Powder metallurgy wear and corrosion resistant precipitation hardened high speed steel

Abstract

The application provides a powder metallurgy wear-resistant and corrosion-resistant precipitation hardening high-speed steel, which comprises the following components in percentage by mass: C: 0.1%-0.2%; Si: 0.3%-0.8%; Cr: 2.0%-15.0%; V: 0.05-2.0%; Co: 10.0%-30.0%; W: 0%-5.0%; Mo: 10%-28.0%; (Mo+W / 2): 10.0%-31.0%; and the balance is iron and impurities. The precipitated phase in the powder metallurgy wear-resistant and corrosion-resistant precipitation hardening high-speed steel comprises a large amount of intermetallic compound (IMC) μ phase and a small amount of MC carbide, wherein the μ phase is (Fe, Co)7(Mo+W / 2)6 type, and the MC carbide is V(C, N) type. The μ phase and the carbide of the precipitation hardening high-speed steel are small in size and uniformly distributed, have excellent comprehensive performance, especially wear resistance and corrosion resistance, and can meet the requirements of different working conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to a precipitation hardening high speed steel, in particular to a powder metallurgy wear and corrosion resistant precipitation hardening high speed steel. BACKGROUND

[0002] In the field of aerospace and marine chemical industry, tools or parts not only need to bear working stress load and impact, but also need to withstand the corrosion of moisture, acid or other corrosive media. In order to be suitable for these working conditions and have long service life, the material must have good strength and toughness matching and high corrosion resistance.

[0003] Precipitation hardening steel is a carbon-free ferritic martensitic precipitation hardening tool alloy. Due to the low content of C in the composition, no carbide is precipitated, and the structure is mainly ferritic matrix and Fe-Co-Mo-W intermetallic compound (i.e. IMC). The hardening effect is due to the precipitation of IMC particles during aging process. This kind of precipitation hardening high speed steel has good grindability and resistance to temper softening, and good dimensional stability.

[0004] Due to the limitation of the slow cooling and solidification characteristics of the steel liquid in the process of traditional casting and forging process, the alloy composition is easy to segregate during solidification. This undesirable structure cannot be effectively solved by hot working, which will adversely affect the performance of the alloy, resulting in low level of strength, toughness, grindability and other properties of high speed steel, which is difficult to meet the requirements of high-end machining and manufacturing on material performance and service life. The corrosion resistance of existing precipitation hardening steel is also difficult to meet the use in high-end field. SUMMARY

[0005] Therefore, the present application provides a powder metallurgy wear and corrosion resistant precipitation hardening high speed steel with good structure and excellent performance.

[0006] To achieve the above purpose, the technical scheme of the present application is as follows:

[0007] A powder metallurgy wear and corrosion resistant precipitation hardening high speed steel, characterized in that the steel comprises the following chemical components in mass percentage:

[0008] C: 0.1%-0.2%;

[0009] Si: 0.3%-0.8%;

[0010] Cr: 2.0%-15.0%;

[0011] V: 0.05-2.0%;

[0012] Co: 10.0%-30.0%;

[0013] W: 0% - 5.0%;

[0014] Mo: 10% - 28.0%;

[0015] (Mo + W / 2): 10.0% - 31.0%;

[0016] balance being iron and impurities;

[0017] and, the precipitated phase in the powder metallurgy wear-resistant and corrosion-resistant precipitation hardening high-speed steel includes a large amount of intermetallic compound (IMC) μ phase and a small amount of MC carbide, wherein the μ phase is of the type (Fe, Co)7(Mo + W / 2)6, and the MC carbide is of the type V(C, N).

[0018] The present application improves the wear resistance and corrosion resistance of the steel through rational design of the alloy composition and ratio.

[0019] Specifically, the content of C (carbon) in the precipitation hardening high-speed steel in the present application needs to be controlled in the range of 0.1% - 0.2%, preferably C: 0.1% - 0.18%, to reduce the precipitation of carbides, mainly to achieve strengthening in the form of μ phase, and a small amount of C in the steel is used to form carbides, further improving the wear resistance of the precipitation hardening steel.

