Melt Impact Molding Method for Controlling the Second Phase Morphology of Alloy Ingots

Abstract

This application provides a method for refining carbides of high-carbon high-alloy steel and relates to the field of manufacturing methods for alloy steel. The method for refining carbides of high-carbon high-alloy steel includes the steps of preparing raw materials according to the chemical element composition of high-carbon high-alloy steel, smelting to obtain high-carbon high-alloy molten steel, superheating the high-carbon high-alloy molten steel to Tm+(50~100)°C to obtain high-carbon high-alloy molten metal, depositing the high-carbon high-alloy molten metal into a preset water-cooled copper mold at a rate of 30~160 g / s through an inert gas, and solidifying and forming to obtain a high-carbon high-alloy ingot, and performing a heat treatment process on the high-carbon high-alloy ingot. According to the method for refining carbides of high-carbon high-alloy steel of this application, high-carbon high-alloy steel with a dense structure and fine carbides can be obtained.

Description

Technical Field

[0001] This application claims the priority of the Chinese patent application with the application number CN 202210485310.1, titled "Method for Refining Carbides of High-Carbon High-Alloy Steel", filed with the China National Intellectual Property Administration on May 6, 2022, and all its contents are incorporated herein by reference. The present invention relates to the field of methods for manufacturing alloy steel, and specifically to a method for refining carbides of high-carbon high-alloy steel.

Background Art

[0002] Currently, due to the high carbon content and high alloy element content, high-carbon high-alloy steel is prone to generating coarse eutectic carbides, severe segregation, non-uniform structure, and the mechanical properties and wear resistance of high-carbon high-alloy steel are significantly restricted. The manufacturing methods of high-carbon high-alloy steel mainly include traditional casting methods, electroslag remelting methods, injection molding methods, powder metallurgy methods, etc. Among the above manufacturing methods, traditional casting methods and electroslag remelting methods are widely used in mass industrial production, but they cannot effectively solve the problem of coarse carbides in the structure and have severe segregation. Injection molding is a rapid solidification technology that uses refined liquid metal, sprays it into droplet jets, deposits semi-solidified droplet particles on a substrate, and rapidly solidifies them to form a casting. The injection molding method can achieve refinement of the structure of the metal material, homogenization of the composition, and elimination of macrosegregation. However, in this method, the degree of structure refinement is low, excessive scattering of spray droplets is likely to occur, the yield is low, and the formed metal material has inherent pores due to its loose structure.

Summary of the Invention

Problems to be Solved by the Invention

[0003] An object of the present invention is to provide a method for refining carbides of high-carbon high-alloy steel that can obtain high-carbon high-alloy steel with a dense structure and fine carbides.

Means for Solving the Problems

[0004] The present invention provides a method for refining carbides of high-carbon high-alloy steel, preparing raw materials according to the chemical element composition of high-carbon high-alloy steel, and smelting to obtain high-carbon high-alloy molten steel; superheating the high-carbon high-alloy molten steel to Tm+(50~100)°C to obtain a high-carbon high-alloy molten bath, and depositing the high-carbon high-alloy molten bath into a preset water-cooled copper mold at a speed of 30~160 g / s through an inert gas, and solidifying and forming to obtain a high-carbon high-alloy ingot; performing a heat treatment process on the high-carbon high-alloy ingot.

[0005] In the above technical solution, the alloy molten steel is superheated. After the alloy molten bath reaches a predetermined temperature, under the propulsion of the inert gas, the molten bath is deposited into the water-cooled copper mold at a certain speed, formed and solidified to form a high-carbon high-alloy ingot with fine carbides. Then, through the subsequent heat treatment system, the microstructure and distribution of the high-carbon high-alloy steel further change, and the service life is improved.

[0006] Among them, the degree of superheat should not be too high. If it is too high, it will lead to the coarsening of the solidification structure. The degree of superheat should not be too low. If it is too low, the fluidity will become poor, it will be difficult to obtain a rapid impact, and the nozzle is prone to clogging.

