then cooled to room temperature in the furnace.

[0015] S5. Steel billet quenching treatment: Heat the steel billet obtained in step S4 to 900℃~950℃ at a rate of 6℃ / min~8℃ / min, hold for 60~90min, and oil cool to room temperature.

[0016] S6. Tempering treatment of steel billet: Heat the steel billet obtained in step S5 to 230℃~280℃ at a rate of 3℃ / min~5℃ / min, hold for 70~90min, remove from the furnace and air cool to room temperature to obtain high chromium and high vanadium high-speed steel.

[0017] Further, the composition of the high-chromium, high-vanadium high-speed steel in step S1 is preferably as follows by mass percentage: carbon 1.51%, vanadium 6%, chromium 4.97%, molybdenum 0.52%, manganese 0.9%, silicon 0.83%, nickel 0.68%, sulfur 0.013%, phosphorus 0.023%, with the balance being iron;

[0018] Alternatively, the composition of high-chromium, high-vanadium high-speed steel is preferably as follows by mass percentage: carbon 1.03%, vanadium 3.5%, chromium 8.4%, molybdenum 2.1%, manganese 0.61%, silicon 0.75%, nickel 0.5%, sulfur 0.015%, phosphorus 0.021%, with the balance being iron.

[0019] Furthermore, the initial forging temperature in step S4 is preferably 1060°C, and the final forging temperature is preferably 940°C.

[0020] Furthermore, the quenching oil used for oil cooling in step S5 is a mineral oil containing 0.5 wt.% refrigerant and 1 wt.% sodium salt. The refrigerant can be petroleum resin, and the sodium salt can be industrial sodium chloride.

[0021] The high-chromium, high-vanadium high-speed steel prepared according to the above method has a Rockwell hardness of HRC 60–68 and an impact toughness of 16–25 J / cm. 2 Its wear resistance at both room temperature and high temperature is more than 60% higher than that of traditional cast high-vanadium high-speed steel.

[0022] Compared with existing technologies, this invention has significant advantages and beneficial effects. Through the above technical solution, this invention achieves considerable technological advancement and practicality, and has broad application value, possessing at least the following advantages:

[0023] This invention optimizes the composition of high-chromium, high-vanadium high-speed steel, specifically the carbon and vanadium content. Through annealing and hot forging, the size of the carbides is significantly reduced to 0.5–2 μm, achieving a uniformly dispersed distribution. Furthermore, through oil quenching and tempering, while maintaining a hardness of HRC 60–68, the impact toughness of the high-speed steel is significantly improved, reaching 16–25 J / cm². 2 Compared with traditional cast high-vanadium high-speed steel, the wear resistance at both room temperature and high temperature is improved by more than 60%. The prepared high-chromium high-vanadium high-speed steel has high hardness, good impact toughness, and excellent high-temperature wear resistance. Attached Figure Description

[0024] Figure 1 This is a three-dimensional view of the high-chromium, high-vanadium high-speed steel sample prepared according to the present invention.

[0025] Figure 2 yes Figure 1 The main view.

[0026] Figure 3 yes Figure 2 Top view.

[0027] Figure 4 This is a TEM image of the high-chromium, high-vanadium high-speed steel obtained in Example 3. Detailed Implementation

[0028] 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.

[0029] Example 1:

[0030] The composition of high-chromium, high-vanadium high-speed steel by mass percentage is as follows: carbon 1.51%, vanadium 6%, chromium 4.97%, molybdenum 0.52%, manganese 0.9%, silicon 0.83%, nickel 0.68%, sulfur 0.013%, phosphorus 0.023%, with the balance being iron.

[0031] The preparation method of the above-mentioned high-chromium, high-vanadium high-speed steel includes the following steps:

[0032] S1. Raw materials with a purity of 99.5% are selected according to the above composition ratio of high-chromium and high-vanadium high-speed steel. Iron rods, carbon powder particles with a particle size of 0.5mm to 0.8mm, ferrovanadium particles containing 60% vanadium, ferrochrome particles containing 70% chromium, ferromolybdenum particles containing 60% molybdenum, ferromanganese sheets containing 80% manganese, ferrosilicon blocks containing 50% silicon, and nickel powder with a purity of 98%; the alloy particles used have a size of 3mm to 10mm. The alloy particles refer to: ferrovanadium particles containing 60% vanadium, ferrochrome particles containing 70% chromium, ferromolybdenum particles containing 60% molybdenum, ferromanganese sheets containing 80% manganese, ferrosilicon blocks containing 50% silicon, and nickel powder with a purity of 98%.

