Methods and products for powder-free hot isostatic pressing rapid prototyping of maintenance-free wear-resistant roller sleeves

Abstract

This invention belongs to the technical field of roller press sleeve manufacturing and discloses a method for rapid prototyping of maintenance-free wear-resistant roller sleeves using powder-free hot isostatic pressing. The method includes: designing the wear-resistant roller sleeve as comprising a substrate, an annular porous support plate, an annular porous easy-grind plate, and wear-resistant blocks; selecting appropriate material systems for each component based on its operating conditions; designing the arrangement of the wear-resistant blocks; machining the components and performing overall assembly; performing sealing welding, vacuuming, and leak detection; and then completing the hot isostatic pressing process; removing the sheath and performing machining and heat treatment to obtain the desired target part. This invention also discloses a corresponding maintenance-free wear-resistant roller sleeve product. Through this invention, the annular composite multi-layer porous plate can be fully utilized to replace tool steel powder in filling the gaps of the wear-resistant blocks, effectively overcoming many shortcomings of conventional hot isostatic pressing methods for processing wear-resistant roller sleeves, while also possessing advantages such as easy operation, high processing efficiency, and low cost.

Description

Technical Field

[0001] This invention belongs to the technical field of roller press sleeve preparation, and more specifically, relates to a method and product for rapid forming of maintenance-free wear-resistant roller sleeves using powder-free hot isostatic pressing. Background Technology

[0002] In mineral processing, roller presses are the most commonly used equipment. Roller presses primarily rely on two horizontally mounted, synchronously rotating, opposing extrusion rollers to crush materials under high pressure. The core component of the extrusion rollers is the outer roller sleeve, whose surface is generally required to have a staggered pattern to increase its gripping ability on the material. The roller sleeve directly contacts the material, and the high-pressure crushing force is transmitted to the material through the roller sleeve. As the enclosed material layer is forced to move downwards, the compressive pressure gradually increases until it is crushed and discharged from the bottom of the machine.

[0003] Common types of traditional roller press sleeves include: overlay welded sleeves, centrifugally cast sleeves, and carbide stud sleeves. During use, traditional overlay welded sleeves develop defects such as wear, pitting, and peeling; carbide stud sleeves experience wear, stud loss, and broken studs. These defects reduce the roller press's ability to draw material in, directly leading to lower crushing efficiency. Therefore, traditional sleeves require frequent repairs. This not only affects the roller press's uptime and increases operating costs, but also generates significant amounts of dust and fumes during repairs, creating a harsh working environment that harms the health of workers and the environment.

[0004] Therefore, it is necessary to improve the structure and manufacturing process of traditional roller sleeves and develop and manufacture maintenance-free wear-resistant roller sleeves. Patent searches revealed that, for example, patent US006086003A proposes a method for integrally forming wear-resistant roller sleeves using hot isostatic pressing (HIP). This wear-resistant roller sleeve consists of an array of cemented carbide wear-resistant blocks arranged on the surface of a substrate, with tool steel powder filling the gaps between the wear-resistant blocks. The assembly of all three materials is completed within the sleeve. HIP achieves a metallurgical bond between the cemented carbide, tool steel powder, and the substrate, ultimately forming a maintenance-free wear-resistant roller sleeve. After HIP, the wear-resistant layer of the roller sleeve comprises cemented carbide wear-resistant blocks and nearly fully dense tool steel powder.

[0005] However, further research has shown that the aforementioned existing technologies still have the following problems:

[0006] (i) Due to the small gap between the wear-resistant blocks, it is impossible to ensure that the tool steel powder fills the gap smoothly and evenly during the filling process; (ii) The cost of tool steel powder is relatively high, resulting in excessively high development costs for the wear-resistant roller sleeve; (iii) The pretreatment of the hot isostatic pressing process requires vacuuming the inside of the sleeve. Filling a large amount of powder will increase the vacuuming time and prolong the production cycle; (iv) During the hot isostatic pressing process, under the action of high temperature and high pressure, the sleeve shrinks and deforms, and the powder gradually becomes dense from loose. If the deformation is too large, it will increase the risk of sleeve breakage and lead to failure of the roller sleeve processing; (v) In order to ensure that the tool steel powder fills the gap between the wear-resistant blocks smoothly, the gap between the end face of the wear-resistant block and the sleeve is often increased. If the gap between the end face of the wear-resistant block and the sleeve is too large, it will result in too much tool steel covering the outer end face of the wear-resistant block after hot isostatic pressing, which increases the time and cost of subsequent machining to remove excess tool steel (machining to remove excess tool steel until the end face of the wear-resistant block is exposed).