[0007] Here, the molten bath is impacted and formed at a certain speed. Due to the impact, the crystal grains are crushed, the primary carbides are crushed, the crystal grains and carbides can be refined, the generation of pores is greatly reduced, the utilization rate of the molten bath is high, there is no waste of the molten bath. The biggest difference between the melt impact method and the conventional injection molding method is that the fine structure of the formed ingot is dense and uniform, the carbides are fine. During the subsequent heat treatment process, the crystal grains are recrystallized based on the dislocations and crushed primary carbides to realize fine crystal grains, fine carbides, and uniform distribution. As a result, the strength, toughness, and wear resistance of the high-carbon high-alloy steel are improved, and the service life is extended.

[0008] Optionally, the chemical element composition of the high-carbon high-alloy steel is, by weight percentage, C: 1.5 - 2.5%, W: 2.5 - 10%, Mo: 3 - 7%, Cr: 4 - 6%, V: 2 - 10%, Si: 0.3 - 0.6%, Mn: 0.3 - 0.8%, and the balance is Fe.

[0009] In the above technical solution, the carbon content is controlled to be 1.5 - 2.5%. A part of it penetrates into the matrix to cause solid solution strengthening, ensuring the strength and hardness of the matrix. The other part combines with alloying elements to form various types of alloy carbides. If the carbon content is insufficient, the secondary hardenability is insufficient, the strength and hardness of the matrix decrease, and at the same time, the number of primary carbides also relatively decreases, resulting in a decrease in the wear resistance and service life of the steel. Conversely, if the carbon content is too high, a large amount of alloy carbides are formed, and the non-uniformity of the carbides increases significantly, ultimately leading to a significant decrease in the plasticity, toughness, and forging properties of the steel.

[0010] The tungsten content is controlled to be 2.5 - 10%, forming a certain amount of insoluble primary carbides, improving the wear resistance of the steel, and also preventing the growth of crystal grains during quenching, thereby enabling the refinement of crystal grains. If the tungsten content is too high, the density increases, and during solidification, there is a tendency for coarse fishbone-shaped M 6 C eutectic carbides to precipitate, which has an adverse effect on plasticity.

[0011] The molybdenum content is controlled to be 3 - 7%. It not only dissolves in the matrix to achieve solid solution strengthening but also can form M 2 C and M 6 C carbides together with carbon. Its role is similar to that of tungsten in high-carbon high-alloy steel.

[0012] The chromium content is controlled to be 4 - 6%. Cr is one of the most beneficial elements for improving hardenability. When combined with elements such as W, Mo, V, etc., it can reduce the mismatch between the secondary carbide precipitation phase and the matrix, lower the nucleation activation energy, promote the concentrated dispersion and precipitation of a large amount of secondary carbides, and greatly contribute to secondary hardening. If the chromium content is too low, it will have a significant impact on the hardenability of high-carbon high-alloy steel. Especially in the case of high-carbon high-alloy steel, hardenability is very important, and only an appropriate chromium content can ensure sufficient hardenability of high-carbon high-alloy steel. If the chromium content is too high, temper brittleness of high-alloy steel is likely to occur, which has an adverse effect on plasticity.

[0013] The vanadium content is controlled to be 2 - 10%. Part of it is dissolved in the matrix, and the other part forms primary MC carbides with C. Vanadium dissolved in the matrix can significantly enhance the secondary hardening effect of the steel, and undissolved VC carbides can prevent the growth of particles during quenching and heating, and can significantly improve the wear resistance of the steel. If the vanadium content is too low, it will have an adverse effect on the hardness and wear resistance of high-carbon high-alloy steel. If the vanadium content is too high, a large amount of MC carbides will be formed. MC carbides have very high hardness and brittleness and do not contribute to the plasticity and toughness of the steel.

