Low-heat efficient steel rail cutting blade for railway steel rail cutting and manufacturing method of low-heat efficient steel rail cutting blade

Abstract

The invention discloses a low-heat efficient steel rail cutting blade for railway steel rail cutting and a manufacturing method of the low-heat efficient steel rail cutting blade, and belongs to the technical field of tools for grinding, polishing or cutter grinding. The low-heat efficient steel rail cutting blade is prepared from the following raw materials in parts by mass: 100 to 135 parts of grinding material, 10 to 20 parts of resin adhesive, 20 to 30 parts of functional filler, 4 to 8 parts of self-lubricating pore-forming material and 3 to 5 parts of wetting agent. The steel rail cutting fluid has good cutting performance and anti-burn performance, 60 # steel rails can be cut at a time within 90 s, it is guaranteed that no obvious burn exists on the cutting face, and the steel rail cutting machining tolerance requirement is met.

Description

Technical Field

[0001] The present invention relates to the technical field of tools for grinding, polishing or edge grinding, and particularly relates to a low-heat and high-efficiency rail cutting disc for railway rail cutting and a manufacturing method thereof. Background Art

[0002] With the continuous expansion of the scale of the railway network and the continuous breakthrough of the train operation speed, more stringent technical requirements are put forward for the processing quality and cutting efficiency of railway rails. The material of railway rails has characteristics such as high strength, high hardness and good toughness, resulting in a significant increase in the difficulty of its cutting processing. At present, the key processing equipment and consumables in the industry are still monopolized by imported products for a long time. Although they have advantages in cutting efficiency and service life, there are problems such as high procurement costs, unstable supply cycles and being restricted by others in core technologies, which seriously restrict the optimization of local railway construction costs and the development process of the independent technology system.

[0003] Although some technological breakthroughs have been achieved in related fields in recent years, there are still severe challenges at the practical application level. Specifically, there are still obvious gaps in the cutting efficiency, processing accuracy and surface quality of domestic cutting tools, which are prominently manifested as problems such as cross-section burns and burrs easily generated during the cutting process, resulting in the difficulty of the processed rail cross-section to meet the process specification requirements. This not only increases the subsequent processing costs, but also poses potential risks to railway operation safety. From the perspective of technology research and development, the existing cutting disc formula system and production process mostly follow the traditional technical route, and there has been no breakthrough progress in the aspects of material science and process innovation, making it difficult to meet the requirements of high-efficiency and precision processing of modern railway rails. This technical bottleneck has become a key factor restricting the overall upgrading of the industry.

[0004] The applicant's R & D team disclosed a self-lubricating composite filler for resin-based grinding wheels and its preparation method in a Chinese patent with the publication number CN116038582A. This solution bonds solid lubricants and mechanically crushes them to prepare the self-lubricating composite filler. The surface of the crushed self-lubricating composite filler is chemically plated, and the surface is irregular with a large number of protruding fibers, which can be anchored to the grinding wheel resin binder, increasing the bonding strength between the composite filler and the resin grinding wheel matrix. The resin-based self-lubricating composite filler can be released in real time in the grinding wheel / workpiece contact area along with the wear of the binder during the grinding process of the grinding wheel, thereby lubricating the contact area, reducing the generation of grinding heat, reducing the thermal damage to the workpiece caused by the grinding heat, and improving the surface machining quality of the workpiece. Not only that, in a Chinese patent with the publication number CN115741506A, the applicant's R & D team provided a resin-based self-lubricating grinding wheel with high strength and low burn and its preparation method. The self-lubricating composite filler used in this invention has a large number of protruding fibers on its surface, which can form anchor points with the resin binder, improving the bonding strength with the resin binder. At the same time, the surface of the self-lubricating particles is plated, improving the surface energy of the self-lubricating particles and making them easy to be infiltrated by the resin. The lubricating components are added to the resin-based grinding wheel in the form of lubricating powder and self-lubricating composite filler, increasing the addition amount of the lubricating components while ensuring that the grinding wheel has high mechanical properties. The lubricating components can be released in real time in the grinding wheel / workpiece contact area along with the wear of the binder during the grinding process of the grinding wheel, thereby lubricating the contact area, greatly reducing the heat generation during grinding, reducing the grinding temperature, and thus improving the thermal recession problem of the resin-based grinding wheel caused by high temperature.

[0005] In the further R & D process, the inventor team found that using fiber fillers as reinforcing agents to "anchor" the resin matrix through high aspect ratio fiber fillers to improve the strength of the resin matrix still fails to solve problems such as the easy stacking, difficult dispersion, and easy slippage of sheet structures of solid lubricating materials at high concentrations. In addition, considering the requirements for cutting force and edge retention of cutting discs, the matrix material can hardly withstand a higher content of solid self-lubricating materials, and the design of the grinding wheel components cannot be simply extended to the application of cutting discs. And compared with grinding wheel processing, the cutting disc also needs to meet indicators such as cutting surface perpendicularity, parallelism, and flatness after operation, which puts higher requirements on its design.

