A plunger pump used in the metallurgical engineering industry

Abstract

The present invention discloses a plunger pump for use in the metallurgical engineering industry, comprising a plunger pump cylinder, the plunger pump cylinder comprising a base and a composite wear-resistant layer formed on the surface of the base; the composite wear-resistant layer comprising a high-wear-resistant ceramic material layer and a ceramic-based composite material layer serving as an interface transition layer; the ceramic-based composite material layer in the composite wear-resistant layer is prepared from epoxy resin, polysiloxane, reinforcing fiber, graphite powder, and a balance of ceramic matrix powder of the same material as the high-wear-resistant ceramic material layer as raw materials, while the high-wear-resistant ceramic material layer is formed by pressing ceramic powder into a blank after adding a sintering aid according to a required component ratio onto the surface of a primary dry-pressed blank, and then carbonizing and sintering after a secondary dry-pressing. The present invention can effectively improve the performance of plunger pumps in the metallurgical engineering industry in conveying media with uneven and high-hardness particles, improve their high-pressure delivery stability, and ensure the service life of the pump body.

Description

Technical Field

[0001] The present invention relates to the technical field of plunger pumps, in particular to a plunger pump used in the metallurgical engineering industry. Background Art

[0002] As the main equipment for high-pressure conveying liquid media, the plunger pump mainly includes components such as cylinder, crankshaft, tappet and plunger. The crankshaft is located in the power end housing of the cylinder, one end of the tappet penetrates into the power end housing and is connected to the crankshaft, and the other end of the tappet is located outside the power end housing and is connected to the plunger. The plunger relies on the reciprocating motion of the plunger in the hydraulic end housing of the cylinder to change the volume of the sealed working chamber to achieve the absorption and pumping of the pumping medium. It has the advantages of good self-priming ability, high efficiency, high pressure, large flow, etc., and can convey media containing many impurities. It is widely used in occasions with high pressure, large flow and flow adjustment.

[0003] In the metallurgical engineering industry, plunger pumps are often used to transport materials such as ore slurry. This type of conveying medium usually contains a large amount of broken rock particles and high-hardness particles such as mud and sand. At present, the cylinder structure of the plunger pump is usually made of high-strength materials such as steel through a series of processes such as casting and forging. When the cylinder of this type of plunger pump is pumping the above-mentioned conveying medium, the high-hardness particles in the conveying medium will frequently rub against the side wall of the plunger pump cylinder, causing serious wear of the cylinder. This long-term contact wear will affect the head of the high-pressure plunger pump, and it needs to be replaced and maintained at irregular intervals during use, resulting in material waste and increased production costs. In addition, the plunger pump cylinder formed of the above-mentioned materials generally has corrosion resistance defects, which makes the hydraulic end housing extremely prone to stress corrosion in an acidic environment, thereby greatly affecting the service life of the plunger pump and causing the safety and reliability of the plunger pump to decline.

[0004] Based on the above-mentioned usage defects, there are also some plunger pump cylinders on the market that are made of special materials. These can make the plunger pump cylinder have the advantages of structural strength, wear resistance, corrosion resistance, etc. However, they generally have the defects of complex preparation process and high cost, which are not suitable for application in industrial fields such as petroleum and metallurgy. At present, the most suitable method is still the combination structure of base and inner wall lining material. The inner wall lining material is mostly made of high-wear-resistant ceramic material or high-wear-resistant alloy. Among them, high-wear-resistant ceramic materials usually have the performance advantages of high hardness, high strength, high temperature resistance, oxidation resistance, and corrosion resistance. However, the high-wear-resistant ceramic lining of a single structure is easily affected by the external environment during use and produces problems such as cracks and deformation. At the same time, the interface bonding performance between high-wear-resistant ceramic and the base material of the plunger pump cylinder is poor, and the material has many internal voids, poor density, low hardness, and poor mechanical properties such as bending strength. These shortcomings limit the application prospects of the above-mentioned hydraulic plunger pump cylinder. Summary of the Invention

[0005] The technical problem solved by the present invention is to provide a plunger pump for the metallurgical engineering industry, which can be used to solve the defects in the above technical background.