[0007] Therefore, further research and improvements are urgently needed in this field to effectively solve the above-mentioned technical problems. Summary of the Invention

[0008] To address the aforementioned deficiencies or needs of existing technologies, the present invention aims to provide a method and product for rapid, powder-free hot isostatic pressing (HIP) forming of maintenance-free wear-resistant roller sleeves. By redesigning the entire manufacturing process and the roller sleeve structure, the invention fully utilizes annular composite multilayer perforated plates to replace tool steel powder in filling the gaps of the wear-resistant blocks, effectively overcoming the various shortcomings of conventional HIP processing of wear-resistant roller sleeves. It also offers advantages such as ease of operation, high processing efficiency, and low cost.

[0009] To achieve the above objectives, according to one aspect of the present invention, a method for rapid prototyping of maintenance-free wear-resistant roller sleeves using powder-free hot isostatic pressing is provided, characterized in that the method comprises the following steps:

[0010] Step 1: Material System Selection

[0011] The wear-resistant roller sleeve is designed to include a base, an annular porous support plate, an annular porous wear-resistant plate, and wear-resistant blocks arranged sequentially, with the wear-resistant blocks embedded in the holes of the annular porous support plate and the annular porous wear-resistant plate; appropriate material systems are selected for the above components according to the working conditions required for the wear-resistant roller sleeve.

[0012] Step 2: Design of Wear-Resistant Block Layout

[0013] By analyzing factors such as the usage environment and service life of the wear-resistant roller sleeve, multiple parameters including the size, thickness, vertical spacing, and horizontal spacing of the wear-resistant blocks are calculated, and then the three-dimensional model of the arrangement of the wear-resistant blocks is determined.

[0014] Step 3: Design and fabrication of the annular porous support plate and the annular porous easy-grinding plate.

[0015] Based on the wear-resistant block parameters determined in step two, the corresponding three-dimensional models of the annular porous support plate and the annular porous easy-to-grind plate are determined; then, based on the three-dimensional models, the porous straight plate is processed into the corresponding annular porous support plate and the annular porous easy-to-grind plate using the plate rolling process.

[0016] Step 4: Assemble the wear-resistant roller sleeve as a whole

[0017] After the processed annular porous support plate, annular porous easy-grind plate, substrate, and wear-resistant blocks are cleaned and dried, they are assembled into a package. The annular porous support plate surrounds the outer layer of the substrate, the annular porous easy-grind plate surrounds the outer layer of the annular porous support plate, and the wear-resistant blocks are respectively embedded in the corresponding holes of the annular porous support plate and the annular porous easy-grind plate.

[0018] Step 5: Hot Isostatic Pressing

[0019] The above-mentioned sheath is placed in a heat treatment furnace, and the inside of the sheath is vacuumed, sealed, and leak-tested. The treated sheath is then subjected to a hot isostatic pressing process, which combines the substrate, the annular porous support plate, the annular porous wear-resistant plate, and the wear-resistant block into a whole. The sheath is then removed, thereby obtaining the required maintenance-free wear-resistant roller sheath.

[0020] More preferably, in step one, the material of the substrate is preferably alloy structural steel or hot work die steel, including 30Cr2Ni2Mo alloy structural steel, 30Mn2MoW alloy structural steel, 5CrNiMo hot work die steel, 5CrMnMo hot work die steel, etc.; the material of the wear-resistant block is preferably cemented carbide, including YG8, YG15, YW1, YT15, etc.; the material of the annular porous support plate is preferably high-speed steel, such as M20, W18Cr4V, W6Mo5Cr4V, W9Mo3Cr4V, etc.; the material of the annular porous easy-grind plate is preferably stainless steel or carbon steel, including 304 stainless steel, 201 stainless steel, Q195, Q215, etc.

[0021] More preferably, in step two, the wear-resistant block is preferably hexagonal, rhomboid, square, or circular in shape; the total area of ​​the wear-resistant block preferably accounts for 50% to 90% of the total surface area of ​​the wear-resistant layer; furthermore, the size of the wear-resistant block is preferably within 1 cm². 2 ~30cm 2 Its thickness is preferably between 5mm and 40mm.