[0020] The role of Co (cobalt) is to dissolve in the matrix, making the alloy a martensitic steel, thereby increasing the hardness and strength of the alloy by one level compared to ferritic alloys. Increasing the content of Co will appropriately reduce the toughness of the steel. In the present application, the content of Co element is in the range of 10.0% - 30.0%, preferably 14.0% - 30.0%.

[0021] W (tungsten) has a high melting point, which increases the strength and tempering stability of the steel, increases the creep resistance at high temperature, and increases the resistance of the steel to temper softening, so that the surface layer of the steel has less temperature rise and less hardness drop during processing and use. In the present application, the content of W element is in the range of 0% - 5.0%, preferably 0% - 3.0%.

[0022] Mo (molybdenum) has the same effect as W and can completely replace W, and the price is lower than W. On the other hand, the higher the Mo content, the higher the initial precipitation temperature of μ phase, and the larger the particle size of μ phase. In the present application, the content of Mo element is in the range of 10% - 28.0%, preferably 10% - 27.0%.

[0023] The role of Cr (chromium) added to the steel is that it can coarsen the particles, so that the red hardness is reduced and the machinability is improved. On the other hand, part of Cr dissolves in the matrix, which can improve the corrosion resistance and hardenability of the steel. In the present application, the content of Cr element is in the range of 2.0% - 15.0%, preferably 2.0% - 12.0%.

[0024] V (alum) as a strong carbide forming element, the main role is to form MC type carbide with steel, improve the wear resistance of steel, so that more Cr is dissolved in the matrix to further improve the wear resistance, in order to ensure that the strengthening mechanism of the steel is still mainly μ phase, and ensure the grindability of the steel, the content of V element in the application is 0.05%-2.0%, preferably 0.05%-1.7%.

[0025] Si (silicon) is not a carbide forming element, but is used as a deoxidizer and matrix strengthening element, which can improve the strength and hardness of the steel, but too much Si will reduce the plasticity and toughness of the matrix, the Si content in the application is controlled below 1.0%, and preferably ≤0.8%.

[0026] As a preferred limitation of the above-mentioned manner, the powder metallurgy wear-resistant and corrosion-resistant precipitation hardening high-speed steel comprises the following chemical components by mass percentage:

[0027] C: 0.1%-0.18%;

[0028] Si: 0.3%-0.6%;

[0029] Cr: 2.0%-12.0%;

[0030] V: 0.05-1.7%;

[0031] Co: 14.0%-30.0%;

[0032] W: 0%-3.0%;

[0033] Mo: 10%-27.0%;

[0034] (Mo+W / 2): 10.0%-28.5%;

[0035] The balance is iron and impurities.

[0036] In order to achieve better comprehensive performance, each chemical component in the powder metallurgy wear-resistant and corrosion-resistant precipitation hardening high-speed steel of the application should be controlled within the required range.

[0037] Further, at least 80% by volume fraction of the μ phase to the particle size ≤1.5 μm, the maximum particle size of the μ phase is not more than 6.0 μm.

[0038] Further, the volume fraction of the μ phase in the powder metallurgy wear-resistant and corrosion-resistant precipitation hardening high-speed steel is 15-28%.

[0039] Further, at least 80% by volume fraction of the MC carbide has a particle size ≤1.5 μm, and the maximum particle size of the MC carbide is not more than 2.5 μm.

[0040] Further, the volume fraction of the MC carbide in the powder metallurgy wear-resistant and corrosion-resistant precipitation hardening high-speed steel is 1.0%-3.0%.

[0041] In the application, the powder metallurgy process is used to prepare the precipitation hardening steel, so that the element segregation problem can be solved to obtain a uniform structure, and the main steps of the powder metallurgy process for preparing the precipitation hardening high-speed steel include: atomization and powder preparation, hot isostatic pressing, the molten steel is rapidly cooled into powder, the alloy elements in the molten steel cannot segregate and completely solidify, and the powder is solidified into a material with fine and uniform structure, compared with the traditional casting or electroslag process for producing the precipitation hardening high-speed steel, the performance is greatly improved.