[0006] The technical problem solved by the present invention is achieved by adopting the following technical solutions:

[0007] A plunger pump for use in the metallurgical engineering industry, comprising a plunger pump cylinder, wherein the plunger pump cylinder comprises a base and a composite wear-resistant layer formed on the surface of the base;

[0008] The composite wear-resistant layer includes a high-wear-resistant ceramic material layer formed on the outside and serving as the contact surface of the conveying medium, and an interface transition layer formed between the substrate and the high-wear-resistant ceramic material layer. The interface transition layer is a ceramic-based composite material layer, and the thickness ratio of the high-wear-resistant ceramic material layer to the interface transition layer is 2:1 to 3:1;

[0009] The composite wear-resistant layer is obtained by forming:

[0010] 15-30 wt% of epoxy resin, 3-8 wt% of polysiloxane, 7-12 wt% of reinforcing fiber, 8-10 wt% of graphite powder, and the remainder of ceramic matrix powder made of the same material as the high wear-resistant ceramic material layer are weighed as raw materials in proportion by mass; wherein the molecular weight of the polysiloxane is 12,000-18,000, and the reinforcing fiber is a carbon fiber modified by treating a silane coupling agent as a matrix, and a SiC layer is deposited on the surface of the carbon fiber by chemical vapor deposition to form a modified fiber;

[0011] During the preparation, 1 / 3 of the ceramic matrix powder by mass is modified with an aminosilane coupling agent, the modified ceramic matrix powder is then mixed with reinforcing fibers and added to a ball mill for primary ball milling for 7 to 15 hours, and then the remaining ceramic matrix powder, epoxy resin, polysiloxane, and graphite powder are added for secondary ball milling. After the ball milling for 6 to 8 hours, the milled slurry is vacuum treated and then placed into a mold for dry pressing to obtain a primary dry-pressed green body of the ceramic matrix composite material layer.

[0012] Then, the ceramic powder in the high wear-resistant ceramic material layer is added with a sintering aid according to a required component ratio, mixed, and then put into a mold for dry pressing. During dry pressing, the powder is formed on the surface of the primary dry-pressed green blank, and a secondary dry-pressed green blank with a composite wear-resistant layer is obtained after trimming.

[0013] The composite wear-resistant layer is obtained by carbonizing and sintering the secondary dry-pressed green blank.

[0014] As a further limitation, the base is a plunger pump cylinder base made of bronze, high-strength brass, or steel as an integral molding material, and has a molding margin for a composite wear-resistant layer.

[0015] As a further limitation, the substrate has undergone surface roughening treatment on the molding side surface corresponding to the composite wear-resistant layer.

[0016] As a further limitation, the surface of the plunger used in conjunction with the plunger pump cylinder body is added with tin-lead bronze to optimize the wear resistance of the structural surface by casting or inlaying.

[0017] As a further limitation, the dry pressing of the ceramic-based composite material layer is carried out at a temperature of 150-170°C and a pressing pressure of 120-150 MPa. The pressed blank is obtained after maintaining the pressure for 5-15 minutes during the dry pressing process. After the pressed blank is trimmed and formed, it is stored and aged at a temperature of 70-90°C for 7-15 hours.

[0018] As a further limitation, the ceramic powder used in the high wear-resistant ceramic material layer is a ceramic powder that reaches 2400-3000 kg / mm ​​in the Vickers hardness test. 2 One of alumina ceramics, silicon carbide ceramics, zirconia ceramics, and boron carbide ceramics.

[0019] As a further limitation, the sintering aid added to the high wear-resistant ceramic material layer is a mixture of carbon and boron, and its amount is 1 to 3% of the mass of the ceramic powder.

[0020] As a further limitation, the dry pressing of the secondary dry-pressed blank is carried out at a temperature of 160-200°C and a pressing pressure of 250-300 MPa. The pressed blank is obtained after maintaining the pressure for 5-15 minutes during the dry pressing process. After the blank is trimmed and formed, the pressed blank is stored and aged at a temperature of 70-90°C for 12-18 hours.

[0021] As a further limitation, the composite wear-resistant layer is directly bonded to the inner surface of the hydraulic end housing of the base through an adhesive layer, and a reinforced fiber fabric lining layer is formed between the adhesive layer and the base.

[0022] As a further limitation, the carbonization and sintering operations of the secondary dry-pressed green billet are carried out in a vacuum or inert gas environment, first heated to 900-1200°C at a heating rate of 2-3°C / min, and kept warm for 70-90 minutes for carbonization treatment; then heated to 1400-1500°C at a heating rate of 5-10°C / min for heat preservation and sintering, and the sintering time is 150-210 minutes; then cooled to room temperature with the furnace to obtain a composite wear-resistant layer that can be used as a lining structure of the substrate.