[0014] The manganese content is controlled to be 0.3 - 0.8%. Manganese exhibits a good deoxidation and desulfurization effect in the low content range, contributes to the strength and wear resistance of high-alloy steel, and improves hardenability. Since manganese can remove or weaken the hot brittleness of steel caused by sulfur, the hot working performance of high-alloy steel is improved. As the manganese content increases, the retained austenite content increases, and the thermal stability and hardness of high-carbon high-alloy steel decrease.

[0015] The silicon content is controlled to be 0.3 - 0.6%. Silicon strengthens the matrix, improves the strength, hardness, and hardenability of high-alloy steel, can suppress the formation of M 3 C, and can refine M 3 C, and transform M 2 C to MC and M 7 C 3Conversion to etc. can be promoted. If the silicon content is too high, the formation of primary coarse MC is easily promoted, the decarburization tendency of high-alloy steel increases, and the tempering stability of high-alloy steel decreases.

[0016] Optionally, the heat treatment process includes a high-temperature solution treatment, a low-temperature interrupted quenching, and a tempering treatment that are carried out sequentially. The high-temperature solution treatment is maintained at 900-1050 °C for 15-60 minutes, the low-temperature interrupted quenching is maintained at 700-860 °C for 1-2 hours, and the tempering treatment is maintained at 520-580 °C for 3-4 hours.

[0017] In the above technical solution, the heat treatment process of the ingot is a further operation and continuation of refining carbides, and inherits the microscopic structure of the fine carbides of the ingot to the final state after heat treatment. First, a high-temperature solution treatment is performed on the high-carbon high-alloy ingot to sufficiently dissolve the fine carbides in the matrix, remove and dissolve individual coarse residual carbides. Since the carbides of the ingot are fine, the use of high-temperature solution can shorten the temperature holding time and save energy. The purpose of interrupted quenching is to refine matrix particles and spheroidize carbides. Since the carbides are sufficiently dissolved after high-temperature solution, the subsequent interrupted quenching temperature can be lowered, and a high austenitizing temperature is not required. The low interrupted quenching temperature avoids the accumulation and growth of carbides. The tempering treatment aims to release residual stress while adjusting the hardness and toughness of high-carbon high-alloy steel.

[0018] Optionally, after the high-temperature solution treatment is completed, oil quenching is carried out to room temperature, and then low-temperature interrupted quenching is performed, and / or after the low-temperature interrupted quenching is completed, water quenching is carried out to the martensite transformation point, oil quenching is carried out to room temperature, and a tempering treatment is performed.

[0019] In the above technical solution, after the high-temperature solution treatment reaches the preset holding time, it is taken out of the furnace and oil quenched to room temperature. After the low-temperature interrupted quenching is completed, it is rapidly water quenched to the M point (martensite transformation point) to maintain the fine size of the carbides and avoid the complete growth of the carbides by slow cooling. At the same time, the rapid cooling improves the distribution of dislocations, enhances the strength of the matrix, and the oil quenching after the M point is to avoid quenching deformation, cracking, etc. after reaching room temperature.

[0020] Optionally, the heat treatment method includes evacuating the chamber containing the high-carbon high-alloy molten steel to 100-400 Pa, filling it with an inert gas for protection, and then heating the high-carbon high-alloy molten steel to obtain a high-carbon high-alloy molten bath.

[0021] Optionally, the heat treatment is carried out by the method of coil heating.

[0022] Optionally, the method of molten bath deposition includes filling an inert gas for protection, heating the high-carbon high-alloy molten steel to obtain a high-carbon high-alloy molten bath, and then continuously filling an inert gas to promote the injection of the high-carbon high-alloy molten bath into the external chamber.

[0023] In the above technical solution, after evacuating the chamber, it is filled with an inert atmosphere for protection. When the molten bath reaches the superheat temperature, an inert gas flow is filled into the molten bath, so that a certain pressure difference is generated between the molten bath and the external chamber, and the molten bath is rapidly injected. Since the injection is mainly controlled by the air flow, the realization and operation are simple.

[0024] Optionally, the high-carbon high-alloy molten bath is deposited under the action of a pressure difference, and the pressure difference is 0.05-0.25 MPa.