[0022] More preferably, in step three, the thickness of the annular porous support plate is preferably 5mm to 20mm, and the thickness of the annular porous easy-grind plate is preferably 1mm to 5mm; in addition, the machining allowance of the holes through the annular porous support plate and the annular porous easy-grind plate for installing the wear-resistant block is 1mm to 3mm.

[0023] More preferably, in step three, laser technology is preferably used to process the holes for mounting the wear-resistant block, wherein the laser processing parameters include the following: cutting speed of 0.8 mm / min to 1.0 mm / min, and laser power of 300 W to 500 W.

[0024] More preferably, in step five, the heating temperature of the heat treatment furnace is preferably 400℃~800℃, and the heating time is 12h~48h; during sealing, the vacuum degree inside the casing is preferably 10. -3 Pa~10 -4 Pa.

[0025] More preferably, in step five, the hot isostatic pressing process parameters include: a hot isostatic pressing temperature of 800℃~1400℃, a pressure of 100MPa~150MPa, and a heat and pressure holding time of 2h~10h.

[0026] More preferably, in step five, after removing the sleeve, heat treatment such as quenching, tempering, and annealing is also included to improve the surface hardness of the roller sleeve and eliminate residual stress.

[0027] According to another aspect of the invention, a corresponding powder-free, maintenance-free, wear-resistant roller sleeve product is also provided.

[0028] As a further preferred embodiment, after the above-mentioned hot isostatic pressing is completed, the surface hardness of the substrate of the wear-resistant roller sleeve product can reach 35HRC to 45HRC, the surface hardness of the wear-resistant block can reach 86HRA to 92HRA, the surface hardness of the annular porous support plate can reach 50HRC to 65HRC, and the surface hardness of the annular porous easy-to-wear plate is 200HV to 220HV.

[0029] In summary, the technical solutions conceived by this invention have the following main technical advantages compared with the prior art:

[0030] (1) This invention redesigns the entire preparation process route mechanism and roller sleeve structure, which can effectively utilize the annular composite multi-layer porous plate to replace tool steel powder to fill the gaps of wear-resistant blocks. The annular porous composite multi-layer plate is divided into one or more annular porous support plates that are closely attached to the substrate and an outer annular porous easy-grind plate that is closely attached to the annular porous support plate. The annular porous support plate can not only connect the substrate and the hard alloy wear-resistant block, but also fix and support the wear-resistant block. The annular porous easy-grind plate is made of a low-hardness material. During the grinding of ore, the annular porous easy-grind plate is easily ground off. The ore raw material will replace the porous easy-grind plate to fill the gaps of the wear-resistant blocks and be compacted to form a pad with strong anti-destruction ability, thereby reducing the wear degree of the porous support plate.

[0031] (2) Compared with the powder filling method of the prior art, the porous support plate of the present invention has a lower cost and reduces manufacturing costs. Furthermore, the porous support plate has a low porosity and a small specific surface area, which reduces the vacuuming time and shortens the pretreatment period of hot isostatic pressing. In addition, the porous support plate hardly undergoes shrinkage deformation during the hot isostatic pressing process, and there is no risk of the sheath breaking.

[0032] (3) The process flow of the present invention does not need to consider the problem of uneven powder filling during the powder filling process, and no vibration is required, saving time; in addition, the sleeve does not need to reserve deformation amount, and the sleeve can be obtained by simple machining after hot isostatic pressing;

[0033] (4) The present invention further improves the design of several key process parameters. Many actual tests show that the required wear-resistant roller sleeve can be obtained in a high-efficiency, high-quality and easy-to-control manner. The wear-resistant roller sleeve has the advantages of high strength, high hardness and high wear resistance. Attached Figure Description

[0034] Figure 1 This is an overall process flow diagram of the powder-free hot isostatic pressing rapid prototyping of maintenance-free wear-resistant roller sleeves according to the present invention;

[0035] Figure 2 This is an illustrative diagram showing the assembly of the wear-resistant roller sleeve in this invention;

[0036] Figure 3 This is a schematic diagram illustrating the wear-resistant roller sleeve slice in this invention.

[0037] Figure 4 This is a diagram illustrating the arrangement of the wear-resistant blocks in this invention.