[0033] S2. The raw materials taken in step S1 are smelted using a vacuum high-frequency induction melting furnace with argon protection: First, the cooling water system of the vacuum high-frequency induction melting furnace is turned on. The pre-weighed and calculated iron bars are placed into the crucible inside the furnace, and the proportioned carbon powder particles and alloy particles are placed into the secondary feeding bin for later use. The furnace door is closed and a vacuum of 1×10⁻⁶ is drawn. -1 The pressure is increased to MPa, then the vacuum system is shut off, and argon gas is introduced into the furnace cavity to -0.05MPa to 0.01MPa. After that, the argon gas device is shut off and the vacuum is evacuated. The furnace is cleaned three times in this manner.

[0034] Heating and melting: When the furnace temperature is 1550℃~1580℃, slowly add carbon powder particles and alloy particles through the secondary feeding hopper. Then, start the stirring device to stir the crucible at a rate of 30 rpm until all materials are dissolved. Control the steel pouring temperature to 1500℃~1550℃ and pour it into a circular copper mold with a water circulation device in a vacuum high-frequency induction melting furnace. After cooling, break the vacuum and remove the steel billet from the furnace.

[0035] S3. Annealing treatment: Heat the steel billet obtained in step S2 to 700℃~850℃ at a rate of 6℃ / min~8℃ / min, hold it at that temperature for 60~90min, and then slowly cool it in the furnace to 450℃~500℃. Remove it from the furnace and air cool it to room temperature.

[0036] S4. Hot Forging of Steel Billets: The steel billets obtained in step S3 are heated to the initial forging temperature of 1060℃ at a rate of 6℃ / min to 8℃ / min, held at this temperature for 50 to 70 minutes, and then forged. The billets are then uplifted four times with a 120kg to 200kg hammer, with the downward pressure not exceeding 1 / 4 of the ingot height; and then drawn four times with a 120kg to 200kg hammer, with the drawing length not exceeding 1 / 4 of the ingot length. Finally, the billets are uplifted four times with a 350kg to 600kg hammer, with the downward pressure not exceeding 1 / 3 of the ingot height; and then drawn four times with a 350kg to 600kg hammer, with the drawing length not exceeding 1 / 3 of the ingot length. The final forging temperature is controlled at 940℃, and then cooled to room temperature in the furnace.

[0037] S5. Quenching treatment of steel billet: The steel billet obtained in step S4 is heated to 900℃~950℃ at a rate of 6℃ / min~8℃ / min, held for 60~90min, and then oil-cooled to room temperature; the quenching oil used is mineral oil with 0.5wt.% of the cooling agent petroleum resin and 1wt.% of industrial sodium chloride added.

[0038] S6. Tempering treatment of steel billet: Heat the steel billet obtained in step S5 to 230℃~280℃ at a rate of 3℃ / min~5℃ / min, hold for 70~90min, remove from the furnace and air cool to room temperature to obtain high chromium and high vanadium high-speed steel.

[0039] Example 2:

[0040] The composition of high-chromium, high-vanadium high-speed steel by mass percentage is: carbon 1.03%, vanadium 3.5%, chromium 8.4%, molybdenum 2.1%, manganese 0.61%, silicon 0.75%, nickel 0.5%, sulfur 0.015%, phosphorus 0.021%, with the balance being iron;

[0041] The preparation method of the above-mentioned high-chromium, high-vanadium high-speed steel includes the following steps:

[0042] S1. Raw materials with a purity of 99.5% are selected according to the above composition ratio of high-chromium and high-vanadium high-speed steel. Iron rods, carbon powder particles with a particle size of 0.5mm to 0.8mm, ferrovanadium particles containing 60% vanadium, ferrochrome particles containing 70% chromium, ferromolybdenum particles containing 60% molybdenum, ferromanganese sheets containing 80% manganese, ferrosilicon blocks containing 50% silicon, and nickel powder with a purity of 98%; the alloy particles used have a size of 3mm to 10mm. The alloy particles refer to: ferrovanadium particles containing 60% vanadium, ferrochrome particles containing 70% chromium, ferromolybdenum particles containing 60% molybdenum, ferromanganese sheets containing 80% manganese, ferrosilicon blocks containing 50% silicon, and nickel powder with a purity of 98%.