[0006] In summary, a low-heat and high-efficiency rail cutting disc for railway rails and its manufacturing method are proposed. By optimizing the formula and preparation process, the cutting efficiency, machining accuracy of the cutting disc are improved, the rail cutting burn is reduced, the production cost is lowered, meeting the high requirements of railway rail cutting processing, and playing an important promoting role in the development of the railway construction engineering field. Summary of the Invention

[0007] In view of the above-mentioned defects of the prior art, in the first aspect of the present invention, a low-heat and highly efficient rail cutting disc with high cutting efficiency, low heat generation, and excellent cutting quality is provided. In terms of parts by mass, its raw materials include: 100-135 parts of abrasive, 10-20 parts of resin binder, 20-30 parts of functional filler, 4-8 parts of self-lubricating pore-forming material, and 3-5 parts of wetting agent.

[0008] Preferably, the abrasive includes 30-40 parts of brown fused alumina, 60-80 parts of zirconium corundum, and 10-15 parts of cubic boron nitride.

[0009] Preferably, the resin binder includes phenolic resin powder.

[0010] Preferably, the functional filler includes 10-15 parts of precipitated barium sulfate, 3-5 parts of cryolite, 5-7 parts of pyrite powder, and 2-3 parts of calcium oxide.

[0011] Preferably, the self-lubricating pore-forming material is a carbamide graphite molybdenum disulfide composite filler particle; its components include a pore-forming component and a self-lubricating component; among them, the pore-forming component is carbamide, and the self-lubricating component is flake graphite powder and molybdenum disulfide powder.

[0012] Based on the application of the cutting disc, the present invention conducts specific design on the components. In the self-lubricating pore-forming material, there is no need to further add materials such as epoxy resin and aramid fiber, realizing component optimization. The cutting disc is a material that rotates at a high speed through the outer peripheral surface at a fixed position to achieve cutting. During the cutting process, it is only subjected to a single-directional force, that is, the force pointing from the rotation radius to the contact surface of the object to be cut; at the same time, the force applied to the cutting disc during the operation process is small to reduce the back engagement of the cutting edge and prevent dangerous situations such as chipping. Since the cutting disc operates at a fixed position without external force traction and movement, and the force during operation is small, the sensitivity of the cutting disc material to the pore structure is small, and there is no need to add aramid fiber as a reinforcing material; at the same time, since the pressure on the cutting disc during operation is small, there is no need to add epoxy resin to enhance the bearing capacity of the pores. The self-lubricating pore-forming filler prepared by melting is selected. Since it does not contain epoxy resin and aramid fiber, the content of the pore-forming component and the self-lubricating component in the self-lubricating pore-forming filler with the same particle size is higher, which is more conducive to the generation of pores and the release of self-lubricating materials. In summary, the self-lubricating pore-forming filler selected in the cutting disc material does not add aramid fiber and epoxy resin, and by maximizing the proportion of the pore-forming component and the self-lubricating component in the particle as much as possible, the functions of better friction reduction, heat dissipation, and accommodating large-volume chips are realized.

[0013] Further preferably, the preparation method of the carbamide graphite molybdenum disulfide composite filler particle includes the following steps: Mix the molten carbamide with flake graphite powder and molybdenum disulfide powder to complete the adhesion and encapsulation of the flake graphite powder and molybdenum disulfide powder. After cooling and forming, it is crushed and sieved to obtain carbamide graphite molybdenum disulfide composite filler particles.

[0014] Further preferably, in the carbamide graphite molybdenum disulfide composite filler particles, by mass, the proportion of each component is 30 - 40 parts of carbamide, 6 - 9 parts of graphite powder, and 4 - 6 parts of molybdenum disulfide powder.

[0015] The carbamide graphite molybdenum disulfide composite filler particles have hardness and strength that meet the application indicators at room temperature and can maintain their shape and size during the preparation of the cutting disc. During the firing and hardening process, the pore-forming material components decompose and leave regular pores of a certain size in the cutting disc, so that the self-lubricating components are released through the pores.

[0016] Preferably, the wetting agent includes phenolic resin liquid.

[0017] Preferably, the particle size of the resin binder is 280 - 350 mesh, the particle size of the abrasive is 16 - 24 mesh, the particle size of the self-lubricating pore-forming filler is 24 - 30 mesh, and the particle size of the functional filler is 100 - 150 mesh.

[0018] The mesh number of the self-lubricating pore-forming filler is selected based on the analysis of the chip size generated after on-site cutting and the adaptability with the abrasive size.