[0025] In the above technical solution, if the pressure difference is too large, molten bath splashing is likely to occur. If it is less than this pressure difference range, an effective impact force cannot be formed, and the coarse eutectic structure cannot be effectively refined.

[0026] Optionally, the distance between the nozzle outlet of the chamber where the high-carbon high-alloy molten metal is located and the water-cooled copper mold is 11 to 20 cm, and / or the water outlet temperature of the water-cooled copper mold is 30 to 45 °C.

[0027] In the above technical solution, if the injection distance is too small, the alloy molten steel is likely to scatter, and if the injection distance is too large, the effective impact force cannot be maintained.

[0028] Optionally, the outlet shape of the nozzle is a round hole type or a slit type, and all the nozzles are arranged in an array.

Brief Description of the Drawings

[0029] To more clearly explain the technical solution of the embodiments of the present application, the following briefly describes the attached drawings used in the embodiments of the present application. The following drawings only show specific embodiments of the present application and are therefore not considered to limit the scope. It should be understood that for those skilled in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0030]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0031] The applicant has discovered that due to the high carbon content and alloying elements in high-carbon high-alloy steel, it is easy to form coarse eutectic carbides and the segregation is serious. The microscopic structure of the current castings (castings obtained by forming) of high-carbon high-alloy steel is very non-uniform and mainly composed of martensite, retained austenite and various carbides. Various carbides (the most common MC, M2 C, M 6 C, etc. are unevenly distributed, with different shapes. In particular, coarse network eutectic carbides are distributed at grain boundaries, splitting the matrix and degrading service performance. In the case of castings of high-carbon high-alloy steel, refining carbides and making them uniformly distributed is particularly important for subsequent thermomechanical deformation and improvement of mechanical properties. Coarse network eutectic carbides in castings are broken by subsequent processes such as forging and rolling, thus having a significant impact on mechanical properties. It is difficult to uniformly refine and disperse carbides even after forging or rolling processes, and the cost also increases.

[0032] Furthermore, most high-carbon high-alloy steel products are mainly castings, that is, there is no subsequent thermomechanical deformation, and only heat treatment is carried out. The distribution and morphology of coarse carbides cannot be changed by heat treatment. For example, ingots manufactured by existing injection molding techniques have inherent pores. In the case of cast alloy steel, since there is no subsequent forging process, pores still exist in the ingot after heat treatment, and the lifespan is significantly reduced. Therefore, refining coarse eutectic carbides so that high-carbon high-alloy steel castings have an initial fine carbide microstructure is very important for improving mechanical properties.

[0033] This application utilizes the rapid impact of liquid flow, the liquid-solid interface of a self-stirring melting pool, and high-speed impact force to break dendritic crystals, increase nucleation sites, create conditions for grain refinement, and, in combination with specific heat treatment processes, significantly effect the refinement of primary carbides in high-carbon high-alloy steel ingots.

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are clearly and completely described below. For conditions not specifically described in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. All reagents or equipment used without manufacturer instructions are ordinary commercially available products.

[0035] The following will describe in detail a method for refining carbides of a high-carbon high-alloy steel according to an embodiment of the present application.