[0043] S2. The raw materials taken in step S1 are smelted using a vacuum high-frequency induction melting furnace with argon protection: First, the cooling water system of the vacuum high-frequency induction melting furnace is turned on. The pre-weighed and calculated iron bars are placed into the crucible inside the furnace, and the proportioned carbon powder particles and alloy particles are placed into the secondary feeding bin for later use. The furnace door is closed and a vacuum of 1×10⁻⁶ is drawn. -1 The pressure is increased to MPa, then the vacuum system is shut off, and argon gas is introduced into the furnace cavity to -0.05MPa to 0.01MPa. After that, the argon gas device is shut off and the vacuum is evacuated. The furnace is cleaned three times in this manner.

[0044] Heating and smelting: When the furnace temperature is between 1500℃ and 1580℃, slowly add carbon powder particles and alloy particles through the secondary feeding hopper. Then, start the stirring device to stir the crucible at a rate of 30 rpm until all materials are dissolved. Control the steel pouring temperature to 1500℃ to 1550℃ and pour it into a circular copper mold with a water circulation device in a vacuum high-frequency induction melting furnace. After cooling, break the vacuum and remove the steel billet from the furnace.

[0045] S3. Annealing treatment: Heat the steel billet obtained in step S2 to 700℃~850℃ at a rate of 6℃ / min~8℃ / min, hold it at that temperature for 60~90min, and then slowly cool it in the furnace to 450℃~500℃. Remove it from the furnace and air cool it to room temperature.

[0046] S4. Hot Forging of Steel Billets: The steel billets obtained in step S3 are heated to the initial forging temperature of 1060℃ at a rate of 6℃ / min to 8℃ / min, held at this temperature for 50 to 70 minutes, and then forged. The billets are then uplifted four times with a 120kg to 200kg hammer, with the downward pressure not exceeding 1 / 4 of the ingot height; and then drawn four times with a 120kg to 200kg hammer, with the drawing length not exceeding 1 / 4 of the ingot length. Finally, the billets are uplifted four times with a 350kg to 600kg hammer, with the downward pressure not exceeding 1 / 3 of the ingot height; and then drawn four times with a 350kg to 600kg hammer, with the drawing length not exceeding 1 / 3 of the ingot length. The final forging temperature is controlled at 940℃, and then cooled to room temperature in the furnace.

[0047] S5. Quenching treatment of steel billet: The steel billet obtained in step S4 is heated to 900℃~950℃ at a rate of 6℃ / min~8℃ / min, held for 60~90min, and then oil-cooled to room temperature; the quenching oil used is mineral oil with 0.5wt.% of the cooling agent petroleum resin and 1wt.% of industrial sodium chloride added.

[0048] S6. Tempering treatment of steel billet: Heat the steel billet obtained in step S5 to 230℃~280℃ at a rate of 3℃ / min~5℃ / min, hold for 70~90min, remove from the furnace and air cool to room temperature to obtain high chromium and high vanadium high-speed steel.

[0049] Example 3:

[0050] The composition of high-chromium, high-vanadium high-speed steel by mass percentage is as follows: carbon 1.51%, vanadium 6%, chromium 4.97%, molybdenum 0.52%, manganese 0.9%, silicon 0.83%, nickel 0.68%, sulfur 0.013%, phosphorus 0.023%, with the balance being iron.

[0051] The preparation method of the above-mentioned high-chromium, high-vanadium high-speed steel includes the following steps:

[0052] S1. Raw materials are selected according to the composition ratio of high-chromium, high-vanadium high-speed steel: purity is 99.5%. Iron rods, carbon powder particles with a particle size of 0.5mm to 0.8mm, ferrovanadium particles containing 60% vanadium, ferrochrome particles containing 70% chromium, ferromolybdenum particles containing 60% molybdenum, ferromanganese sheets containing 80% manganese, ferrosilicon blocks containing 50% silicon, and nickel powder with a purity of 98%; the alloy particles used have a size of 3mm to 10mm. The alloy particles refer to: ferrovanadium particles containing 60% vanadium, ferrochrome particles containing 70% chromium, ferromolybdenum particles containing 60% molybdenum, ferromanganese sheets containing 80% manganese, ferrosilicon blocks containing 50% silicon, and nickel powder with a purity of 98%.