[0019] Based on the defined indicators of the above process, in actual operation, as presented in one or more embodiments of the present invention, the preparation of carbamide graphite molybdenum disulfide composite filler particles can be carried out according to the following steps or other suitable methods: 1) Weigh each raw material in proportion, ball-mill and mix the graphite powder and molybdenum disulfide powder to obtain a mixed component; the mixed component is kept warm at a certain temperature for standby; 2) Heat the carbamide to melting, and then keep stirring at the melting temperature; 3) Add the mixed component to the molten carbamide liquid, and after mixing and degassing, obtain a mixed component; 4) The mixed component is cooled and formed to obtain a formed component; the formed component is crushed and sieved to obtain carbamide graphite molybdenum disulfide composite filler particles.

[0020] In the second aspect of the present invention, a preparation method of the low-heat and high-efficiency rail cutting disc of the first aspect of the present invention is provided, including the following steps: (1)Weigh each raw material proportionally, mix brown fused alumina, zirconium corundum, and cubic boron nitride to obtain a mixed abrasive; add a self-lubricating pore-forming filler to the mixed abrasive and mix to obtain an abrasive component; mix the resin binder and the functional filler to make an auxiliary component; dry the abrasive component and the auxiliary component and place them in a constant temperature and humidity environment. (2)Add a wetting agent to the abrasive component and mix. After completion, add the auxiliary component and mix to make a mixed component; sieve the mixed component to obtain a loose cutting sheet component, and let it stand in a constant temperature and humidity environment after sieving. (3)Press the cutting sheet component and the fiber reinforcement mesh to form a cutting sheet molding sample; heat-press and sinter the cutting sheet molding sample to harden it to obtain a low-heat and high-efficiency rail cutting sheet.

[0021] During the preparation process, the self-lubricating pore-forming material has high hardness and compressive strength at room temperature, can withstand the pressure applied by the cutting sheet pressing process without breaking, and maintains its original size and morphology. During the firing and hardening process of the cutting sheet, at high temperature, the pore-forming material component in the self-lubricating pore-forming material decomposes, releasing the solid lubricant component in the self-lubricating pore-forming material. The solid lubricating material has high heat resistance and can maintain stable physical properties at the high-temperature hardening temperature of the cutting sheet. The pore-forming material component in the self-lubricating pore-forming material decomposes during the firing process of the cutting sheet, thus forming a pore structure in the cutting sheet, enabling the solid lubricant component to be released in the prepared pores after partial decomposition of the self-lubricating pore-forming material.

[0022] Based on the above technical solutions, the design concept and principle of the present invention are as follows: During actual operation, the abrasive in the cutting sheet mainly undergoes two effects during cutting: cutting and friction. The cutting effect can achieve the peeling of materials, while the friction effect is the main cause of heat generation. Traditional self-lubricating materials are usually directly added to the matrix material of the cutting sheet to achieve the release of the self-lubricating material during the cutting process. The drawback is that directly adding the self-lubricating material to the matrix material significantly reduces the mechanical strength and wear resistance of the cutting sheet, and significantly reduces the service life and safety performance of the cutting sheet.

[0023] In the present invention, a self-lubricating pore-forming material, namely, carbamide graphite molybdenum disulfide composite filler particles, is added to the traditional cutting disc material. The difference between the self-lubricating pore-forming material and the traditional self-lubricating material is that the self-lubricating pore-forming material forms pores through the decomposition of the pore-forming material components. The pore structure of the cutting disc can effectively accommodate the chips generated at the cutting disc / rail contact interface, which serve as high-temperature heat sources. After separating from the contact interface, under the action of the centrifugal force of the cutting disc, the chips, as high-temperature heat sources, are discharged in a timely manner. At the same time, the pores can effectively increase the exposed height of the abrasives in the cutting disc, improving the cutting performance of the abrasives. The solid lubricating material of the cutting disc is released through the pore structure on the cutting disc / rail contact surface and acts on the surface of the abrasives and the rail, enabling lubrication at the contact interface between the abrasives and the material and reducing frictional heat generation. The low-heat and high-efficiency rail cutting disc achieves the function of low heat generation through two methods: timely accommodating and discharging high-temperature heat sources and reducing heat generation at the source.

[0024] Compared with the prior art, the present invention has the following advantages and beneficial effects: The present invention provides a low-heat and high-efficiency rail cutting disc, which is characterized by high cutting efficiency, low heat generation, and excellent cutting quality, and has broad application prospects in railway rail cutting operations.