[0038] Figure 5 This is an assembly diagram used to exemplify the insertion of the wear-resistant roller sleeve into the sleeve in this invention;

[0039] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0040] 1-Base; 2-Annular porous support plate; 3-Annular porous easy-to-grind plate; 4-Wear-resistant block; 5-Inner liner of the sheath; 6-Outer sheath of the sheath; 7-Wear-resistant roller sleeve. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Figure 1 This is a schematic process flow diagram of the hot isostatic pressing rapid prototyping of maintenance-free wear-resistant roller sleeves according to the present invention. The following will be combined with... Figure 1 To explain the invention in more detail.

[0043] First, there is the step of selecting the material system.

[0044] In this step, a suitable material system is selected based on the operating conditions of the wear-resistant roller sleeve:

[0045] The base material can be alloy structural steel or hot work die steel, such as 30Cr2Ni2Mo alloy structural steel, 30Mn2MoW alloy structural steel, 5CrNiMo hot work die steel, 5CrMnMo hot work die steel, etc., and its surface hardness can reach 35HRC~45HRC after hot isostatic pressing; the wear-resistant block material can be cemented carbide, such as YG8, YG15, YW1, YT15, etc., and its surface hardness can reach 86HRA~92HRA after hot isostatic pressing; the annular porous support plate material can be high-speed steel, such as M20, W18Cr4V, W6Mo5Cr4V, W9Mo3Cr4V, etc., and its surface hardness can reach 50HRC~65HRC after hot isostatic pressing; the annular porous easy-grind plate material can be stainless steel or carbon steel, such as 304 stainless steel, 201 stainless steel, Q195, Q215, etc., and its surface hardness is 200HV~220HV after hot isostatic pressing.

[0046] Next is the design step for the arrangement of wear-resistant blocks.

[0047] In this step, by combining actual working conditions of the wear-resistant roller sleeve with simulation, suitable parameters such as the size, thickness, vertical spacing, and horizontal spacing of the wear-resistant blocks are calculated. The shape of the wear-resistant blocks can be freely varied, including hexagonal, rhomboid, square, or circular shapes; the total area of ​​the wear-resistant blocks accounts for 50% to 90% of the total surface area of ​​the wear-resistant layer; the size of the wear-resistant blocks is typically 1 cm². 2 ~30cm 2 The thickness of the wear-resistant blocks can vary between 5mm and 40mm to accommodate the diameter of the roller sleeve and the required service life. After determining the parameters, a 3D model of the wear-resistant block arrangement is created using the 3D modeling software UG.

[0048] Next are the design and processing steps for the annular porous support plate and the annular porous easy-grind plate.

[0049] In this step, based on the parameters of the wear-resistant block, for example, Boolean difference operations can be performed on the wear-resistant block, support plate, and easy-to-grind plate using 3D modeling software UG to obtain 3D models of the annular porous support plate and the annular porous easy-to-grind plate. Then, UG is used to unfold the annular porous support plate and the annular porous easy-to-grind plate into a porous straight plate, finally obtaining the machining drawing of the porous straight plate. Here, the diameter of the hole needs to be increased or decreased by 1mm to 3mm to ensure that the wear-resistant block can be embedded in the hole.

[0050] According to the processing drawings, holes are machined into the steel plate using laser cutting. The laser cutting speed is 0.8mm / min to 1.0mm / min, and the laser power is 300W to 500W. The perforated straight plate is then processed into annular perforated support plates and annular perforated easy-grinding plates using a plate rolling process.

[0051] Next comes the assembly of the wear-resistant roller sleeve and the pretreatment steps of hot isostatic pressing.

[0052] In this step, an ultrasonic cleaner is used to clean the oil stains from the surfaces of the base material, wear-resistant blocks, annular porous support plate, and annular porous easy-grip plate. After drying the surface moisture using an oven heated to 100°C, the materials are assembled. The inner liner of the casing is passed through the inner hole of the base material and welded to the lower cover of the casing to form a single unit. The annular porous support plate surrounds the outer layer of the base material, and the annular porous easy-grip plate surrounds the outer layer of the porous support plate. The wear-resistant blocks are then embedded into the holes of the annular porous support plate and the annular porous easy-grip plate, and the outer casing and the upper cover are then sealed and welded together.

[0053] The sealed casing is placed in a heating furnace and vacuumed inside the casing using a molecular pump through a vacuum tube at a high temperature of 400℃~800℃, and maintained at this temperature for 12h~48h. When the vacuum level inside the casing decreases to 10... -3 Pa~10 - 4Pa, the extraction pipe was sealed using argon arc welding. After the entire casing was sealed, a helium mass spectrometer was used to check for leaks in the entire casing to ensure that there were no leaks.