[0053] S2. The raw materials taken in step S1 are smelted using a vacuum high-frequency induction melting furnace with argon protection: First, the cooling water system of the vacuum high-frequency induction melting furnace is turned on. The pre-weighed and calculated iron bars are placed into the crucible inside the furnace, and the proportioned carbon powder particles and alloy particles are placed into the secondary feeding bin for later use. The furnace door is closed and a vacuum of 1×10⁻⁶ is drawn. -1 The pressure is increased to MPa, then the vacuum system is shut off, and argon gas is introduced into the furnace cavity to -0.05MPa to 0.01MPa. After that, the argon gas device is shut off and the vacuum is evacuated. The furnace is cleaned three times in this manner.

[0054] Heating and smelting: When the furnace temperature is between 1500℃ and 1580℃, slowly add carbon powder particles and alloy particles through the secondary feeding hopper. Then, start the stirring device to stir the crucible at a rate of 30 rpm until all materials are dissolved. Control the steel pouring temperature to 1500℃ to 1550℃ and pour it into a circular copper mold with a water circulation device in a vacuum high-frequency induction melting furnace. After cooling, break the vacuum and remove the steel billet from the furnace.

[0055] S3. Annealing treatment: Heat the steel billet obtained in step S2 to 700℃~850℃ at a rate of 6℃ / min~8℃ / min, hold it at that temperature for 60~90min, and then slowly cool it in the furnace to 450℃~500℃. Remove it from the furnace and air cool it to room temperature.

[0056] S4. Hot Forging of Steel Billets: The steel billets obtained in step S3 are heated to the initial forging temperature of 1100℃ at a rate of 6℃ / min to 8℃ / min, held at this temperature for 50 to 70 minutes, and then forged. The billets are then uplifted four times with a 120kg to 200kg hammer, with the downward pressure not exceeding 1 / 4 of the ingot height; and then drawn four times with a 120kg to 200kg hammer, with the drawing length not exceeding 1 / 4 of the ingot length. Finally, the billets are uplifted four times with a 350kg to 600kg hammer, with the downward pressure not exceeding 1 / 3 of the ingot height; and then drawn four times with a 350kg to 600kg hammer, with the drawing length not exceeding 1 / 3 of the ingot length. The final forging temperature is controlled at 920℃, and then cooled to room temperature in the furnace.

[0057] S5. Quenching treatment of steel billet: The steel billet obtained in step S4 is heated to 900℃~950℃ at a rate of 6℃ / min~8℃ / min, held for 60~90min, and then oil-cooled to room temperature; the quenching oil used is mineral oil with 0.5wt.% of the cooling agent petroleum resin and 1wt.% of industrial sodium chloride added.

[0058] S6. Tempering treatment of steel billet: Heat the steel billet obtained in step S5 to 230℃~280℃ at a rate of 3℃ / min~5℃ / min, hold for 70~90min, remove from the furnace and air cool to room temperature to obtain high chromium and high vanadium high-speed steel.

[0059] Figure 4 This is a TEM image of the high-chromium, high-vanadium high-speed steel obtained in this embodiment. As can be seen from the image, the carbide MC is evenly distributed in the steel matrix, and its particle size is relatively uniform, with a particle size of about 0.5 to 2 μm.

[0060] Hardness, impact toughness, room temperature abrasive wear, and high-temperature friction and wear tests were conducted on the high-chromium, high-vanadium high-speed steel samples prepared in Examples 1-3 and existing cast V10 high-speed steel, respectively. The impact toughness test specimens used in this invention were unnotched specimens. The room temperature abrasive wear specimens were round bars with a diameter of 4 mm and a length of 15 mm. The weight loss of the three high-speed steel samples prepared in Examples 1-3 and the cast V10 high-speed steel under the same wear conditions over the same time period was compared.

[0061] High-chromium, high-vanadium high-speed steel samples subjected to high-temperature friction and wear are shown below. Figure 1 ,and Figure 1 The bottom rotating sample block of the high-speed steel sample shown is a disk made of Inconel 625 alloy (nickel-based wrought superalloy). The high-temperature friction and wear test temperature is 620℃. The weight loss of the three high-speed steel samples prepared in Examples 1-3 and the cast V10 high-speed steel under the same wear conditions for the same time is compared. The test results are shown in Table 1.

[0062] Table 1. Performance test results of high-chromium, high-vanadium high-speed steel prepared in Examples 1-3 and as-cast high-vanadium high-speed steel.