[0025] The present invention provides a preparation method for a low-heat and high-efficiency rail cutting disc. The process is simple and easy for batch production, which helps to realize the large-scale production of low-heat and high-efficiency rail cutting discs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is the physical appearance of Example 1; Figure 2 is the loss before and after one-pass cutting of Example 1; Figure 3 is the burn situation of the rail cutting surface after one-pass cutting of Example 1 and Comparative Example 1; Figure 4 is the perpendicularity situation of the rail cutting surface after one-pass cutting of Example 1 and Comparative Example 1; Figure 5 is the parallelism situation of the rail cutting surface after one-pass cutting of Example 1 and Comparative Example 1; Figure 6 is the flatness situation of the rail cutting surface after one-pass cutting of Example 1 and Comparative Example 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The present invention will be further described below by way of examples, but the present invention is not limited to the scope of the described examples. For the experimental methods without specific conditions noted in the following examples, they are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0028] Example 1 This embodiment provides a low-heat and high-efficiency rail cutting blade, and the preparation method thereof is as follows: (1) Preparation of self-lubricating pore-forming materials: 1) Weigh the raw materials in proportion, put 8 parts of graphite powder and 6 parts of molybdenum disulfide powder into a ball mill for ball milling and mixing, the ball mill speed is 300 rpm, and the ball-to-material ratio is 1:0.6; the particle size of graphite powder and molybdenum disulfide is above 200 mesh; after fully mixing, a solid component is obtained; the solid component is placed in an oven and heated to 145 ° C, and kept warm in the oven for use; 2) Heat 40 parts of carbonamide in an oven to 145°C; heat a constant temperature magnetic stirrer to 145°C, place carbonamide in the constant temperature magnetic stirrer, heat and stir until completely melted to obtain a carbonamide melt, and keep the melt at the melting temperature and rotate at a constant temperature; 3) Slowly pour the solid component into the carbonamide melt in 4 times, stir for 5 minutes after each pouring, and vacuum the material after sufficient stirring to remove bubbles generated during the stirring process to obtain a mixed component; 4) The mixed components are placed in an oven for cooling and molding at a cooling rate of 0.8 °C / min until the temperature reaches room temperature, thereby obtaining a molded component; the molded component is mechanically crushed and then sieved, and separated according to three gradients of 10-16 mesh, 16-24 mesh, and 24-36 mesh to obtain carbonamide graphite molybdenum disulfide composite filler particles with uniform particle size; (2) Premix: Weigh 35 parts of brown corundum, 75 parts of zirconium corundum, and 10 parts of cubic boron nitride and mix them; the mesh number of brown corundum is 24 mesh, the mesh number of zirconium corundum is 16 mesh, and the mesh number of cubic boron nitride is 20 mesh; send the abrasive into a mixer, mix for 5 minutes, and achieve full mixing to obtain a mixed abrasive; Weigh 8 parts of self-lubricating pore-forming filler; the mesh size of the carbonamide graphite molybdenum disulfide composite filler particles is 24 mesh; add the carbonamide graphite molybdenum disulfide composite filler particles to the above mixed abrasive, and mix them thoroughly for 3 minutes to prepare an abrasive component; Weigh 8 parts of phenolic resin powder, 3 parts of cryolite, 5.5 parts of pyrite, 2 parts of calcium oxide, and 10 parts of precipitated barium sulfate; the phenolic resin powder is selected to have a mesh size of 300 mesh and the functional filler is selected to have a mesh size of 150 mesh; send the phenolic resin powder and the functional filler into a drum mixer and mix them thoroughly for 5 hours to prepare an auxiliary material component; drying: The abrasive component and the auxiliary material component were dried in an oven at 60 °C for 24 h and placed in a constant temperature and humidity environment; (3) Mixing: Phenolic resin liquid was selected as the wetting agent, 3 parts of phenolic resin liquid was weighed, and the phenolic resin liquid was added to the abrasive component and mixed thoroughly for 5 minutes; then the auxiliary material component was added and mixed thoroughly for 5 minutes to prepare a mixed component; Screening: The mixed components are screened with a mesh size of 10 meshes to obtain loose cutting disc components, and after screening, they are left standing in a constant temperature and humidity environment; (4) Pressing: Place a hoop at the bottom of the mold, and place a fiber reinforcement mesh on the hoop; add the cutting disc components according to the required ratio of the cutting disc; rotate and level the cutting disc components; place a fiber reinforcement mesh on the cutting disc components after leveling; compact with a pressure of 7 MPa and hold the pressure for 10 s; place a hoop on the fiber reinforcement mesh; compact for the second time with a pressure of 7 MPa and hold the pressure for 5 s to make a cutting disc forming sample; Hot press sintering: The cutting disc forming sample is hot press sintered at a pressure of 10 MPa and a temperature of 130 °C for 1 h; Hardening: Preheat the muffle furnace to 50 °C, put the cutting disc forming sample into the muffle furnace for high-temperature hardening, and the high-temperature hardening heating curve is: keep the temperature at 50 °C for 2 h, raise the temperature to 100 °C at a heating rate of 50 °C / h, keep the temperature at 100 °C for 1 h, raise the temperature to 130 °C at a heating rate of 30 °C / h, keep the temperature at 130 °C for 2 h, raise the temperature to 185 °C at a heating rate of 27.5 °C / h, keep the temperature at 185 °C for 3 h, and then cool with the furnace to 30 °C to make a low-heat and high-efficiency rail cutting disc, and its physical object is as Figure 1 shown.

