Wear-resistant lining plate and preparation process therefor

Abstract

A wear-resistant lining plate, comprising a wear-resistant lining plate body (1). The wear-resistant lining plate body (1) consists of a 42CrMo base material (2) and a thermally sprayed NiCr alloy coating (3), wherein the thermally sprayed NiCr alloy coating (3) is sprayed on the surface of the wear-resistant lining plate body (1) in contact with waste edge materials and the outer circle of the wear-resistant lining plate body. The preparation process for the wear-resistant lining plate comprises the following steps: feeding, workpiece forging, rough machining, tempering, surface pre-machining, workpiece surface purification, drying, surface roughening, fitting between workpiece and tooling, spraying a NiCr powder alloy, heat treatment, treatment after spraying, and mounting a waste edge coiler for normal operation.

Description

A wear-resistant lining and its preparation process Technical Field

[0001] The invention belongs to the technical field of wear-resistant lining plates, and in particular relates to a wear-resistant lining plate and a preparation process thereof. Background Art

[0002] A conventional scrap coiler consists of a tapered shaft, two vertical plates, a power unit, two retaining rings, and two wear-resistant liners. The large end of the tapered shaft passes through the vertical plate on the same side and connects to the power unit. The two retaining rings are mounted on the two vertical plates, mounted on the shaft sleeves and rotating with the shaft. The two wear-resistant liners are mounted on each end of the tapered shaft. The right spray-coated wear-resistant liner is mounted on the large end of the tapered shaft, and the left spray-coated wear-resistant liner is mounted on the small end of the tapered shaft. The wear-resistant liners are a detachable modular structure, facilitating maintenance and replacement of spare parts.

[0003] In the early design of wear-resistant linings, 45 steel was selected as the material. After a period of operation, scratches and wear appeared on the contact surface between the wear-resistant lining and the waste material, and the depth of local wear reached 2-3mm. In addition, the outer circle of the wear-resistant lining was also scratched due to the involvement of a small amount of waste edge. This not only affected the appearance of the equipment, but also brought certain risks to production safety. Conventional waste edge coilers had to be disassembled for maintenance or replacement of spare parts after 2-3 months of operation, resulting in increased costs. To this end, the present invention designs a wear-resistant lining that can extend the service life of the wear-resistant lining, effectively improve friction and rigidity, and reduce deformation.

[0004] Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a wear-resistant lining and a preparation process thereof, which can increase the service life of the wear-resistant lining, effectively improve friction and rigidity, and reduce deformation.

[0006] In order to achieve the above functions, the technical solution adopted by the present invention is as follows: a wear-resistant liner includes a wear-resistant liner body, the wear-resistant liner body is composed of a 42CrMo substrate and a sprayed NiCr alloy coating, the sprayed NiCr alloy coating is sprayed on the contact surface and outer circle of the wear-resistant liner body and the scrap material, the sprayed NiCr alloy coating has a thickness of 0.7-0.8mm and a hardness of HV=1200-1300.

[0007] As a preferred technical solution of the present invention, countersunk holes are evenly arranged on the wear-resistant liner body, and the countersunk holes are arranged in a circular array.

[0008] The present invention also discloses a preparation process of a wear-resistant liner, comprising the following steps:

[0009] (1) Prepare the raw material 42CrMo, casting mold and various processing equipment, transport the raw material to the melting furnace, pour the smelted raw material solution into the casting mold, cool the casting mold after casting to obtain the blank, and clean the casting mold and casting;

[0010] (2) After the blank is cooled, it is placed on the forging equipment for forging and pressing;

[0011] (3) According to the required liner shape and size, the blank is rough-processed by mechanical processing, and the blank is cut into a predetermined shape to obtain a 42CrMo base material;

[0012] (4) placing the 42CrMo substrate into a furnace and performing heat treatment according to a specific heating process curve;

[0013] (5) Pre-processing the surface of 42CrMo substrate, and reserve a certain thickness of spray coating on the substrate;

[0014] (6) Clean the 42CrMo substrate as a whole, and thoroughly remove the oil, paint, oxides, etc. attached to the surface of the 42CrMo substrate to reveal a fresh metal surface;

[0015] (7) Remove moisture from the surface of 42CrMo substrate to ensure that the workpiece is dry and clean;

[0016] (8) Surface roughening of 42CrMo substrate;

[0017] (9) After the 42CrMo substrate is assembled with the tooling, a NiCr alloy coating with a thickness of 0.7-0.8 mm is sprayed on the liner using a supersonic spraying device to obtain a liner;

[0018] (10) heat treating the liner at a temperature of 980-1080°C to fuse the sprayed NiCr alloy coating with the 42CrMo substrate;

[0019] (11) After spraying, the gaps in the coating are sealed to improve the performance of the surface;

[0020] (12) Install the scrap coiler and ensure it operates normally.