[0023] Beneficial effects: The plunger pump of the present invention for the metallurgical engineering industry can form a stable ceramic lining structure in the hydraulic end housing of a traditional metal plunger pump cylinder by post-forming. The ceramic lining structure can effectively improve the adhesion of the wear-resistant ceramic material to the metal structure as the substrate when used as the lining structure through the interface transition layer in the composite wear-resistant layer, and improve the interface performance between the two.

[0024] The interface transition layer is reinforced with modified fiber materials, which can effectively improve the structural stability of the high-wear-resistant ceramic material layer as the contact surface of the conveying medium, enhance its resistance to temperature changes and impact, and reduce or even avoid the problem of cracks and deformation of the high-wear-resistant ceramic material layer being easily affected by the external environment;

[0025] The structural combination of the composite wear-resistant layer enables the high-wear-resistant ceramic material layer to utilize the wear resistance, stability and corrosion resistance of the ceramic material to effectively improve the flow efficiency of the conveying medium in the pump cavity, thereby ensuring the pumping efficiency of the plunger pump and resisting the impact and wear of high-hardness particles in the fluid medium on the cavity wall, which can greatly improve the wear resistance of the hydraulic plunger pump cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a diagram of the interlayer structure pattern of a preferred embodiment of the present invention.

[0027] Among them: 1. substrate; 2. ceramic matrix composite material layer; 3. high wear-resistant ceramic material layer. DETAILED DESCRIPTION

[0028] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below with reference to specific illustrations.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0030] Secondly, the "one embodiment" or "embodiment" referred to herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The "in one embodiment" that appears in different places in this specification does not refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments. In addition, in the embodiments of the present invention, all directional indications (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement, etc. between the various components in a certain specific form (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0031] See also Figure 1 A preferred embodiment of a plunger pump for the metallurgical engineering industry, wherein the plunger pump is used to pump high-concentration ore slurry, wherein the ore slurry contains a relatively high proportion of broken rock particles and high-hardness particles such as mud and sand. The above-mentioned high-hardness particles will cause a large amount of friction on the inner side wall of the cylinder when flowing through the space inside the hydraulic end shell of the plunger pump cylinder, thereby causing serious wear of the plunger pump cylinder, resulting in reduced pumping efficiency or even failure of the plunger pump. Therefore, this embodiment adopts a technical solution to structurally strengthen the inner wall of the hydraulic end shell of the above-mentioned plunger pump cylinder.

[0032] It should be noted that, in this embodiment, the high wear-resistant ceramic material layer 3 as the contact surface of the conveying medium can be formed from a high wear-resistant ceramic material already available in the prior art, or can be formed from a high wear-resistant ceramic material having a hardness of 2400 to 3000 kg / mm ​​in a Vickers hardness test. 2 A single material selected from alumina ceramic, silicon carbide ceramic, zirconium oxide ceramic, or boron carbide ceramic. Its wear resistance against high-hardness particles in the conveying medium is consistent with the inherent properties of the corresponding high-wear-resistant ceramic. However, this embodiment utilizes a single material, silicon carbide ceramic, to address issues such as the stable adhesion of the high-wear-resistant ceramic layer 3 to the substrate 1, as well as the brittle nature of the high-wear-resistant ceramic layer 3, which is susceptible to cracking and deformation due to external environmental influences such as temperature.

[0033] The plunger pump of this embodiment includes a base 1 formed of a metal material at the hydraulic end housing of the pump body. The base 1 is integrally formed of a metal material serving as the pump cylinder body, and the material for forming it can be one of bronze, high-strength brass, and steel. The material used in this embodiment is 45# steel. The base 1 corresponding to the hydraulic end housing section on the plunger pump cylinder body has a molding margin for the composite wear-resistant layer on the molding side surface corresponding to the composite wear-resistant layer, and has undergone surface roughening treatment. The roughening treatment is performed by rough surface grinding, so that the surface has a certain degree of roughness, which not only increases the contact area, but also helps to improve the mechanical and chemical bonding strength of the base 1 and the ceramic-based composite material layer 2 through the adhesive.