[0029] Example 2 This example provides a low-heat and high-efficiency rail cutting disc, and its preparation method is as follows: (1) In this example, the self-lubricating pore-forming filler is made by the method of Example 1; (2) Premix: Weigh 35 parts of brown fused alumina, 75 parts of zirconium corundum, and 10 parts of cubic boron nitride for mixing; the brown fused alumina is selected with a mesh size of 24 meshes, the zirconium corundum is selected with a mesh size of 16 meshes, and the cubic boron nitride is selected with a mesh size of 20 meshes; send the abrasive into a mixer and mix for 5 min to achieve full mixing to obtain mixed abrasive; Weigh 6 parts of self-lubricating pore-forming filler; the carbamide graphite molybdenum disulfide composite filler particles are selected with a mesh size of 24 meshes; add the carbamide graphite molybdenum disulfide composite filler particles to the above-mentioned mixed abrasive and mix well for 3 min to make an abrasive component; Weigh 8 parts of phenolic resin powder, 3 parts of cryolite, 5.5 parts of pyrite, 2 parts of calcium oxide, and 10 parts of precipitated barium sulfate; the phenolic resin powder is selected with a mesh size of 300 meshes and the functional filler has a mesh size of 150 meshes; send the phenolic resin powder and the functional filler into a drum mixer and mix well for 5 h to make an auxiliary material component; Drying: The abrasive component and the auxiliary component are dried in an oven at 60 °C for 24 h and placed in a constant temperature and humidity environment; (3)Mixing: Phenolic resin solution is selected as the wetting agent. Weigh 3 parts of phenolic resin solution, add the phenolic resin solution to the abrasive component, and mix well for 5 min; then add the auxiliary component and mix well for 5 min to make a mixed component; Sieving: The mixed component is sieved with a mesh size of 10 meshes to obtain a loose cutting disc component, and after sieving, it is left standing in a constant temperature and humidity environment; (4)Pressing: Place a hoop at the bottom of the mold, and place a fiber reinforcement mesh on the hoop; add the cutting disc component according to the required proportion of the cutting disc; rotate and level the cutting disc component; place a fiber reinforcement mesh on the cutting disc component after leveling; compact it with a pressure of 7 MPa and hold the pressure for 10 s; place a hoop on the fiber reinforcement mesh; compact it for the second time with a pressure of 7 MPa and hold the pressure for 5 s to make a formed sample of the cutting disc; Hot pressing and sintering: The formed sample of the cutting disc is hot pressed and sintered at a pressure of 10 MPa and a temperature of 130 °C for 1 h; Hardening: Preheat the muffle furnace to 50 °C, place the formed sample of the cutting disc into the muffle furnace for high-temperature hardening. The high-temperature hardening heating rate curve is as follows: keep the temperature at 50 °C for 2 h, raise the temperature to 100 °C at a heating rate of 50 °C / h, keep the temperature at 100 °C for 1 h, raise the temperature to 130 °C at a heating rate of 30 °C / h, keep the temperature at 130 °C for 2 h, raise the temperature to 185 °C at a heating rate of 27.5 °C / h, keep the temperature at 185 °C for 3 h, and then cool it in the furnace to 30 °C to make a low-heat and high-efficiency rail cutting disc.