[0042] The application also provides a preparation method of the powder metallurgy wear-resistant and corrosion-resistant precipitation hardening high-speed steel.

[0043] s1. The molten steel of the precipitation hardening steel is prepared according to the above chemical composition requirements and is transferred to a ladle;

[0044] s1.1. The overheat degree of the molten steel is maintained by heating the protective slag covering the upper surface of the molten steel in the ladle, and the molten steel is stirred by introducing inert gas into the bottom of the ladle;

[0045] s1.2. The molten steel is flowed into the preheated tundish through the flow guide pipe at the bottom of the ladle at a stable flow rate, and the protective slag is applied to the upper surface of the molten steel when the molten steel enters the tundish and covers the lower end surface of the flow guide pipe;

[0046] s1.3. The tundish is continuously compensated and heated to maintain the overheat degree of the molten steel;

[0047] s1.4. After the molten steel enters the atomization chamber from the tundish, the inert gas is used for atomization and powder preparation, the obtained metal powder is settled at the bottom of the atomization chamber, and then enters the powder storage tank body with a protective atmosphere, and the metal powder is screened through the protective screening device and then enters the powder storage tank body for storage;

[0048] s1.5. Under the protection of inert gas, the metal powder in the powder storage tank body is transferred to the hot isostatic pressing jacket, the metal powder is vibrated and packed tightly, then the hot isostatic pressing jacket is vacuum degassed, the end part is sealed and welded, and then the hot isostatic pressing treatment is carried out to completely densify and consolidate the metal powder, and the powder metallurgy process is completed.

[0049] The powder metallurgy process includes non-vacuum melting atomization and powder preparation and hot isostatic pressing, and the whole process is protected to control the oxygen content and the morphology of precipitated phases and optimize the performance of the precipitation hardening steel.

[0050] The protective slag of the ladle has the functions of air insulation and electric heating. The inert gas is introduced into the ladle through the air hole at the bottom of the ladle, so that the molten steel at different positions in the ladle is balanced in temperature, and the removal of harmful inclusions is accelerated. The flow guide pipe at the bottom of the ladle plays a role in guiding the flow of molten steel, reducing the turbulence in the flow process of molten steel, avoiding slag entrainment and preventing inclusions from entering the next process. On the other hand, the flow guide pipe prevents the molten steel from being exposed to air, preventing the oxygen content of the molten steel from rising. Before the molten steel enters the tundish, the tundish needs to be preheated to prevent local condensation or the second phase from precipitating when the molten steel enters the tundish.

[0051] The powder storage tank has the functions of atmosphere protection and forced cooling, the powder protection screening device plays a protective role in the powder screening process and prevents the powder from floating, the powder storage tank body is sealingly connected with the hot isostatic pressing sleeve, and the hot isostatic pressing sleeve introduces inert gas to discharge air before powder is loaded, so that the oxygen content in the powder is prevented from rising.

[0052] The precipitation hardening high-speed steel prepared by the powder metallurgy process has reasonable component design, various effective protection means are adopted in the preparation process to prevent the molten steel and the powder from being polluted, which provides guarantee for obtaining high-performance precipitation hardening steel, and due to the specific chemical composition and the rapid condensation process of powder metallurgy, the intermetallic compound μ phase of the type (Fe, Co) 7 (Mo + W / 2) 6 is more fine and uniform, the hardness after heat treatment is above 65HRC, excellent hardness, tempering softening resistance and toughness are combined, and various application requirements can be met. BRIEF DESCRIPTION OF DRAWINGS

[0053] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this application. The embodiments of the present application illustrated in the drawings are presented by way of example or for purpose of explanation only. In the drawings:

[0054] Figure 1 The microstructure diagram of the precipitation hardening high-speed steel prepared in example 1 of the present application;

[0055] Figure 2 The microstructure diagram of the precipitation hardening high-speed steel prepared in example 2 of the present application;