[0034] The corresponding composite wear-resistant layer is bonded to the correspondingly sized excess surface of the substrate 1 and the gap is filled with adhesive to complete the bonding process. In another embodiment, to further ensure the bonding and adhesion between the composite wear-resistant layer and the substrate 1, a reinforcing fiber fabric lining layer may be formed between the adhesive layer and the substrate 1.

[0035] In this embodiment, the composite wear-resistant layer includes a ceramic-based composite material layer 2 adjacent to one side of the substrate 1 and a high-wear-resistant ceramic material layer 3 serving as a contact surface for the conveying medium.

[0036] The thickness and material of the high wear-resistant ceramic material layer 3 determine the wear resistance to the conveying medium, which directly affects the life of the plunger pump. If it is too thin, it cannot achieve the desired effect, and if it is too thick, it will affect the structural forming of the cylinder body and cause waste of layer thickness. The preferred solution adopted in this embodiment is 1 / 2 of the thickness of the thinnest part of the wall of the base 1.

[0037] The ceramic-based composite material layer 2 mainly affects the adhesion performance of the high-wear-resistant ceramic material layer 3. It can indirectly improve the adhesion performance of the high-wear-resistant ceramic material layer 3 on the substrate 1 by serving as an interface transition layer, and can improve the structural toughness of its own material, and buffer the impact force on the side wall when the medium fluid conveyed on the cavity side flows through, as well as the thermal stress impact caused by the temperature changes of the internal and external environments, thereby preventing problems such as cracks and deformation caused by the brittleness of the ceramic material, thereby ensuring the service life of the plunger pump cylinder; the thickness of the ceramic-based composite material layer 2 is 1 / 3 of the thickness of the high-wear-resistant ceramic material layer 3.

[0038] In this embodiment, the composite wear-resistant layer composed of the ceramic-based composite material layer 2 and the high-wear-resistant ceramic material layer 3 is obtained by the following method:

[0039] First, 20wt% of epoxy resin, 5wt% of polysiloxane, 10wt% of reinforcing fiber, 10wt% of graphite powder and 55wt% of silicon carbide ceramic powder are weighed according to the mass ratio, wherein the molecular weight range of the polysiloxane as the raw material is 14000-17000, and the reinforcing fiber as the raw material uses carbon fiber as the matrix, which is then modified using a silane coupling agent, and then the modified carbon fiber is used as the substrate, trichloromethylsilane, hydrogen and argon are used as gas sources, and a SiC layer is deposited on the surface of the substrate by chemical vapor deposition to obtain the obtained product.

[0040] During the preparation, the silicon carbide ceramic powder accounting for 1 / 3 of the mass ratio is modified with an aminosilane coupling agent, and then the modified silicon carbide ceramic powder is mixed with the reinforcing fiber and added to a ball mill for one ball milling, and the ball milling time is controlled to be 4.5 hours; in the above process, the silicon carbide ceramic powder is modified with an aminosilane coupling agent to make the surface of the silicon carbide nanoparticles have amino groups, and the silicon carbide nanoparticles are grafted to the surface of the carbon fiber by reacting the amino group with the hydroxyl and carboxyl groups on the surface of the oxidized carbon fiber. Due to the high-temperature cracking of the carbon fiber during the sintering process, an effective pulling structure can be formed in the system of the ceramic-based composite material layer 2, so as to achieve the purpose of structural reinforcement and toughening of the ceramic-based composite material layer 2.

[0041] Then, the remaining 2 / 3 of silicon carbide ceramic powder, epoxy resin and polysiloxane, graphite powder and an appropriate amount of pure water are added for secondary ball milling. After ball milling for 7 hours, a slurry material is obtained. The slurry after ball milling is put into a vacuum pressure tank, and after vacuum treatment, it is injected into a mold for a dry pressing molding. The dry pressing pressure of the equipment is set to 130MPa and the dry pressing temperature is set to 155℃ for dry pressing. During the dry pressing process, the pressed green billet is kept warm and pressured for 10 minutes. After the pressed green billet is trimmed and formed, it is stored and aged at a temperature of 80℃ for 12 hours to obtain a primary dry pressed green billet, which is the green body of the ceramic-based composite material layer.

