Method and apparatus for repairing damage to mounting surface of axle housing

Abstract

The present application discloses a method and an apparatus for repairing damage to the mounting surface of a shaft housing. The method includes: obtaining measurement results of the dimensions of corrosion pits at the damaged position of the mounting surface of the shaft housing to determine a defect area at the damaged position, and removing the corrosion layer of the defect area by a machining process; classifying the defect areas, and performing corresponding spraying processes on the defect areas respectively based on the type of each defect area to obtain corresponding repair areas; and performing removal and remanufacturing on each repair area to restore the dimensions of the mounting surface. According to this method, not only can the corrosion products on the mounting surface of the shaft housing be removed, but also after removing the corrosion products by machining, additional treatment and removal treatment are sequentially performed, so that the dimensions of the shaft housing can be efficiently and accurately restored, eliminating the influence on the tissue state, dimensional accuracy, and mechanical performance of parts by conventional thermal repair means, and further extending the service life of the shaft housing.

Description

Cross-reference

[0001] This application claims priority to a Chinese patent application filed on November 30, 2022, with application number 202211529888.9 and invention title "Method for Improving the Bonding Strength of High-Pressure Cold Spray Coating of Aluminum Alloy Parts", and a Chinese patent application filed on October 12, 2022, with application number 202211248277.7 and invention title "Method and Apparatus for Repairing Damage to the Mounting Surface of a Bearing Housing", and incorporates all of their contents by reference into this application.

Technical Field

[0002] This application relates to the technical field of railway transportation, and in particular, to a method and apparatus for repairing damage to the mounting surface of a bearing housing, and a method for improving the bonding strength of a high-pressure cold spray coating of an aluminum alloy part.

Background Art

[0003] Aluminum alloy materials are widely used in fields such as transportation, vehicle manufacturing, and aerospace due to their high specific strength, high specific modulus of elasticity, and good corrosion resistance, and are important materials for the lightweighting of high-speed railways, automobiles, and airplanes. The bearing housing is an important component of railway vehicles such as high-speed trains, urban railways, and subways, and is usually made of high-strength aluminum alloy. In order to prevent galvanic corrosion from occurring on the connection contact surface between the bearing housing and other parts, usually, zinc phosphate varnish is sprayed on this surface for protection. However, during the operation of the vehicle, due to fretting wear and the influence of environmental factors, the zinc phosphate varnish is easily damaged and the substrate is exposed, so galvanic corrosion occurs on the mounting surface of the bearing housing, and various corrosion pits are formed on its surface. As a result, the material of the mounting surface of the aluminum alloy bearing housing is lost, the roughness of the mounting surface exceeds the allowable value and cannot meet the use requirements, and the rejection rate of the parts increases.

[0004] To address such problems, currently, the main approach is to remove the corrosion layer caused by galvanic corrosion on the mounting surface of the axle housing through machining to solve the problem of roughness mismatch. However, the dimensions of the mounting surface of the axle housing reach the lower limit after one or two machining operations. If rust occurs again, it cannot be repaired by machining means and can only be discarded or sealed. Such operations have the problems of high maintenance costs and serious waste of resources. However, in the repair and remanufacturing technologies of materials using high-energy beams such as general lasers, plasmas, and arcs, when repairing 7000-series high-strength aluminum alloys, there are a series of problems that are difficult to overcome conventionally, such as the workpiece being prone to cracking, the heat-affected zone being large, and the hardness of the repair layer being low. Due to the limitations of the processing characteristics of high-strength aluminum alloys, when using arc welding or high-energy laser welding technology for repair, damage to the base material structure of the aluminum alloy cannot be avoided, the mechanical properties of the repaired area deteriorate, precision parts are deformed by the heat input, and the accuracy decreases.

[0005] Currently, cold spray technology is used to perform remanufacturing repair on the corroded surface of the axle housing. However, the bonding strength of general high-pressure cold spray coatings is low, and the bonding strength of the coating can usually only reach 44 - 60 MPa, so it cannot meet the usage requirements of high-standard parts of EMUs (the bonding strength of the coating after repair needs to reach more than 100 MPa).

[0006] As described above, the development of new repair technologies and the repair processes to support them has become an urgent task. Summary of the Invention

[0007] This application provides a method and device for repairing damage to the mounting surface of the axle housing, which can realize the removal of the corroded surface from the mounting surface of the axle housing, efficiently remove the corrosion products while restoring the dimensions of the axle housing, eliminate the influence on the tissue state, dimensional accuracy, and mechanical properties of parts by conventional thermal repair means, and further improve the service life of the axle housing.

[0008] This application provides a method for repairing damage to the mounting surface of a shaft housing, obtaining measurement results of the dimensions of corrosion pits at the damaged position of the mounting surface of the shaft housing, determining the defect area at the damaged position, and removing the corrosion layer of the defect area by machining; classifying the defect areas, and performing corresponding spraying treatments on the defect areas respectively based on the type of each defect area to obtain corresponding repair areas; performing removal and remanufacturing on each repair area to restore the dimensions of the mounting surface and including.

[0009] According to the method for repairing damage to the mounting surface of a shaft housing provided by this application, the step of obtaining measurement results of the dimensions of corrosion pits at the damaged position of the mounting surface of the shaft housing, determining the defect area at the damaged position, and removing the corrosion layer of the defect area by machining is a step of determining each defect area at the damaged position based on the position of the corrosion pits, and each defect area contains at least one of the corrosion pits; obtaining the maximum depth of the corrosion pits in the same defect area and the area of the corresponding defect area to determine the machining range; and removing the corrosion layer of each defect area by the machining within each machining range. and further including.