[0021] As a preferred technical solution of the present invention, the surface roughening method in step (eight) is sandblasting the workpiece surface, and the material used is corundum sand Al2O3 or quartz sand (SiO2).

[0022] As a preferred technical solution of the present invention, the spraying process from the spraying material entering the heat source to forming the sprayed NiCr alloy coating in step (9) generally goes through four stages, and the specific steps are as follows:

[0023] (1) Heating and melting of spraying materials: NiCr alloy powder enters the high temperature area of ​​the heat source and is heated, melted or softened during the process;

[0024] (2) The melted spray material is atomized: under the action of the external compressed air flow or the jet of the heat source itself, it is pushed forward by the air flow into the heat source jet;

[0025] (3) Jet flight of molten or softened fine particles: During the flight, the particles are first accelerated to form a particle stream. As the flight distance increases, the particle speed gradually decreases.

[0026] (4) Particles collide, deform, solidify and accumulate on the surface of the 42CrMo substrate: When fine particles with a certain temperature and speed come into contact with the substrate surface, the particles collide strongly with the substrate surface, and the kinetic energy of the particles is converted into heat energy and partially transferred to the 42CrMo substrate. At the same time, the fine particles deform along the uneven surface. The deformed particles quickly condense and shrink, and flatten and adhere to the surface of the substrate. The sprayed particle beam still needs to move continuously and impact the surface, resulting in a collision-deformation-condensation and shrinkage process. The deformed particles and the surface of the 42CrMo substrate, as well as the particles themselves, adhere to each other, thereby forming a sprayed NiCr alloy coating.

[0027] Compared with the prior art, the wear-resistant liner and its preparation process of the present invention have the following advantages: 42CrMo is used instead of 45 steel to make the wear-resistant liner, which improves its hardenability and corrosion resistance, and improves the strength, elastic limit and yield limit of the steel, and maintains sufficient strength and creep resistance at high temperatures. It is made using advanced equipment and processes, and is supersonic flame sprayed with NiCr alloy powder with a spray speed of 1200m / s. The hardness of the sprayed layer reaches HV1200-HV1300, forming a heat-resistant and corrosion-resistant melt-sprayed NiCr alloy coating to protect the metal surface of the wear-resistant liner. After one-time operation, the service life of the entire waste edge coiler can reach 9-10 months, reducing manpower, reducing the disassembly and replacement of spare parts, improving production efficiency, and also reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG1 is a side sectional view of a wear-resistant liner body of a wear-resistant liner of the present invention;

[0029] FIG2 is a top view of a wear-resistant liner body of a wear-resistant liner of the present invention;

[0030] FIG3 is a flow chart of a preparation process of a wear-resistant liner according to the invention.

[0031] Among them, 1. Wear-resistant liner body, 2. 42CrMo base material, 3. Sprayed NiCr alloy coating, 4. Countersink. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be described clearly and completely below. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] The present invention provides a wear-resistant liner, comprising a wear-resistant liner body 1, wherein the wear-resistant liner body 1 is composed of a 42CrMo substrate 2 and a sprayed NiCr alloy coating 3, wherein the sprayed NiCr alloy coating 3 is sprayed on the contact surface between the wear-resistant liner body 1 and the scrap material and on the outer circle, wherein the sprayed NiCr alloy coating 3 has a thickness of 0.7-0.8 mm and a hardness of HV=1200-1300, and countersunk holes 4 are evenly arranged on the wear-resistant liner body 1, and the countersunk holes 4 are arranged in a circular array.