[0056] Figure 3 The microstructure diagram of the precipitation hardening high-speed steel prepared in example 4 of the present application;

[0057] Figure 4 The microstructure diagram of the precipitation hardening high-speed steel prepared in example 5 of the present application;

[0058] Figure 5 The microstructure diagram of the precipitation hardening high-speed steel prepared in example 6 of the present application;

[0059] Figure 6Microstructure diagram of the powder metallurgy process corrosion-resistant high-speed steel prepared in the present application example 7;

[0060] Figure 7 Microstructure diagram of the powder metallurgy process corrosion-resistant high-speed steel prepared in the present application example 7;

[0061] Figure 8 Microstructure diagram of the powder metallurgy process corrosion-resistant high-speed steel prepared in the present application example 7; DETAILED DESCRIPTION

[0062] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0063] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0064] The present application relates to a group of powder metallurgy wear-resistant and corrosion-resistant precipitation hardening high-speed steel, which comprises the following chemical components in percentage by mass: C: 0.1%-0.2%; Si: 0.3%-0.8%; Cr: 2.0%-15.0%; V: 0.05-2.0%; Co: 10.0%-30.0%; W: 0%-5.0%; Mo: 10%-28.0%; (Mo+W / 2): 10.0%-31.0%; the balance is iron and impurities.

[0065] As preferred, the precipitation hardening high-speed steel of the present application comprises the following chemical components in percentage by mass: C: 0.1%-0.18%; Si: 0.3%-0.6%; Cr: 2.0%-12.0%; V: 0.05-1.7%; Co: 14.0%-30.0%; W: 0%-3.0%; Mo: 10%-27.0%; (Mo+W / 2): 10.0%-28.5%; the balance is iron and impurities.

[0066] The precipitation hardening high-speed steel composed of the above components can obtain ideal organization and excellent performance to meet the needs.

[0067] Secondly, the present application also relates to a method for preparing the above precipitation hardening high-speed steel, which is prepared by using traditional ingot or electroslag process. Since the solidification speed is slow, segregation is easy to occur, which leads to performance decline. Therefore, in order to ensure that the prepared precipitation hardening high-speed steel ingot has uniform composition and organization, fine precipitates and high purity, the powder metallurgy process is used to prepare the steel ingot, and then the required rod product is obtained through forging.

[0068] Specifically, the preparation method of the present application comprises the following steps:

[0069] s1. The molten steel of the precipitation hardening steel of the present application is loaded into a melting ladle, and the molten steel loading weight is 1.5-8 tons;

[0070] s1.1. Adopt graphite electrode to electric heating the protective slag covered on the upper surface of the liquid steel in ladle, and introduce argon or nitrogen gas into the bottom of the ladle to stir the liquid steel, and open the flow guide pipe of the liquid steel when the superheat of the liquid steel reaches 100-200℃;

[0071] s1.2. Flow the liquid steel into the tundish preheated to 800-1200℃ through the flow guide pipe at the bottom of the ladle at a flow rate of 10-50 Kg / min, and apply the protective slag when the liquid steel enters the tundish and covers the lower end surface of the flow guide pipe;

[0072] s1.3. Continuously compensate the heating of the tundish during the atomization and powdering process, and maintain the superheat of the liquid steel at 100-200℃;

[0073] s1.4. The liquid steel enters the atomization chamber through the bottom of the tundish, and open the atomization gas injection valve, and use nitrogen gas as the gas medium for atomization and powdering, the purity of the nitrogen gas is ≥99.999%, the oxygen content is ≤2ppm, and the outlet pressure of the gas nozzle is 1.0-5.0MPa; the liquid steel is broken into droplets under the action of nitrogen gas injection, and is rapidly cooled into metal powder, flies to the bottom of the atomization chamber, and then enters the powder storage tank body with a protective atmosphere; after the atomization and powdering is completed, the metal powder in the powder storage tank body is cooled to room temperature, and the metal powder is screened through the protective screening device; the cavity of the protective screening device is filled with positive pressure inert protective gas, and the inside of the powder storage tank is a positive pressure inert gas protective atmosphere;