[0030] Example 3 This example provides a low-heat and high-efficiency rail cutting disc, and its preparation method is as follows: (1)In this example, the self-lubricating pore-forming filler is made by the method of Example 1; (2)Premixing: Weigh 35 parts of brown fused alumina, 75 parts of zirconium corundum, and 10 parts of cubic boron nitride for mixing; the brown fused alumina has a mesh size of 24 meshes, the zirconium corundum has a mesh size of 16 meshes, and the cubic boron nitride has a mesh size of 20 meshes; send the abrasive into a mixer and mix for 5 min to achieve sufficient mixing to obtain a mixed abrasive; Weigh 4 parts of self-lubricating pore-forming filler; the carbamide graphite molybdenum disulfide composite filler particles have a mesh size of 24 meshes; add the carbamide graphite molybdenum disulfide composite filler particles to the above-mentioned mixed abrasive and mix well for 3 min to make an abrasive component; Weigh 8 parts of phenolic resin powder, 3 parts of cryolite, 5.5 parts of pyrite, 2 parts of calcium oxide, and 10 parts of precipitated barium sulfate; the phenolic resin powder has a mesh number of 300, and the functional filler has a mesh number of 150; send the phenolic resin powder and the functional filler into a drum mixer and mix well for 5 h to make the auxiliary component. Drying: The abrasive component and the auxiliary component are dried in an oven at 60 °C for 24 h and placed in a constant temperature and humidity environment. (3) Mixing: Select phenolic resin liquid as the wetting agent, weigh 3 parts of phenolic resin liquid, add the phenolic resin liquid to the abrasive component, and mix well for 5 min; then add the auxiliary component and mix well for 5 min to make the mixed component. Sieving: The mixed component is sieved with a mesh number of 10 to obtain a loose cutting disc component, and after sieving, it is left standing in a constant temperature and humidity environment. (4) Pressing: Place a hoop at the bottom of the mold, and place a fiber reinforced mesh on the hoop; add the cutting disc component according to the required ratio of the cutting disc; rotate and flatten the cutting disc component; after flattening, place a fiber reinforced mesh on the cutting disc component; compact it with a pressure of 7 MPa and hold the pressure for 10 s; place a hoop on the fiber reinforced mesh; compact it for the second time with a pressure of 7 MPa and hold the pressure for 5 s to make the cutting disc forming sample. Hot press sintering: The cutting disc forming sample is hot press sintered at a pressure of 10 MPa and a temperature of 130 °C for 1 h. Hardening: Preheat the muffle furnace to 50 °C, place the cutting disc forming sample in the muffle furnace for high-temperature hardening, and the high-temperature hardening heating curve is: keep the temperature at 50 °C for 2 h, raise the temperature to 100 °C at a heating rate of 50 °C / h, keep the temperature at 100 °C for 1 h, raise the temperature to 130 °C at a heating rate of 30 °C / h, keep the temperature at 130 °C for 2 h, raise the temperature to 185 °C at a heating rate of 27.5 °C / h, keep the temperature at 185 °C for 3 h, and then cool it in the furnace to 30 °C to make a low-heat and high-efficiency rail cutting disc.

[0031] Example 4 The preparation method of the self-lubricating pore-forming filler for the cutting disc in this example is the same as that in Example 1, except that the formula ratio of the cutting disc is different.

[0032] The cutting disc in this example includes: by weight, 40 parts of brown fused alumina, 80 parts of zirconium corundum, 15 parts of cubic boron nitride, 20 parts of phenolic resin powder, 5 parts of phenolic resin liquid, 15 parts of barium sulfate, 5 parts of cryolite, 7 parts of pyrite, 3 parts of calcium oxide, and 8 parts of self-lubricating pore-forming filler.

[0033] Example 5 The preparation method of the self-lubricating pore-forming filler for the cutting disc in this example is the same as that in Example 3, except for the different formulation ratios of the cutting disc.

[0034] The cutting disc of this example includes: by weight, 30 parts of brown fused alumina, 60 parts of zirconium corundum, 10 parts of cubic boron nitride, 10 parts of phenolic resin powder, 3 parts of phenolic resin liquid, 10 parts of barium sulfate, 3 parts of cryolite, 5 parts of pyrite, 2 parts of calcium oxide, and 4 parts of self-lubricating pore-forming filler.

[0035] Comparative Example 1 To test the low-temperature and high-efficiency cutting effect of the low-heat and high-efficiency rail cutting disc for railway rails, this comparative example was set up. The specific preparation method of the comparative sample is as follows: (1) Premix: Weigh 35 parts of brown fused alumina, 75 parts of zirconium corundum, and 10 parts of cubic boron nitride and mix them; the brown fused alumina is selected with a mesh number of 24, the zirconium corundum is selected with a mesh number of 16, and the cubic boron nitride is selected with a mesh number of 20; send the abrasive into a mixer and mix for 5 min to achieve sufficient mixing to obtain the abrasive component; Weigh 8 parts of phenolic resin powder, 3 parts of cryolite, 5.5 parts of pyrite, 2 parts of calcium oxide, and 10 parts of precipitated barium sulfate; the phenolic resin powder is selected with a mesh number of 300 and the functional filler is selected with a mesh number of 150; send the phenolic resin powder and the functional filler into a drum mixer and mix thoroughly for 5 h to make the auxiliary component; (2) Drying: The abrasive component and the auxiliary component are dried in an oven at 60 °C for 24 h and placed in a constant temperature and humidity environment; (3) Mixing: Select phenolic resin liquid as the wetting agent, weigh 3 parts of phenolic resin liquid, add the phenolic resin liquid to the abrasive component and mix thoroughly for 5 min; then add the auxiliary component and mix thoroughly for 5 min to make the mixed component; Sieving: The mixed component is sieved with a mesh number of 10 to obtain a loose cutting disc component, and after sieving, it is left standing in a constant temperature and humidity environment; (4) Pressing: Place a hoop at the bottom of the mold, and place a fiber reinforced mesh on the hoop; add the cutting disc component according to the required ratio of the cutting disc; rotate and flatten the cutting disc component; after flattening, place a fiber reinforced mesh on the cutting disc component; compact it with a pressure of 7 MPa and keep the pressure for 10 s; place a hoop on the fiber reinforced mesh; compact it for the second time with a pressure of 7 MPa and keep the pressure for 5 s to make the cutting disc forming sample; Hot press sintering: The cutting disc forming sample is hot press sintered at a pressure of 10 MPa and a temperature of 130 °C for 1 h; Hardening: Preheat the muffle furnace to 50 °C, put the formed sample of the cutting disc into the muffle furnace for high-temperature hardening. The high-temperature hardening heating curve is as follows: keep the temperature at 50 °C for 2 h, then raise the temperature to 100 °C at a heating rate of 50 °C / h, keep the temperature at 100 °C for 1 h, then raise the temperature to 130 °C at a heating rate of 30 °C / h, keep the temperature at 130 °C for 2 h, then raise the temperature to 185 °C at a heating rate of 27.5 °C / h, keep the temperature at 185 °C for 3 h, and then cool it in the furnace to 30 °C to make the rail cutting disc.