[0034] The present invention also discloses a preparation process of a wear-resistant liner, comprising the following steps:

[0035] (1) Prepare the raw material 42CrMo, casting mold and various processing equipment, transport the raw material to the melting furnace, pour the smelted raw material solution into the casting mold, cool the casting mold after casting to obtain the blank, and clean the casting mold and casting;

[0036] (2) After the blank is cooled, it is placed on the forging equipment for forging and pressing;

[0037] (3) According to the required liner shape and size, the blank is rough-processed by mechanical processing, and the blank is cut into a predetermined shape to obtain a 42CrMo base material;

[0038] (4) placing the 42CrMo substrate into a furnace and performing heat treatment according to a specific heating process curve;

[0039] (5) Pre-processing the surface of 42CrMo substrate, and reserve a certain thickness of spray coating on the substrate;

[0040] (6) Clean the 42CrMo substrate as a whole, and thoroughly remove the oil, paint, oxides, etc. attached to the surface of the 42CrMo substrate to reveal a fresh metal surface;

[0041] (7) Remove moisture from the surface of 42CrMo substrate to ensure that the workpiece is dry and clean;

[0042] (8) Surface roughening of 42CrMo substrate, the surface roughening method is sandblasting the workpiece surface, and the material is corundum sand Al2O3 or quartz sand (SiO2);

[0043] (9) After the 42CrMo substrate is assembled with the tooling, a NiCr alloy coating with a thickness of 0.7-0.8 mm is sprayed on the liner using a supersonic spraying device to obtain a liner;

[0044] (10) heat treating the liner at a temperature of 980-1080°C to fuse the sprayed NiCr alloy coating with the 42CrMo substrate;

[0045] (11) After spraying, the gaps in the coating are sealed to improve the performance of the surface;

[0046] (12) Install the scrap coiler and ensure it operates normally.

[0047] The spraying process from the spraying material entering the heat source to the formation of the sprayed NiCr alloy coating in step (9) generally goes through four stages, and the specific steps are as follows:

[0048] (1) Heating and melting of spraying materials: NiCr alloy powder enters the high temperature area of ​​the heat source and is heated, melted or softened during the process;

[0049] (2) The melted spray material is atomized: under the action of the external compressed air flow or the jet of the heat source itself, it is pushed forward by the air flow into the heat source jet;

[0050] (3) Jet flight of molten or softened fine particles: During the flight, the particles are first accelerated to form a particle stream. As the flight distance increases, the particle speed gradually decreases.

[0051] (4) Particles collide, deform, solidify and accumulate on the surface of the 42CrMo substrate: When fine particles with a certain temperature and speed come into contact with the substrate surface, the particles collide strongly with the substrate surface, and the kinetic energy of the particles is converted into heat energy and partially transferred to the 42CrMo substrate. At the same time, the fine particles deform along the uneven surface. The deformed particles quickly condense and shrink, and flatten and adhere to the surface of the substrate. The sprayed particle beam still needs to move continuously and impact the surface, resulting in a collision-deformation-condensation and shrinkage process. The deformed particles and the surface of the 42CrMo substrate, as well as the particles themselves, adhere to each other, thereby forming a sprayed NiCr alloy coating.

[0052] Table 1 Comparison of material composition of 42CrMo and 45 steel

[0053] Comparing the above ingredients:

[0054] (1) In the composition of 42CrMo, the Cr content is 0.90-1.20%, which is much greater than the Cr content of 45 steel (≤0.25%). The role of Cr in steel is mainly to improve its hardenability and corrosion resistance, and to increase the strength, elastic limit and yield limit of steel.

[0055] (2) In the composition of 42CrMo, Mo: 0.15~0.25%, while 45 steel does not have this component; the role of Mo in steel: Mo refines the grain of steel, improves hardenability and heat resistance, and maintains sufficient strength and creep resistance at high temperatures;

[0056] (3) In the composition of 42CrMo steel, the impurity S component is strictly controlled, and the residual content is allowed to be ≤0.035%.

[0057] In summary, 45 steel is a high-quality carbon structural steel with low hardness and easy cutting; while 42CrMo is an ultra-high strength steel. Because its composition contains chromium Cr: 0.90~1.20%, Ni content ≤0.30%, molybdenum Mo: 0.15~0.25%, etc., it has high strength and toughness, good hardenability, no obvious temper brittleness, small deformation during quenching, high fatigue limit and resistance to multiple impacts after quenching and tempering treatment, good low-temperature impact toughness, and high creep strength and endurance strength at high temperatures.

[0058] Table 2 Comparison of mechanical properties of 42CrMo and 45 steel (sample size is 25mm)

[0059] In summary, 42CrMo has high strength, high hardenability, good toughness, small deformation during quenching, and high creep resistance and endurance strength during operation or at high temperatures.