[0063]

[0064] As shown in Table 1, the Rockwell hardness (HRC) of the high-chromium, high-vanadium high-speed steel prepared by this invention is not significantly different from that of the as-cast V10 high-speed steel. Compared with the as-cast V10 high-speed steel, the high-chromium, high-vanadium high-speed steel prepared by this invention exhibits higher impact toughness, lower weight loss during room-temperature abrasive wear, and lower weight loss during high-temperature frictional wear. This indicates that the high-chromium, high-vanadium high-speed steel prepared by this invention has higher wear resistance and better impact toughness, especially excellent high-temperature wear resistance.

[0065] The above three embodiments are merely individual examples of the present invention and are not intended to limit the invention. The high-chromium, high-vanadium high-speed steel of the present invention, while maintaining a hardness of HRC60-68, exhibits significantly improved impact toughness, reaching 16-25 J / cm². 2 Compared with traditional cast high-vanadium high-speed steel, its wear resistance at both room temperature and high temperature is improved by more than 60%.

[0066] The above description is merely an embodiment of the present invention and is not intended to limit the present invention in any way. The present invention can also have other embodiments based on the above structure and function, which will not be listed hereafter. Therefore, any simple modifications, equivalent changes, and alterations made by those skilled in the art to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A high-chromium high-vanadium high-speed steel, characterized in that The components include, by 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 iron, the high-chromium high-vanadium high-speed steel having a Rockwell hardness HRC of 60~68, an impact toughness of 15.2 J / cm 2 or 15.4 J / cm 2 or 16~16.7 J / cm 2 , and a wear resistance at normal and high temperatures increased by more than 60% than that of cast V10 high-speed steel.

2. The high-chromium high-vanadium high-speed steel according to claim 1, characterized in that The components include, by mass percentage: carbon 1.51%, vanadium 6%, chromium 4.97%, molybdenum 0.52%, manganese 0.9%, silicon 0.83%, nickel 0.68%, sulfur 0.013%, phosphorus 0.023%, and the balance iron, the impact toughness of the high-chromium high-vanadium high-speed steel being 15.2 J / cm 2 or 15.4 J / cm 2 .

3. The high-chromium high-vanadium high-speed steel of claim 1, wherein The components include, by mass percentage: carbon 1.03%, vanadium 3.5%, chromium 8.4%, molybdenum 2.1%, manganese 0.61%, silicon 0.75%, nickel 0.5%, sulfur 0.015%, phosphorus 0.021%, and the balance iron, and the impact toughness of the high-chromium high-vanadium high-speed steel is 16.7 J / cm 2 .

4. The high-chromium high-vanadium high-speed steel according to any one of claims 1 to 3, characterized in that The raw materials include: iron rods with a purity of 99.5% and a diameter of 30mm-80mm, carbon powder particles with a particle size of 0.5mm-0.8mm, vanadium-iron particles containing 60% vanadium, chromium-iron particles containing 70% chromium, molybdenum-iron particles containing 60% molybdenum, manganese-iron pieces containing 80% manganese, silicon-iron blocks containing 50% silicon, nickel powder with a purity of 98%, and alloy particles with a size of 3mm-10mm; the alloy particles refer to vanadium-iron particles containing 60% vanadium, chromium-iron particles containing 70% chromium, molybdenum-iron particles containing 60% molybdenum, manganese-iron pieces containing 80% manganese, silicon-iron blocks containing 50% silicon, and nickel powder with a purity of 98%.