[0074] s1.5. Fill the metal powder in the powder storage tank body into the hot isostatic pressing jacket, first introduce inert gas into the hot isostatic pressing jacket to discharge air, then tightly connect the hot isostatic pressing jacket and the powder storage tank body, and perform vibration operation during the filling process to increase the filling density of the metal powder; after completion, perform vacuum degassing treatment on the hot isostatic pressing jacket, heat and keep the hot isostatic pressing jacket at 200-600℃ during the vacuum process, continue to heat and keep for more than 2h after degassing to 0.01Pa, then perform sealing welding treatment on the end part of the jacket, and finally perform hot isostatic pressing treatment on the jacket, the hot isostatic pressing temperature is 1100-1180℃, and the pressure is ≥100MPa, and the holding time is ≥1h, so that the metal powder is completely densified and solidified, and then the furnace is cooled down, and the powder metallurgy process is completed.

[0075] s2. Open the blank by forging

[0076] The precipitated hardening high speed steel according to the application is further forged and deformed as needed to obtain a rod or a forged piece with a certain shape and size, and different properties are obtained by using different heat treatment systems, including annealing, solid solution and aging. The annealing treatment involves heating the rod or forged piece to 870-890℃, the holding time is ≥2h, then cooling to below 530℃ at a speed of ≤15℃ / h, and then furnace cooling or static air cooling to below 50℃; the solid solution treatment involves preheating the annealed rod or forged piece at a temperature of 810-850℃, then placing it in a temperature of 1170-1200℃ for 15-40 minutes after the temperature is uniform, and then oil cooling; then aging at a temperature range of 580-650℃, holding time of 3-4 hours, and then air cooling to 50℃.

[0077] The powder metallurgy wear-resistant and corrosion-resistant precipitated hardening high speed steel and its preparation according to the application will be further described below with specific preparation examples and comparative examples, and corresponding performance tests.

[0078] The second phase particle size and volume fraction, heat treatment hardness, wear resistance and corrosion resistance of the powder metallurgy wear-resistant and corrosion-resistant precipitated hardening high speed steel according to the application are verified, wherein the μ phase and carbide particle size and volume fraction are analyzed based on the microstructure images obtained by scanning electron microscopy, and the heat treatment hardness, wear resistance and corrosion resistance are tested according to GB / T 230.1, GB / T 12444, JB / T 7901 and GB / T 17899 respectively.

[0079] Eight kinds of precipitated hardening high speed steels with different component compositions are obtained by the above preparation method, and are compared with high Cr spray forming tool steel (alloy A) and cast forging tool steel (alloy B), and the results are as follows:

[0080] Table 1: Alloy composition

[0081] Alloy C Si Mn Cr Co V W Mo Mo + W / 2 Fe Example 1 0.12 0.41 - 4.98 15.61 0.32 0.01 25.45 25.45 Balance Example 2 0.16 0.39 - 4.05 14.74 0.20 0.01 22.24 22.24 Balance Example 3 0.12 0.41 - 4.98 15.61 0.32 2.0 20.0 21.0 Balance Example 4 0.10 0.30 - 2.0 10.0 0.05 0.0 10.0 10.0 Balance Example 5 0.20 0.80 - 15.0 30.0 2.0 5.0 28.0 31.5 Balance Example 6 0.10 0.30 - 2.0 14.0 0.05 0.0 10.0 10.0 Balance Example 7 0.18 0.60 - 12.0 30.0 1.7 3.0 27.0 28.5 Balance Example 8 0.19 0.70 - 13.0 13.0 1.8 4.0 27.6 29.6 Balance Comparative Example A 1.36 0.70 0.43 14.67 0.03 2.42 0.07 1.85 1.88 Balance

[0082] “-” in the table means that the element is not contained or the content of the element is very small and is not analyzed.