[0036] The embodiment of the present application provides a method for refining carbides of a high-carbon high-alloy steel, mainly including the production of a high-carbon high-alloy ingot by the melt impact method and a heat treatment process, and includes the following steps. (1) Production of a high-carbon high-alloy ingot by the melt impact method S1. According to the chemical element composition of the high-carbon high-alloy steel, prepare raw materials so that they contain, by weight percentage, C: 1.5 - 2.5%, W: 2.5 - 10%, Mo: 3 - 7%, Cr: 4 - 6%, V: 2 - 10%, Si: 0.3 - 0.6%, Mn: 0.3 - 0.8%, and the balance Fe. Then smelt to obtain a high-carbon high-alloy molten steel. S2. Evacuate the chamber containing the high-carbon high-alloy molten steel to 100 - 400 Pa, fill it with an inert gas for protection to make the whole chamber in an inert atmosphere protection state. Then, use the coil heating method to heat the high-carbon high-alloy molten steel to a temperature range 50 - 100 °C higher than the melting point, that is, superheat it to Tm+(50 - 100) °C to obtain a high-carbon high-alloy molten bath. Continuously fill the inert gas so that a pressure difference of 0.05 - 0.25 MPa is formed between the chamber containing the high-carbon high-alloy molten steel and the external chamber. Thereby, the high-carbon high-alloy molten bath is injected into the external chamber at a speed of 30 - 160 g / s under the pressure difference and deposited in a preset water-cooled copper mold. The distance between the nozzle outlet of the chamber where the high-carbon high-alloy molten bath is located and the water-cooled copper mold is 11 - 20 cm, and the water outlet temperature of the water-cooled copper mold is 30 - 45 °C. Solidify and form to obtain a high-carbon high-alloy ingot.

[0037] In the embodiment of the present application, the raw materials are placed in a crucible and melted using an intermediate frequency induction furnace to obtain a high-carbon high-alloy molten steel. Moreover, the chamber of the intermediate frequency induction furnace is in a sealed state, and the coil is heated to become molten steel and further superheated to become molten metal. There is a graphite nozzle at the bottom of the crucible, and the outlet shape of the nozzle is a round hole type or a slit type. All the nozzles are arranged in an array, and the molten metal passes through the nozzle due to the pressure difference and deposits in the water-cooled copper mold at a certain speed, forms and solidifies, and a high-carbon alloy ingot with fine carbides is obtained.

[0038] (2) Heat treatment process S3. Perform a high-temperature solution treatment on the high-carbon high-alloy ingot, hold it at 900 - 1050 °C for 15 - 60 minutes, and then oil quench it to room temperature. S4. Perform a low-temperature interrupted quenching on the ingot after step S3, hold it at 700 - 860 °C for 1 - 2 hours, water quench it to the martensite transformation point (M point), and then oil quench it to room temperature. S5. Perform a tempering treatment on the ingot after step S4, hold it at 520 - 580 °C for 3 - 4 hours to obtain a high-carbon high-alloy steel.

[0039] Example The features and performance of the present application will be further described in detail below with reference to the examples.

[0040] Example 1 This example provides a high-carbon high-alloy steel, and its manufacturing process is as follows. S1. According to the chemical element composition of the high-carbon high-alloy steel C: 2.5%, W: 4.1%, Mo: 2.9%, Cr: 5.0%, V: 8.2%, Si: 0.5%, Mn: 0.3%, and the balance Fe, prepare the raw materials, place them in a crucible, and smelt them at a melting point temperature of 1398 °C using an intermediate frequency induction furnace to obtain a high-carbon high-alloy molten steel. S2. Evacuate the chamber of the medium-frequency induction furnace to 200 Pa, then fill it with an inert gas so that the whole chamber is in a state of being protected by an inert atmosphere. Next, heat the high-carbon high-alloy molten steel and superheat it to 1450 °C, i.e., Tm + 52 °C, to obtain a high-carbon high-alloy molten metal. Keep filling the inert gas so that a pressure difference of 0.15 MPa is formed between the chamber and the external chamber. As a result, the high-carbon high-alloy molten metal in the crucible is injected from the nozzle at the bottom of the crucible into the external chamber at a speed of 100 g / s under the pressure difference and deposited in a pre-set water-cooled copper mold. The distance between the nozzle outlet and the water-cooled copper mold is 15 cm, and the water outlet temperature of the water-cooled copper mold is 40 °C. After solidification forming, a high-carbon high-alloy ingot is obtained. S3. Perform a high-temperature solution treatment on the high-carbon high-alloy ingot, hold it at 1000 °C for 30 minutes, and then perform oil quenching to room temperature. S4. Perform a low-temperature interrupted quenching on the ingot after step S3, hold it at 800 °C for 1.5 hours, perform water quenching to the martensite transformation point (M point), and then perform oil quenching to room temperature. S5. Perform a tempering treatment on the ingot after step S4, hold it at 550 °C for 3.5 hours to obtain high-carbon high-alloy steel.