[0054] Next is the hot isostatic pressing process.

[0055] In this step, the leak-tested roller sleeve is placed in a hot isostatic pressing furnace, heated to 800℃~1400℃, pressurized to 100MPa~150MPa, and held at the temperature and pressure for 2h~10h. During this process, the wear-resistant block, the annular porous support plate, the annular porous easy-grip plate, and the substrate are metallurgically bonded together, thereby forming a maintenance-free wear-resistant roller sleeve.

[0056] Finally, there are machining steps to remove the cladding and heat treatment steps.

[0057] In this step, the sleeve is removed by machining and then heat-treated. Because the sleeve has a regular geometry and the interior is a regular annular workpiece, it retains its regular geometry after hot isostatic pressing. Conventional machining methods can be used to remove the sleeve, followed by heat treatments such as quenching, tempering, and annealing, thereby increasing the surface hardness of the sleeve and eliminating residual stress.

[0058] Based on the above concept, the annular porous composite multilayer plate proposed in this invention consists of one or more annular porous support plates tightly attached to the substrate, and an outer annular porous easy-grinding plate tightly attached to the annular porous support plate. The annular porous support plate serves to connect the substrate and the hard alloy wear-resistant blocks, and also to fix and support the wear-resistant blocks. The annular porous easy-grinding plate is made of a low-hardness material. During the ore grinding process, the porous easy-grinding plate is easily worn away, and the ore raw material replaces the porous easy-grinding plate, filling the gaps between the wear-resistant blocks and being compacted to form a pad with strong anti-destruction capabilities, thereby reducing the wear degree of the porous support plate. As for the wear-resistant blocks, they are embedded in the holes of the porous support plate and the porous easy-grinding plate. Through hot isostatic pressing, the wear-resistant blocks, the annular porous support plate, the annular porous easy-grinding plate, and the substrate are metallurgically bonded, ultimately forming a maintenance-free wear-resistant roller sleeve.

[0059] The present invention will be illustrated below with several specific embodiments.

[0060] Example 1

[0061] The present invention is used to manufacture a cement roller press sleeve (model HFCG120-50) with an outer diameter of 1200mm, an inner diameter of 700mm, and a height of 500mm as an example.

[0062] (1) The matrix is ​​made of 30Cr2Ni2Mo alloy structural steel, and its surface hardness can reach 45HRC after hot isostatic pressing; the wear-resistant block is made of YG8 hard alloy steel, which has high hardness and high wear resistance, and its surface hardness can reach 89HRA after hot isostatic pressing; the annular porous support plate is made of M20 high-speed steel, and its surface hardness can reach 60HRC after hot isostatic pressing; the annular porous easy-grind plate is made of 304 stainless steel, and its surface hardness is 210HV after hot isostatic pressing. The purpose of using 304 stainless steel to process the porous easy-grind plate is that during the grinding of ore, the porous easy-grind plate is easily worn away, and the ore raw material will replace the porous easy-grind plate to fill the gap of the wear-resistant block and be compacted to form a pad with strong anti-destruction ability, thereby reducing the wear degree of the porous support plate.

[0063] (2) The base dimensions of the wear-resistant roller sleeve are: Φ1200mm×Φ700mm×500mm. Wear-resistant blocks come in two sizes, such as... Figure 4 As shown: 1. The shape is a regular hexagonal prism, with a side length of 16mm, a height of 10mm, and an area of ​​6.7cm². 2 2. The shape is a cuboid, with a length of 16mm, a width of 8mm, a height of 10mm, and an area of ​​1.28cm². 2 The six vertical edges of the regular hexagonal prism and the four vertical edges of the cuboid wear-resistant block are rounded by 2mm. The thickness of the porous support plate is 8mm, and the thickness of the porous easy-to-grind plate is 2mm.

[0064] Based on the parameters of the wear-resistant block, Boolean difference operations were performed on the wear-resistant block, support plate, and easy-to-grind plate using the 3D modeling software UG to obtain 3D models of the annular porous support plate and the annular porous easy-to-grind plate. Then, UG was used to unfold the annular porous support plate and the annular porous easy-to-grind plate into a porous straight plate, finally obtaining the machining drawing for the porous straight plate. Here, the diameter of the holes was increased by 2mm to ensure that the wear-resistant block could be embedded in the holes. According to the machining drawing, holes to accommodate the wear-resistant block were machined on an M20 high-speed steel plate and a 304 stainless steel plate using laser cutting. The laser cutting speed was 0.8mm / min, and the laser power was 500W.