[0083] (I) Microstructure analysis

[0084] Based on the microstructure images obtained by scanning electron microscopy, Figures 1 to 6 are the microstructure diagrams of the prepared precipitated hardening steel forgings example 1, example 2, example 4, example 5, example 6, example 7, Figure 7 is the microstructure diagram of alloy A, Figure 8 is the microstructure diagram of alloy B.

[0085] It is obvious that Figures 1 to 6The hardened phase dispersed in the matrix in the middle gray white can significantly improve the wear resistance, toughness and service life of the material. Figure 7 and Figure 8 Two kinds of precipitated phases are contained in the middle, one is bright white and large in size, and the other is gray white and small in size.

[0086] The precipitated phase content and particle size of examples 1 to 8 and alloys A and B after heat treatment are as shown in table 2:

[0087] Table 2: content and particle size of precipitated phase

[0088]

[0089] The solid solution system of examples 1 to 8 is 1190℃x30 minutes, the aging system is temperature 600℃, time 3 hours; the quenching system of comparative example A is temperature 1180℃, time 15 minutes, the tempering system is temperature 550℃, time 2 hours, times 2; the quenching system of comparative example B is temperature 1185℃, time 15 minutes, the tempering system is temperature 550℃, time 1 hour, times 3.

[0090] The precipitated phase analysis of high speed steel prepared in examples 1 to 8 in the application is carried out: the precipitated phase in examples 1 to 8 is mainly IMC and MC carbide, wherein IMC is mainly μ phase, type is (Fe, Co)7(Mo+W / 2)6, MC carbide is V(C, N) type carbide; the precipitated phase in alloy A and alloy B is mainly detected, and the strengthening phase is mainly Cr-rich M6C type carbide, in addition, there is MC type carbide.

[0091] The volume fraction of μ phase of the precipitated hardening high speed steel in the application reaches 15%-28%, the particle size is small, most of the μ phase particle size is less than 1.5μm, and the maximum size is not more than 6.0μm; at least 80Vol% of MC carbide size is ≤1.5μm, and the maximum size is not more than 2.5μm. These precipitated phase sizes are small, the dispersion is large, and the μ phase also has excellent high temperature aggregation resistance, so that the material obtains better wear resistance, toughness and service life.

[0092] The MC type carbide size of alloy A prepared by powder metallurgy process and alloy B prepared by traditional electroslag process is close to that of examples, but there are also a large number of M6C type carbides with size range of 3-12μm in the organization, and the coarse carbide has the adverse effect of cutting the matrix.

[0093] (II) hardness and wear resistance analysis after heat treatment

[0094] In order to verify the influence of the heat treatment system on the properties of the prepared precipitation hardening high speed steel, the prepared rods are heat treated by setting different solid solution temperatures and aging temperatures.

[0095] The prepared high speed steels and alloys A and B in Examples 1 to 8 are heat treated, and the obtained hardness and wear resistance are compared, as shown in Table 3.

[0096] Table 3: Comparison of mechanical properties

[0097]

[0098] As can be seen from Table 3, after suitable heat treatment, the hardness of the precipitation hardening high speed steel of the present application reaches more than 64HRC, which can meet the requirements of the application field, and the comparison results of the wear resistance show that the precipitation hardening high speed steel of the present application has good wear resistance.

[0099] (Three) Corrosion resistance analysis

[0100] Examples 1 to 8 and alloys A and B are immersed in a 5% HNO3+1% HCl solution at room temperature, and then the corrosion rate is measured. Then the polarization curve is measured in a 1% NaCl solution, and finally the self-corrosion potential is obtained. The comparison results of the corrosion resistance are shown in Table 4.

[0101] Table 4: Comparison of corrosion resistance

[0102]

[0103]

[0104] As can be seen from the comparison data in Table 4, the precipitation hardening steel of the present application shows more excellent corrosion resistance. Because the C content in the precipitation hardening steel of the present application is very small, it basically does not precipitate with Cr in the form of carbide, and most of the Cr elements in the steel are solid-solved in the matrix, which can obtain higher corrosion resistance. According to the requirements of corrosion resistance in different application fields, suitable heat treatment system should be selected. Within a relatively wide heat treatment temperature range, the precipitation hardening high speed steel of the present application can have good strength and toughness and wear and corrosion resistance, so as to meet the application in the working condition with wear and corrosion.