[0041] Example 2 This example provides high-carbon high-alloy steel. The difference in the manufacturing process from Example 1 is that the pressure difference is controlled to 0.25 MPa.

[0042] Example 3 This example provides high-carbon high-alloy steel. The difference in the manufacturing process from Example 1 is that the injection speed is 50 g / s.

[0043] Comparative Example 1 This comparative example provides high-carbon high-alloy steel. The difference in the manufacturing process from Example 1 is that the high-carbon high-alloy molten steel is heated to 1450 °C, and the ingot is obtained by casting according to the conventional die casting method and then cooled to room temperature.

[0044] Comparative Example 2 This comparative example provides a high-carbon high-alloy steel. The manufacturing process is different from that of Example 1 in that the high-carbon high-alloy molten steel is heated to 1450 °C, cast according to the conventional mold casting method to obtain an ingot, and then the heat treatment process is carried out in the same manner as in Example 1.

[0045] Comparative Example 3 This comparative example provides a high-carbon high-alloy steel. The manufacturing process is different from that of Example 1 in that the high-carbon high-alloy ingot is heated to 800 °C and held for 4 hours, and then naturally cooled in the furnace.

[0046] Comparative Example 4 This comparative example provides a high-carbon high-alloy steel. The manufacturing process is different from that of Example 1 in that heat treatment is not performed, and the molten steel obtained by smelting is injected. However, due to the high viscosity of the alloy melt, it cannot be smoothly injected from the nozzle, and the nozzle is easily clogged.

[0047] Figure 1 is the ingot microstructure diagram of Example 1, Figure 2 is the ingot microstructure diagram of Example 2, and Figure 3 is the ingot microstructure morphology of Comparative Example 1. Note: Figures 1 to 3 are all the original microstructures without heat treatment.

[0048] As a result of the analysis, it was found that there are two types of carbides in the microstructure. The gray carbide is MC-type carbide, and the white carbide is M 2 C carbide. Since the ingots in Figures 1 and 2 are formed according to a specific melt impact method, among them, the gray carbide has a uniformly dispersed particle shape, is very fine and uniform, and the white carbide is in a banded or rod shape. The carbide in the ingot of Figure 2 is finer than that in the ingot of Figure 1 due to a stronger impact effect. The gray carbide in the ingot of Figure 3 has various shapes from petal-like to thick network-like, is severely aggregated, divides the matrix, and the white carbide is in a banded or rod shape and is also larger in size than in Figures 1 and 2.

[0049] Also, as shown in the following table, perform a statistical analysis of the carbide sizes of two different ingot microstructures using Image-Pro Plus. JPEG2025517117000002.jpg35163

[0050] Figure 4 is a micrograph (optical micrograph) of the microstructure of the high-carbon high-alloy steel of Example 1 (the ingot was subjected to specific heat treatment). As can be seen from Figure 4, the final microstructure mainly consists of MC carbide and M 6 C carbide.

[0051] Comparing Figure 1 and Figure 4, the reasons for the change in the microstructure are as follows. The MC-type carbide in the ingot is stable and does not change during subsequent heat treatment. M 2 C carbide is a metastable phase and decomposes into MC and M 6 C during subsequent heat treatment. After heat-treating the ingot, the size of M 2 C carbide cannot be counted, and it mainly consists of MC-type carbide and M 6 C carbide.

[0052] The microstructure of the high-carbon high-alloy steel of Comparative Example 3 (the ingot was not particularly heat-treated) is composed of pearlite and granular carbide. Compared with the alloy steel of Example 1, this alloy steel is considered to be an intermediate state (spheroidizing annealing) for reducing the alloy hardness and making organizational preparations for subsequent quenching-tempering.