[0065] (3) The perforated straight plate is processed into annular perforated support plates and annular perforated easy-to-grind plates using a plate rolling process. An ultrasonic cleaner is used to clean the oil stains from the surfaces of the substrate material, wear-resistant blocks, annular perforated support plates, and annular perforated easy-to-grind plates. The surface moisture is then dried using an oven heated to 100°C. The inner liner of the casing is passed through the inner hole of the substrate material and welded to the lower cover of the casing to form a single unit. The annular perforated support plate surrounds the outer layer of the substrate, and the annular perforated easy-to-grind plate surrounds the outer layer of the perforated support plate. Wear-resistant blocks are embedded into the holes of the perforated support plate and the perforated easy-to-grind plate, and the outer casing and the upper cover are then sealed and welded together.

[0066] The entire casing was placed in a heat treatment furnace and heated to 600℃ to remove residual contaminants and moisture from its surface. A molecular pump connected to a vacuum pipe was then used for degassing for approximately 20 hours. The process continued until the vacuum level inside the casing decreased to 10... -3 At approximately 1000 Pa, the extraction pipe was sealed using argon arc welding. After the entire sheath was sealed, a helium mass spectrometer was used to check for leaks in the sheath to ensure there were no leaks.

[0067] (4) The pre-treated sleeve is subjected to hot isostatic pressing (HIP). The sleeve is placed in a hot isostatic pressing furnace, heated to 1000℃ and pressurized to 120MPa, held at the temperature and pressure for 6 hours, and then removed after returning to normal temperature and pressure. Because the sleeve has a regular geometric shape and the inside of the sleeve is a circular wear-resistant roller sleeve, it still maintains its regular assembly shape after hot isostatic pressing. The sleeve is then removed using simple machining.

[0068] (5) After rough machining, the roller sleeve undergoes flaw detection. Once the flaw detection is successful, heat treatment is performed, including quenching and three tempering processes. First, quenching is performed by placing the roller sleeve in a resistance furnace and heating it from room temperature to 800℃, holding it at that temperature for 16 hours. Then, it is heated at 80℃ / h to 1150℃ and held for 1 hour, followed by air cooling to room temperature. Next, the roller sleeve is tempered. It is placed in a resistance furnace and heated from room temperature to 540℃ at 20℃ / h, holding it at that temperature for 20 hours. The furnace is then cooled to room temperature, and this tempering process is repeated three times. After heat treatment, residual stress is eliminated, processing performance is improved, and the problem of large differences in the thermal expansion coefficients of different metal layers is solved. Upon completion of the heat treatment, a maintenance-free, wear-resistant roller sleeve is obtained.

[0069] Example 2

[0070] The present invention is used to manufacture a cement roller press sleeve (model HFCG180-120) with an outer diameter of 1800mm, an inner diameter of 1200mm, and a height of 1200mm as an example.

[0071] (1) The matrix is ​​made of 5CrNiMo hot work die steel, and its surface hardness can reach 35HRC after hot isostatic pressing; the wear-resistant block is made of YG15 cemented carbide steel, which has high hardness and high wear resistance, and its surface hardness can reach 92HRA after hot isostatic pressing; the annular porous support plate is made of W18Cr4V high-speed steel, and its surface hardness can reach 60HRC after hot isostatic pressing; the annular porous easy-grind plate is made of 201 stainless steel, and its surface hardness is 200HV after hot isostatic pressing. The purpose of using 201 stainless steel to process the porous easy-grind plate is that during the grinding of ore, the porous easy-grind plate is easily worn away, and the ore raw material will replace the porous easy-grind plate to fill the gap of the wear-resistant block and be compacted to form a pad with strong anti-destruction ability, thereby reducing the wear degree of the porous support plate.

[0072] (2) The base dimensions of the wear-resistant roller sleeve are: Φ1800mm×Φ1200mm×1200mm. Wear-resistant blocks come in two sizes, such as... Figure 4 As shown: 1. The shape is a regular hexagonal prism, with a side length of 30mm, a height of 17mm, and an area of ​​23.4cm². 2 2. The shape is a cuboid, with a length of 30mm, a width of 10mm, a height of 17mm, and an area of ​​3cm². 2 The six vertical edges of the regular hexagonal prism and the four vertical edges of the cuboid wear-resistant block are rounded by 2mm. The thickness of the porous support plate is 15mm, and the thickness of the porous easy-to-grind plate is 2mm.