5. A method for producing a high-chromium high-vanadium high-speed steel, characterized by The method comprises the following steps: S1, taking raw materials according to the mass percentage of the composition of high-chromium high-vanadium high-speed steel; the composition of high-chromium high-vanadium high-speed steel is as follows according to the 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 raw materials include: iron rods with a purity of 99.5% and a diameter of 30mm-80mm, carbon powder particles with a particle size of 0.5mm-0.8mm, vanadium-iron particles containing 60% vanadium, chromium-iron particles containing 70% chromium, molybdenum-iron particles containing 60% molybdenum, manganese-iron pieces containing 80% manganese, silicon-iron blocks containing 50% silicon, and nickel powder with a purity of 98%; S2, the raw materials taken in step S1 are smelted by a vacuum high-frequency induction smelting furnace with argon protection: first, the cooling water system of the vacuum high-frequency induction smelting furnace is opened, the iron bar weighed and calculated in advance is placed into the crucible in the furnace, and the carbon powder particles and alloy particles matched are placed into the secondary feeding bin for standby, the furnace door is closed, vacuum is extracted to 1x10 -1 MPa, then the vacuum system is closed, argon is filled into the furnace cavity to -0.05 MPa~0.01 MPa, then the argon device is closed and vacuum is extracted, and the furnace is washed in this way for three times; Heating and smelting: when the temperature in the furnace is 1550℃-1580℃, slowly add carbon powder particles and alloy particles to the second charging bin, then start the stirring device to stir the crucible at a speed of 30r / min until the materials are completely melted; control the pouring temperature of the molten steel to be 1500℃-1550℃, pour into a circular copper mold with a water circulating device in a vacuum high-frequency induction melting furnace, and after cooling, break the vacuum to get the billet; S3, annealing treatment: heat the billet obtained in step S2 to 700℃-850℃ at a rate of 6℃ / min-8℃ / min, keep it for 60-90min, then slowly cool it to 450℃-500℃ in the furnace, and take it out to air cool to room temperature; S4, hot forging of the billet: heat the billet obtained in step S3 to the initial forging temperature of 1050℃-1100℃ at a rate of 6℃ / min-8℃ / min, keep it for 50-70min, and take it out to forge; the forging includes: roughing with a hammer of 120kg-200kg for 4 times, the downward displacement being not more than 1 / 4 of the height of the ingot, elongating with a hammer of 120kg-200kg for 4 times, the elongation being not more than 1 / 4 of the length of the ingot; roughing with a hammer of 350kg-600kg for 4 times, the downward displacement being not more than 1 / 3 of the height of the ingot, elongating with a hammer of 350kg-600kg for 4 times, the elongation being not more than 1 / 3 of the length of the ingot; control the final forging temperature to be 900℃-950℃, and then cool it to room temperature in the furnace; S5, quenching treatment of the billet: heat the billet obtained in step S4 to 900℃-950℃ at a rate of 6℃ / min-8℃ / min, keep it for 60-90min, and oil cool it to room temperature; S6, the billet is heated to 230-280℃ at a rate of 3-5℃ / min, and kept for 70-90 min, and then air cooled to room temperature to obtain the high-chromium high-vanadium high-speed steel.

6. The method of producing high-chromium high-vanadium high-speed steel according to claim 5, characterized by The composition of the high-chromium high-vanadium high-speed steel in step S1 is as follows in terms of mass percentage: carbon 1.51%, vanadium 6%, chromium 4.97%, molybdenum 0.52%, manganese 0.9%, silicon 0.83%, nickel 0.68%, sulfur 0.013%, phosphorus 0.023%, and the balance of iron. The impact toughness of the high-chromium high-vanadium high-speed steel obtained in the final step S6 is 15.2 J / cm 2 or 15.4 J / cm 2 ; Alternatively, the composition of the high-chromium high-vanadium high-speed steel is as follows in terms of mass percentage: carbon 1.03%, vanadium 3.5%, chromium 8.4%, molybdenum 2.1%, manganese 0.61%, silicon 0.75%, nickel 0.5%, sulfur 0.015%, phosphorus 0.021%, and the balance of iron. The impact toughness of the high-chromium high-vanadium high-speed steel obtained in the final step S6 is 16.7 J / cm 2 .

7. The method of producing high-chromium high-vanadium high-speed steel according to claim 5, characterized by The initial forging temperature in step S4 is 1060℃, and the final forging temperature is 940℃.

8. The method of producing high-chromium high-vanadium high-speed steel according to claim 5, characterized by The quenching oil used in step S5 is mineral oil containing 0.5wt.% of a chiller and 1wt.% of sodium salt.

9. The method of producing high-chromium high-vanadium high-speed steel according to claim 8, characterized by The chiller is selected from petroleum resin, and the sodium salt is selected from industrial sodium chloride.

10. The method of producing high-chromium high-vanadium high-speed steel according to claim 5, characterized by The prepared high-chromium high-vanadium high-speed steel has a Rockwell hardness HRC of 60-68, and an impact toughness of 15.2 J / cm 2 or 15.4 J / cm 2 or 16-16.7 J / cm 2 The wear resistance at room temperature and high temperature is increased by more than 60% than that of the as-cast V10 high-speed steel.

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