[0053] In summary, according to the carbide refinement method of the high-carbon high-alloy steel according to the embodiments of the present application, a high-carbon high-alloy steel with a dense structure and fine carbides can be obtained.

[0054] The above is only an example of the embodiments of the present application and is not intended to limit the scope of the present application. Those skilled in the art will come up with various modifications and deformations to the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle scope of the present application shall be included in the protection scope of the present application.

Claims

1. A method for refining carbides of high-carbon high-alloy steel, comprising: preparing raw materials according to the chemical element composition of high-carbon high-alloy steel, and smelting to obtain high-carbon high-alloy molten steel; superheating the high-carbon high-alloy molten steel to Tm+(50-100)°C to obtain high-carbon high-alloy molten metal, and depositing the high-carbon high-alloy molten metal into a preset water-cooled copper mold at a speed of 30-160 g / s through an inert gas, and solidifying and forming to obtain a high-carbon high-alloy ingot; performing a heat treatment process on the high-carbon high-alloy ingot. A method for refining carbides of high-carbon high-alloy steel, characterized by comprising the above steps.

2. The chemical element composition of the high-carbon high-alloy steel is, by weight percentage, C: 1.5-2.5%, W: 2.5-10%, Mo: 3-7%, Cr: 4-6%, V: 2-10%, Si: 0.3-0.6%, Mn: 0.3-0.8%, and the balance is Fe. The method for refining carbides of high-carbon high-alloy steel according to Claim 1, characterized by this.

3. The heat treatment process includes high-temperature solution treatment, low-temperature interrupted quenching, and tempering treatment performed sequentially. The high-temperature solution treatment is maintained at 900-1050°C for 15-60 minutes, the low-temperature interrupted quenching is maintained at 700-860°C for 1-2 hours, and the tempering treatment is maintained at 520-580°C for 3-4 hours. The method for refining carbides of high-carbon high-alloy steel according to Claim 1, characterized by this.

4. After the high-temperature solution treatment is completed, oil quenching is performed to room temperature, and then low-temperature interrupted quenching is performed, and / or after the low-temperature interrupted quenching is completed, water quenching is performed to the martensite transformation point, oil quenching is performed to room temperature, and tempering treatment is performed. The method for refining carbides of high-carbon high-alloy steel according to Claim 3, characterized by this.

5. The superheat treatment method includes evacuating the chamber containing high-carbon high-alloy molten steel to 100-400 Pa, filling with an inert gas for protection, and then heating the high-carbon high-alloy molten steel to obtain high-carbon high-alloy molten metal. The method for refining carbides of high-carbon high-alloy steel according to Claim 1, characterized by this.

6. The superheat treatment is performed by a coil heating method. The method for refining carbides of high-carbon high-alloy steel according to Claim 1 or 5, characterized by this.

7. The method of molten metal deposition includes filling an inert gas for protection, heating a high-carbon high-alloy molten steel to obtain a high-carbon high-alloy molten metal, and then continuously filling an inert gas to promote the injection of the high-carbon high-alloy molten metal into an external chamber. The method for refining carbides of high-carbon high-alloy steel according to claim 5, characterized in that it comprises the above steps.

8. The high-carbon high-alloy molten metal is deposited under the action of a pressure difference, and the pressure difference is 0.05 to 0.25 MPa. The method for refining carbides of high-carbon high-alloy steel according to claim 1 or 7, characterized in that it has the above feature.

9. The distance between the nozzle outlet of the chamber where the high-carbon high-alloy molten metal is located and the water-cooled copper mold is 11 to 20 cm, and / or the water outlet temperature of the water-cooled copper mold is 30 to 45 °C. The method for refining carbides of high-carbon high-alloy steel according to claim 1 or 7, characterized in that it has the above features.

10. The outlet shape of the nozzle is a round hole type or a slit type, and all nozzles are arranged in an array. The method for refining carbides of high-carbon high-alloy steel according to claim 9, characterized in that it has the above feature.

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