[0073] Based on the dimensional parameters of the wear-resistant block, Boolean difference operations were performed on the wear-resistant block, support plate, and easy-grinding plate using the 3D modeling software UG to obtain 3D models of the annular porous support plate and the annular porous easy-grinding plate. Then, UG was used to unfold the annular porous support plate and the annular porous easy-grinding plate into a porous straight plate, finally obtaining the machining drawing for the porous straight plate. Here, the hole size was increased by 2mm to ensure that the wear-resistant block could be embedded in the hole. According to the machining drawing, holes to accommodate the wear-resistant block were machined on a W18Cr4V high-speed steel plate and a 201 stainless steel plate using laser cutting. The laser cutting speed was 0.8mm / min, and the laser power was 500W.

[0074] (3) The perforated straight plate is processed into annular perforated support plates and annular perforated easy-wear plates using a plate rolling process. Since the thickness of the annular perforated support plate is 15mm, the steel thickness is too thick, which poses difficulties during the plate rolling process. Therefore, three 5mm steel plates are used to replace the 15mm steel plates to form a three-layer annular perforated support plate. Special attention should be paid to the matching of the holes to ensure that the wear-resistant blocks can be smoothly embedded into the holes of the four layers of rolled plates.

[0075] The oil stains on the surfaces of the base material, wear-resistant blocks, annular porous support plate, and annular porous easy-grip plate are cleaned using an ultrasonic cleaner, and the surface moisture is dried using an oven heated to 100°C. The inner liner of the casing is passed through the inner hole of the base material and welded to the lower cover of the casing to form a single unit. The annular porous support plate surrounds the outer layer of the base material, and the annular porous easy-grip plate surrounds the outer layer of the porous support plate. The wear-resistant blocks are embedded into the holes of the porous support plate and the porous easy-grip plate, and the outer casing and the upper cover are then sealed and welded together.

[0076] The entire casing was placed in a heat treatment furnace and heated to 600℃ to remove residual contaminants and moisture from its surface. A molecular pump connected to a vacuum pipe was then used for degassing for approximately 36 hours. When the vacuum level inside the casing decreased to 10... -3 At approximately 1000 Pa, the extraction pipe was sealed using argon arc welding. After the entire sheath was sealed, a helium mass spectrometer was used to check for leaks in the sheath to ensure there were no leaks.

[0077] (4) The pre-treated sleeve is subjected to hot isostatic pressing (HIP). The sleeve is placed in a hot isostatic pressing furnace, heated to 1000℃ and pressurized to 120MPa, held at the temperature and pressure for 6 hours, and then removed after returning to normal temperature and pressure. Because the sleeve has a regular geometric shape and the inside of the sleeve is a circular wear-resistant roller sleeve, it still maintains its regular assembly shape after hot isostatic pressing. The sleeve is then removed using simple machining.

[0078] (5) After rough machining, the roller sleeve undergoes flaw detection. Once the flaw detection is successful, heat treatment is performed, including quenching and three tempering processes. First, quenching is performed by placing the roller sleeve in a resistance furnace and heating it from room temperature to 800℃ for 20 hours, then heating it at 80℃ / h to 1150℃ for 1 hour, followed by air cooling to room temperature. Then, the roller sleeve is tempered. It is placed in a resistance furnace and heated from room temperature to 540℃ at 20℃ / h for 24 hours, then cooled to room temperature. This tempering process is repeated three times. After heat treatment, residual stress is eliminated, processing performance is improved, and the problem of large differences in the thermal expansion coefficients of different metal layers is solved. After heat treatment, a maintenance-free, wear-resistant roller sleeve is obtained.

[0079] In summary, this invention redesigns the entire manufacturing process and the structure of the roller sleeve, effectively utilizing annular composite multilayer perforated plates to replace tool steel powder in filling the gaps of the wear-resistant blocks. It also effectively overcomes many shortcomings of conventional hot isostatic pressing methods for processing wear-resistant roller sleeves, thus possessing broad application prospects.