[0042] Then, a high wear-resistant ceramic material layer is prepared using silicon carbide ceramic powder of the same type and batch. During the preparation, silicon carbide ceramic powder is weighed according to the amount, and the required silicon carbide ceramic powder is mixed with a mixture powder of carbon and boron with a mass ratio of 1:1, which accounts for 2% of the mass of the ceramic powder, as a sintering aid. The mixture is then put into a mold for dry pressing. During dry pressing, the mixture is formed on the surface of the primary dry-pressed blank and a secondary dry pressing molding is performed together. The dry pressing pressure of the equipment is set to 250-300 MPa and the dry pressing temperature is set to 180°C for secondary dry pressing. During the dry pressing process, the pressed blank is kept warm and pressured for 10 minutes. After the pressed blank is trimmed and formed, it is stored and aged at a temperature of 80°C for 16 hours to obtain a secondary dry-pressed blank. The secondary dry-pressed blank is the blank of the composite wear-resistant layer.

[0043] In the above process, the primary dry pressing process can improve the interfacial bonding between graphite powder and silicon carbide ceramic powder through the combined action of polysiloxane and external pressure, thereby improving the mechanical properties of the composite material; and the secondary dry pressing process can strengthen the composite performance of the solid solution and silicon carbide ceramic powder, thereby improving the wear resistance of the high wear-resistant ceramic material layer 1, ensuring the service life of the hydraulic plunger pump cylinder, and thus ensuring the service life of the plunger pump.

[0044] The above-mentioned secondary dry-pressed green billet is carbonized and sintered in sequence. During the treatment, the secondary dry-pressed green billet is placed in a vacuum furnace, heated to 1200°C at a set heating rate of 3°C / min in an inert gas environment, and kept warm for 70 minutes before carbonization treatment; then the temperature is increased to 1460°C at a heating rate of 8°C / min and kept warm for sintering for 180 hours; then it is cooled to room temperature with the furnace to obtain a composite wear-resistant layer that can be used as a lining structure of the substrate.

[0045] The composite wear-resistant layer is attached to the surface of the molding allowance position of the substrate 1 of corresponding size, and the gap is filled with adhesive to complete the bonding molding to obtain a finished plunger pump cylinder. The plunger pump cylinder is assembled to obtain a finished plunger pump.

[0046] Twenty comparison groups were set up, and continuous pumping operations were performed with the same slurry material, and then compared one by one. Compared with a plunger pump prepared by directly using silicon carbide ceramic powder to prepare a plunger pump cylinder with the same thickness as the composite wear-resistant layer as the lining structure, the finished plunger pump of this embodiment pumped the same slurry material with the same operating parameters, and its service life was improved by 46% to 64%.

[0047] Twenty comparison groups were set up, and continuous pumping operations were performed with the same slurry material, and then compared one by one. Compared with a plunger pump prepared by directly using silicon carbide ceramic powder to prepare a plunger pump cylinder with the same thickness as the high-wear-resistant ceramic material layer as the lining structure, the finished plunger pump of this embodiment pumped the same slurry material with the same operating parameters, and its service life was improved by 72% to 94%.

[0048] Twenty comparison groups were set up to perform continuous pumping operations with the same slurry material, and then compared one by one. The service life of the finished plunger pump of this embodiment was improved by 164-189% compared with the plunger pump of the all-steel cylinder structure without an inner lining structure.

[0049] Based on this, the plunger pump structure of this embodiment has technical advantages.

[0050] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the purpose of these embodiments is only to illustrate the present invention and is not intended to limit the scope of protection of the present invention. In addition, it should also be understood that after reading the technical content of the present invention, those skilled in the art may make various changes, modifications and / or variations to the present invention, and all of these equivalent forms also fall within the scope of protection defined by the claims appended hereto.