[0036] Use a rail cutting machine to test the cutting performance of the low-heat and high-efficiency rail cutting disc for railway rails in the embodiment. The cutting piece is a 60-rail, and the material of the 60-rail is U71Mn rail steel; the cutting test starts from the contact between the cutting disc and the 60-rail and ends when the 60-rail is completely separated. Count the number of times the cutting disc cuts in, the cutting time, the cutting loss, the perpendicularity, parallelism, flatness of the cross-section of the 60-rail after cutting, and the burning situation of the rail after cutting.

[0037] The number of times of cutting in refers to the number of times the cutting disc contacts the 60-rail during the cutting process; the cutting time is the time consumed from the contact between the cutting disc and the 60-rail to the complete cutting and separation of the 60-rail; the cutting loss refers to the reduction in the radius of the cutting disc after one rail cutting.

[0038] The comparison of the loss before and after one cut of Example 1 is as Figure 2 shown; the burning situation of the rail cutting surface after one cut of Example 1 and Comparative Example 1 is as Figure 3 shown; the perpendicularity of the rail cutting surface after one cut of Example 1 and Comparative Example 1 is as Figure 4 shown; the parallelism of the rail cutting surface after one cut of Example 1 and Comparative Example 1 is as Figure 5 shown; the flatness of the rail cutting surface after one cut of Example 1 and Comparative Example 1 is as Figure 6 shown.

[0039] In actual construction operations, the number of times of cutting in is the main measurement index for on-site testing. Usually, the rail cutting is completed with 1 - 2 cuts, and preferably 1 cut, to reduce the processing error caused by repeated cutting and affect the final overall processing quality; therefore, achieving 1 cut indicates that the cutting disc has good cutting performance, which is the main factor valued in on-site processing.

[0040] From Figure 2 it can be seen that the cutting loss of Example 1 after single cutting is 10 mm; from Figure 3It can be seen that Example 1 can achieve one - cut cutting. After single - cut, the cutting surface is bright, flat, with clear texture and no obvious burn marks. In the comparative example, obvious burning occurs on the cutting surface after single - cut; from Figure 4 and Figure 5 and Figure 6 it can be seen that after cutting in Example 1, the parallelism, perpendicularity and flatness all meet the tolerance requirements for rail cutting and processing. After cutting in Comparative Example 1, the maximum tolerance requirements for rail cutting and processing are not met.

[0041] Under the same test conditions, the test results of Examples 1 - 3 and Comparative Example 1 are statistically shown in Table 1.

[0042] Table 1: Cutting performance test results of Examples 1 - 3 and Comparative Example 1

[0043] In the table, "-" represents no data satisfying the parallelism test.

[0044] It can be seen from Table 1 the cutting performance of Examples 1 - 3 and Comparative Example 1 after single - cut. Examples 1 - 3 can complete the cutting of the 60 - rail cross - section within 1 cut. And compared with Comparative Example 1, with the increase of the content of the self - lubricating pore - forming material, the cutting time is shortened, the cutting loss increases, and the perpendicularity, parallelism and flatness quality of the 60 - rail cross - section after cutting are improved.