[0080] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for rapid prototyping of powder-free, hot isostatic pressing, maintenance-free, wear-resistant roller sleeves, characterized in that... The method includes the following steps: Step 1: Material System Selection The wear-resistant roller sleeve is designed to include a base, an annular porous support plate, an annular porous wear-resistant plate, and a wear-resistant block arranged sequentially, with the wear-resistant block embedded in the holes of the annular porous support plate and the annular porous wear-resistant plate; and appropriate material systems are selected for the base, annular porous support plate, annular porous wear-resistant plate, and wear-resistant block respectively, according to the operating conditions required for the wear-resistant roller sleeve. Step 2: Design of Wear-Resistant Block Layout By analyzing factors such as the usage environment and service life of the wear-resistant roller sleeve, multiple parameters including the size, thickness, vertical spacing, and horizontal spacing of the wear-resistant blocks are calculated, and then the three-dimensional model of the arrangement of the wear-resistant blocks is determined. Step 3: Design and fabrication of the annular porous support plate and the annular porous easy-grinding plate. Based on the relevant parameters of the wear-resistant block determined in step two, the corresponding three-dimensional models of the annular porous support plate and the annular porous easy-to-grind plate are determined; then, based on the three-dimensional models, the porous straight plate is processed into the corresponding annular porous support plate and annular porous easy-to-grind plate using the plate rolling process. Step 4: Assemble the wear-resistant roller sleeve as a whole After the processed annular porous support plate, annular porous easy-grind plate, substrate, and wear-resistant block are cleaned and dried, they are assembled into a package. The annular porous support plate surrounds the outer layer of the substrate, the annular porous easy-grind plate surrounds the outer layer of the annular porous support plate, and the wear-resistant block is embedded in the corresponding holes of the annular porous support plate and the annular porous easy-grind plate. Step 5: Hot Isostatic Pressing Treatment The sleeve is placed in a heat treatment furnace, and the inside of the sleeve is vacuumed, sealed, and leak-tested. The treated sleeve is then subjected to hot isostatic pressing, which combines the substrate, the annular porous support plate, the annular porous wear-resistant plate, and the wear-resistant block into a whole. The sleeve is then removed to obtain the required maintenance-free wear-resistant roller sleeve.

2. The method as described in claim 1, characterized in that, In step two, the shape of the wear-resistant block is in the form of a hexagon, a rhombus, a square or a circle; the total area of the wear-resistant block accounts for 50% to 90% of the total surface area of the wear-resistant layer; the size of the area of the wear-resistant block is between 1 cm 2 ~30 cm 2 , and its thickness is between 5 mm and 40 mm.

3. The method as described in claim 2, characterized in that, In step three, the thickness of the annular porous support plate is 5 mm to 20 mm, and the thickness of the annular porous easy-grind plate is 1 mm to 5 mm; the machining allowance for the holes through the annular porous support plate and the annular porous easy-grind plate used to install the wear-resistant block is 1 mm to 3 mm.

4. The method as described in claim 3, characterized in that, In step three, laser cutting is used to process the holes for mounting the wear-resistant blocks. The laser processing parameters include the following: cutting speed of 0.8 mm / min to 1.0 mm / min and laser power of 300 W to 500 W.

5. The method as described in claim 4, characterized in that, In step five, the heating temperature of the heat treatment furnace is 400℃~800℃, and the heating time is 12 h~48 h; during sealing, the vacuum degree inside the casing is 10. -3 Pa~10 -4 Pa.

6. The method as described in claim 5, characterized in that, In step five, the hot isostatic pressing process parameters include: a hot isostatic pressing temperature of 800 ℃~1400 ℃, a pressure of 100 MPa~150 MPa, and a holding time of 2 h~10 h.

7. The method as described in claim 6, characterized in that, In step five, after removing the sleeve, heat treatments such as quenching, tempering, and annealing are also included to improve the surface hardness of the roller sleeve and eliminate residual stress.

8. A powder-free, maintenance-free, wear-resistant roller sleeve product, characterized in that, It is prepared by means of any one of claims 1-7.

9. The powder-free, maintenance-free, wear-resistant roller sleeve product as described in claim 8, characterized in that, After the above-mentioned hot isostatic pressing is completed, the surface hardness of the wear-resistant roller sleeve product is 35 HRC~45 HRC, the surface hardness of the wear-resistant block is 86 HRA~92 HRA, the surface hardness of the annular porous support plate is 50 HRC~65 HRC, and the surface hardness of the annular porous easy-wear plate is 200 HV~220 HV.

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