Claims

1. A plunger pump for metallurgical engineering industry, characterized in that: The plunger pump cylinder comprises a base and a composite wear-resistant layer formed on the surface of the base; The composite wear-resistant layer includes a high-wear-resistant ceramic material layer formed on the outside and serving as the contact surface of the conveying medium, and an interface transition layer formed between the substrate and the high-wear-resistant ceramic material layer. The interface transition layer is a ceramic-based composite material layer, and the thickness ratio of the high-wear-resistant ceramic material layer to the interface transition layer is 2:1 to 3:1; The composite wear-resistant layer is obtained by forming: 15-30 wt% of epoxy resin, 3-8 wt% of polysiloxane, 7-12 wt% of reinforcing fiber, 8-10 wt% of graphite powder, and the remainder of ceramic matrix powder made of the same material as the high wear-resistant ceramic material layer are weighed as raw materials in proportion by mass; wherein the molecular weight of the polysiloxane is 12,000-18,000, and the reinforcing fiber is based on carbon fiber modified by treating with a silane coupling agent, and a SiC layer is deposited on the surface of the carbon fiber by chemical vapor deposition to form a modified fiber; During the preparation, 1 / 3 of the ceramic matrix powder by mass is modified with an aminosilane coupling agent, the modified ceramic matrix powder is then mixed with reinforcing fibers and added to a ball mill for primary ball milling for 7 to 15 hours, and then the remaining ceramic matrix powder, epoxy resin, polysiloxane, and graphite powder are added for secondary ball milling. After the ball milling for 6 to 8 hours, the milled slurry is vacuum treated and then placed into a mold for dry pressing to obtain a primary dry-pressed green body of the ceramic matrix composite material layer. Then, the ceramic powder in the high wear-resistant ceramic material layer is added with a sintering aid according to a required component ratio, mixed, and then put into a mold for dry pressing. During dry pressing, the powder is formed on the surface of the primary dry-pressed green blank, and a secondary dry-pressed green blank with a composite wear-resistant layer is obtained after trimming. The composite wear-resistant layer is obtained by carbonizing and sintering the secondary dry-pressed green blank.

2. The plunger pump for metallurgical engineering industry according to claim 1, characterized in that: The base is a plunger pump cylinder base that is made of bronze, high-strength brass, or steel and is integrally formed, with a composite wear-resistant layer forming margin left.

3. The plunger pump for metallurgical engineering industry according to claim 1, characterized in that: The substrate has been subjected to surface roughening treatment on the molding side surface corresponding to the composite wear-resistant layer.

4. The plunger pump for metallurgical engineering industry according to claim 1, characterized in that: The surface of the plunger used in conjunction with the plunger pump cylinder body is added with tin-lead bronze by a casting or inlaying method.

5. The plunger pump for metallurgical engineering industry according to claim 1, characterized in that: The dry pressing of the ceramic matrix composite material layer is carried out at a temperature of 150-170°C and a pressing pressure of 120-150 MPa. After the dry pressing process, the pressure is maintained for 5-15 minutes to obtain a pressed green blank. After the pressed green blank is trimmed and formed, it is stored and aged at a temperature of 70-90°C for 7-15 hours.

6. The plunger pump for metallurgical engineering industry according to claim 1, characterized in that: The ceramic powder used in the high wear-resistant ceramic material layer is a ceramic powder that reaches 2400-3000 kg / mm ​​in the Vickers hardness test. 2 One of alumina ceramics, silicon carbide ceramics, zirconia ceramics, and boron carbide ceramics.

7. The plunger pump for metallurgical engineering industry according to claim 1, characterized in that: The sintering aid added to the high wear-resistant ceramic material layer is a mixture of carbon and boron, and its dosage is 1-3% of the mass of the ceramic powder.

8. The plunger pump for metallurgical engineering industry according to claim 1, characterized in that: The dry pressing of the secondary dry pressing green billet is carried out at a temperature of 160-200° C. and a pressing pressure of 250-300 MPa. The pressed green billet is obtained after maintaining the pressure for 5-15 minutes during the dry pressing process. The pressed green billet is then stored and aged at a temperature of 70-90° C. for 12-18 hours after the billet is trimmed and formed.

9. The plunger pump for metallurgical engineering industry according to claim 1, characterized in that: The composite wear-resistant layer is directly bonded to the inner surface of the hydraulic end shell of the base through an adhesive layer, and a reinforced fiber fabric lining layer is formed between the adhesive layer and the base.

10. The plunger pump for metallurgical engineering industry according to claim 1, characterized in that: The carbonization and sintering operations of the secondary dry-pressed green billet are carried out in a vacuum or inert gas environment. First, the temperature is heated to 900-1200°C at a heating rate of 2-3°C / min and kept warm for 70-90 minutes for carbonization treatment; then the temperature is raised to 1400-1500°C at a heating rate of 5-10°C / min and kept warm for sintering for 150-210 minutes; then the composite wear-resistant layer that can be used as a lining structure of the substrate is obtained by cooling it to room temperature with the furnace.

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