[0105] In addition, due to the limitation of the particle number statistical image analysis software, the size of the individual μ phase and MC carbide in the microstructure of the prepared precipitation hardening steel of the present application may exceed the maximum size under the above implementation conditions, but due to the extremely small number, it has no substantial influence on the toughness and other mechanical properties of the precipitation hardening steel, and thus can be ignored. Many smaller μ phase particles cannot be identified by the analysis software, and the statistical results of the volume fraction and particle size are only for comparison.

[0106] Due to the specific alloy composition design and the powder metallurgy process, the material can obtain better strength and toughness ratio and wear and corrosion resistance, and can meet different application requirements, and can be used for manufacturing (1) cutters for cutting difficult-to-cut materials at high speed; (2) high-precision gauges; (3) wear-resistant and corrosion-resistant parts and the like.

[0107] In summary, the powder metallurgy wear-resistant and corrosion-resistant precipitation hardening high-speed steel has excellent comprehensive performance, especially good wear and corrosion resistance. Due to the characteristics of the alloy composition, the strengthening mechanism is different from that of the traditional high-speed steel, so that the anti-tempering softening capacity is greatly superior to that of the traditional high-speed steel and other tool steels, and at the same time, the wear and corrosion resistance is high.

[0108] The above only describes the preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A powder metallurgy wear-resistant and corrosion-resistant precipitation-hardening high-speed steel, characterized in that, Its chemical components, by mass percentage, include: C：0.1％-0.2％； Si: 0.3%-0.8%; Cr：2.0％-15.0％； V：0.05-2.0％； Co: 10.0%-30.0%; W：0％-5.0％； Mo: 10%-28.0%; (Mo+W / 2): 10.0%-31.0%; The balance consists of iron and impurities; Furthermore, the precipitated phases in the powder metallurgy wear-resistant and corrosion-resistant precipitation-hardening high-speed steel include intermetallic compounds and MC carbides. The intermetallic compounds are μ phases, and the type of μ phase is (Fe,Co)7(Mo+W / 2)6. The type of MC carbides is V(C,N) type.

2. The powder metallurgy wear-resistant and corrosion-resistant precipitation-hardening high-speed steel according to claim 1, characterized in that, Its chemical components, by mass percentage, include: C：0.1％-0.18％； Si: 0.3%-0.6%; Cr：2.0％-12.0％； V：0.05-1.7％； Co: 14.0%-30.0%; W：0％-3.0％； Mo: 10%-27.0%; (Mo+W / 2): 10.0%-28.5%; The balance consists of iron and impurities.

3. The powder metallurgy wear-resistant and corrosion-resistant precipitation-hardening high-speed steel according to claim 1 or 2, characterized in that: The μ phase, comprising at least 80% by volume, has a particle size ≤1.5 μm, and the maximum particle size of the μ phase does not exceed 6.0 μm.

4. The powder metallurgy wear-resistant and corrosion-resistant precipitation-hardening high-speed steel according to claim 1 or 2, characterized in that: The volume fraction of the μ phase in the powder metallurgy wear-resistant and corrosion-resistant precipitation-hardening high-speed steel is 15-28%.

5. The powder metallurgy wear-resistant and corrosion-resistant precipitation-hardening high-speed steel according to claim 1 or 2, characterized in that: The particle size of the MC carbide is ≤1.5 μm for at least 80% by volume, and the maximum particle size of the MC carbide is not more than 2.5 μm.

6. The powder metallurgy wear-resistant and corrosion-resistant precipitation-hardening high-speed steel according to claim 1 or 2, characterized in that: The volume fraction of MC carbides in the powder metallurgy wear-resistant and corrosion-resistant precipitation-hardening high-speed steel is 1.0%-3.0%.

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