[0045] In the present invention, carbamide graphite molybdenum disulfide composite filler particles are added to the traditional cutting - disc material. Pores are formed through the decomposition of the pore - forming material components. The pore structure of the cutting disc can effectively accommodate the chips generated at the cutting - disc / rail contact interface as a high - temperature heat source, and under the action of the centrifugal force of the cutting disc after separating from the contact interface, the chips, the high - temperature heat source, are discharged in time. At the same time, the pores can effectively increase the protrusion height of the abrasives in the cutting disc, improving the cutting performance of the abrasives. And the solid lubricant material of the cutting disc is released through the pore structure on the cutting - disc / rail contact surface, acting on the abrasives and the rail surface, and can realize the lubrication effect at the contact interface between the abrasives and the material, reducing frictional heat generation. The low - heat and high - efficiency rail cutting disc realizes the function of low heat generation through two ways: timely accommodating and discharging the high - temperature heat source (abrasive chips) and reducing the heat generation at the source (frictional heat generation).

[0046] In summary, the low - heat and high - efficiency rail cutting disc for railway rail cutting obtained by the preparation method of the present invention has good cutting performance, greatly shortens the cutting time, reduces rail burning, meets the tolerance range required for rail cutting and processing, and can realize low - heat - generation and high - efficiency rail cutting.

[0047] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative efforts. Therefore, all technical solutions that can be obtained by those skilled in the art in this technical field based on the concept of the present invention through logical analysis, reasoning, or limited experiments on the basis of the prior art should fall within the protection scope determined by the claims.

Claims

1. A low-heat and high-efficiency rail cutting blade, characterized in that: The raw materials include, by weight: 100-135 parts of abrasive, 10-20 parts of resin adhesive, 20-30 parts of functional filler, 4-8 parts of self-lubricating pore-forming material, and 3-5 parts of wetting agent.

2. The low heat and high efficiency rail cutting blade according to claim 1, characterized in that: The abrasive comprises 30-40 parts of brown corundum, 60-80 parts of zirconium corundum and 10-15 parts of cubic boron nitride.

3. The low heat and high efficiency rail cutting blade according to claim 1, characterized in that: The resin adhesive includes phenolic resin powder.

4. The low heat and high efficiency rail cutting blade according to claim 1, characterized in that: The functional filler comprises 10-15 parts of precipitated barium sulfate, 3-5 parts of cryolite, 5-7 parts of pyrite powder and 2-3 parts of calcium oxide.

5. The low heat and high efficiency rail cutting blade according to claim 1, characterized in that: The self-lubricating pore-forming material is carbonamide graphite molybdenum disulfide composite filler particles; Its components include a pore-forming component and a self-lubricating component; wherein the pore-forming component is carbonamide, and the self-lubricating component is flaky graphite powder and molybdenum disulfide powder.

6. The low-heat and high-efficiency rail cutting blade according to claim 5, characterized in that: The preparation method of the carbonamide graphite molybdenum disulfide composite filler particles comprises the following steps: The molten carbamide is mixed with flaky graphite powder and molybdenum disulfide powder to complete the attachment and wrapping of the flaky graphite powder and the molybdenum disulfide powder. After cooling and forming, the carbamide graphite molybdenum disulfide composite filler particles are obtained by crushing and sieving.

7. The low-heat and high-efficiency rail cutting blade according to claim 5, characterized in that: In the carbonamide graphite molybdenum disulfide composite filler particles, the proportions of the components are 30-40 parts of carbonamide, 6-9 parts of graphite powder, and 4-6 parts of molybdenum disulfide powder, calculated by mass.

8. The low heat and high efficiency rail cutting blade according to claim 1, characterized in that: The wetting agent includes a phenolic resin solution.

9. The low heat and high efficiency rail cutting blade according to claim 1, characterized in that: The particle size of the resin adhesive is 280-350 meshes, the particle size of the abrasive is 16-24 meshes, the particle size of the self-lubricating pore-forming filler is 24-30 meshes, and the particle size of the functional filler is 100-150 meshes.

10. A method for preparing a low-heat and high-efficiency rail cutting blade according to any one of claims 1 to 9, characterized in that: The steps include: (1) Weighing the raw materials in proportion, mixing brown corundum, zirconium corundum and cubic boron nitride to obtain a mixed abrasive; adding a self-lubricating pore-forming filler to the mixed abrasive to obtain an abrasive component; mixing a resin adhesive with a functional filler to obtain an auxiliary material component; drying the abrasive component and the auxiliary material component and placing them in a constant temperature and humidity environment; (2) adding a wetting agent to the abrasive component and mixing them, and then adding the auxiliary material component and mixing them to form a mixed component; the mixed component is sieved to obtain a loose cutting piece component, and after sieving, it is left to stand in a constant temperature and humidity environment; (3) The cutting blade components and the fiber reinforced mesh are pressed to form a cutting blade molded sample; the cutting blade molded sample is subjected to hot pressing, sintering, and hardening to obtain a low-heat and high-efficiency rail cutting blade.

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