[0060] The present invention and its embodiments are described above. Such description is not restrictive. The embodiment shown in the embodiment is only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if a person skilled in the art is inspired by the above, and does not deviate from the purpose of the invention, without creatively designing a structure and embodiment similar to the technical solution, they shall fall within the scope of protection of the present invention.

Claims

1. A wear-resistant lining plate, characterized in that, It includes a wear-resistant lining plate body (1), and the wear-resistant lining plate body (1) is composed of a 42CrMo base material (2) and a sprayed NiCr alloy coating (3). The sprayed NiCr alloy coating (3) is sprayed on the contact surface between the wear-resistant lining plate body (1) and the waste edge material and the outer circle. The thickness of the sprayed NiCr alloy coating (3) is 0.7 - 0.8 mm and the hardness HV = 1200 - 1300.

2. The wear-resistant lining plate according to claim 1, characterized in that, Counterbores (4) are uniformly arranged on the wear-resistant lining plate body (1), and the counterbores (4) are arranged in a circular array.

3. The preparation process of a wear-resistant lining plate according to any one of claims 1 to 2, characterized in that, It includes the following steps: (1) Prepare raw materials 42CrMo, casting molds, and various processing equipment, convey and feed them into a melting furnace. Pour the melted raw material solution into the casting molds. After casting, cool the casting molds, obtain blanks, and clean the casting molds and the castings; (2) Place the cooled blanks on forging equipment for forging and pressing; (3) According to the required shape and size of the lining plate, perform rough machining on the blank parts by mechanical processing, cut the blank parts into a predetermined shape, and obtain the 42CrMo base material; (4) Put the 42CrMo base material into a furnace and perform heat treatment according to a specific heating process curve; (5) Pre-process the surface of the 42CrMo base material, and reserve a certain thickness of the sprayed coating on the base material; (6) Clean the entire 42CrMo base material, thoroughly remove the oil stains, paints, oxides, etc. attached to the surface of the 42CrMo base material, and expose a fresh metal surface; (7) Remove the moisture on the surface of the 42CrMo base material to ensure that the workpiece is dry and clean; (8) Roughen the surface of the 42CrMo base material; (9) After the 42CrMo base material is clamped with the tooling, use a supersonic spraying device to spray a sprayed NiCr alloy coating on the lining plate with a thickness of 0.7 - 0.8 mm to obtain the lining plate; (10) Perform heat treatment on the lining plate at a temperature of 980 - 1080 °C to make the sprayed NiCr alloy coating and the 42CrMo base material integrate; (11) Close the voids of the coating after spraying to improve the surface performance; (12) Install a waste edge coiler and operate it normally.

4. The preparation process of a wear-resistant lining plate according to claim 3, characterized in that, The surface roughening method in step (8) is to sandblast the surface of the workpiece, and the materials used are corundum sand Al2O3 or quartz sand (SiO2).

5. The preparation process of a wear-resistant lining plate according to claim 3, characterized in that, When the spraying material enters the heat source to form the sprayed NiCr alloy coating in step (9), the spraying process generally goes through four stages, and the specific steps are as follows: (1) Heating and melting of the spraying material: The NiCr alloy powder enters the high-temperature area of the heat source and is heated and melted or softened during the traveling process; (2) Atomization of the melted spraying material: Under the action of an externally applied compressed air flow or the jet flow of the heat source itself, it is pushed forward by the air flow or the heat source jet flow; (3) Jet flight of the molten or softened fine particles: During the flight process, the particles are first accelerated to form a particle stream, and as the flight distance increases, the particle movement speed gradually decreases; (4) Particles collide, deform, solidify and accumulate on the surface of the 42CrMo substrate: When fine particles with a certain temperature and velocity contact the substrate surface, strong collisions occur between the particles and the substrate surface. The kinetic energy of the particles is converted into heat energy and partially transferred to the 42CrMo substrate. At the same time, the fine particles deform along the uneven surface. The deformed particles quickly condense and shrink, and adhere flatly to the substrate surface. The sprayed particle beam still needs to continuously move and impact the surface, generating a process of collision - deformation - condensation and shrinkage. The deformed particles bond to each other between the 42CrMo substrate surface and between the particles, thus forming a sprayed NiCr alloy coating.

Images