[0010] According to the method for repairing damage to the mounting surface of a shaft housing provided by this application, the step of obtaining the maximum depth of the corrosion pits in the same defect area and the area of the corresponding defect area to determine the machining range is selecting a plurality of the corrosion pits in the same defect area, measuring the depth of each selected corrosion pit with a depth measuring instrument, and obtaining the maximum depth of the corrosion pits by comparison; measuring the area of the defect area; Determining the processing range of the machining based on the maximum depth of the corrosion pit and the area of the defect region further comprising wherein the area of the processing range of the machining is larger than the area of the defect region, and the depth of the processing range of the machining is not less than the maximum depth of the corrosion pit.

[0011] According to the method for repairing the damage of the mounting surface of the axle housing provided by the present application, within each of the above-mentioned machining processing ranges, after the step of removing the corrosion layer of each defect region by the removal machining process, further comprising the step of performing a fillet transition process on the defect region after the removal machining process, wherein the included angle between the fillet of the defect region after the fillet transition process and the base surface is 30° or less.

[0012] According to the method for repairing the damage of the mounting surface of the axle housing provided by the present application, the step of classifying the defect regions and performing corresponding spraying processes on the defect regions respectively based on the types of the defect regions to obtain corresponding repair regions is obtaining the length and width of each corrosion pit in the defect region, classifying the defect regions based on the length and width of each corrosion pit to determine the types of the defect regions, wherein the types of the defect regions include dot-like defects, linear defects and planar defects, for the dot-like defects, driving a spray gun to spray perpendicularly to the center of the defect region, for the linear defects, driving the spray gun to move along the longitudinal direction of the defect region and ensuring that the moving path does not change in the width direction, and further determining the number of reciprocations of the spray gun based on the maximum depth of the corrosion pit, for the planar defects, driving the spray gun to move along the longitudinal direction and the width direction of the defect region respectively, and further determining the number of reciprocations of the spray gun based on the maximum depth of the corrosion pit further includes.

[0013] According to the method for repairing the damage on the mounting surface of the axle box body provided by this application, for the punctiform defect, both the length and width of the corrosion pit are less than 5 mm; for the linear defect, the length of the corrosion pit is 5 mm or more and the width is 5 mm or less; and all the remaining defects excluding the punctiform defect and the linear defect are the planar defects.

[0014] According to the method for repairing the damage on the mounting surface of the axle box body provided by this application, before the step of obtaining the measurement results of the dimensions of the corrosion pits at the damage position on the mounting surface of the axle box body, determining the defect area at the damage position, and removing the corrosion layer of the defect area by machining, the step of laser cleaning the damage position on the mounting surface; and the step of surface cleaning the damage position after cleaning to expose the corrosion pits at the damage position further includes.

[0015] According to the method for repairing the damage on the mounting surface of the axle box body provided by this application, the step of laser cleaning the damage position on the mounting surface and surface cleaning the damage position after cleaning to expose the corrosion pits at the damage position includes: the step of laser cleaning the damage position on the mounting surface by a laser cleaning system, where the laser power of the laser cleaning system is 50 W to 120 W and the cleaning time is 2 min to 5 min; the step of surface cleaning the damage position after cleaning by a high-pressure air gun to expose the corrosion pits at the damage position further includes.

[0016] According to the method for repairing the damage on the mounting surface of the axle box body provided by this application, before the step of classifying the defect areas and performing corresponding spraying treatments on the defect areas respectively based on the type of each defect area to obtain corresponding repair areas, the step of plugging all the hole-shaped parts in the defect area after machining with plugs sandblasting the defective area after the removal process; preheating and spraying the defective area after sandblasting; and further includes.

[0017] According to the method for repairing the damaged mounting surface of the axle housing provided by the present application, the surface roughness Ra of the defective area after sandblasting is 5.0 μm to 7.6 μm.

[0018] According to the method for repairing the damaged mounting surface of the axle housing provided by the present application, the process parameters of the preheating spray are as follows: using aluminum alloy powder for preheating spray, the particle size of the powder is 10 μm to 60 μm, the drying temperature of the powder is 70 ± 5 °C, the time of the preheating spray is 40 min to 60 min, the spray gas used for the preheating spray is 99.99% nitrogen gas, the gas pressure of the spray gas is 3.5 MPa to 5.5 MPa, the spray distance of the preheating spray is 5 mm to 20 mm, the angle between the spray gun and the spray surface of the preheating spray is 60° or more including this.

[0019] The present application further provides a device for repairing the damaged mounting surface of the axle housing, which can execute the method for repairing the damaged mounting surface of the axle housing as described above.

[0020] The device for repairing the damaged mounting surface of the axle housing includes: a dimension measurement system for obtaining the measurement result of the dimensions of the corrosion pits at the damaged position of the mounting surface of the axle housing; a removal processing system for determining the defective area at the damaged position based on the measurement result of the dimensions of the corrosion pits and removing the corrosion layer of the defective area by removal processing; A spraying system for classifying the defect areas and performing corresponding spraying processes on each of the defect areas based on the type of each defect area to obtain corresponding repair areas, and a removal and remanufacturing system for performing removal and remanufacturing on each of the repair areas to restore the dimensions of the mounting surface are included.

[0021] The present application further provides an aluminum alloy powder used in a method for repairing damage to the mounting surface of the above-mentioned axle housing. The aluminum alloy powder contains, by weight percentage, 3.2 to 7.8% of Zn, 2.0 to 2.7% of Mg, 1.5 to 2.9% of Cu, 0.02 to 0.06% of Ti, 0.3 to 1.5% of C, 0.05 to 0.20% of Zr, 1.0% to 2.8% of Nd, 0.01 to 0.08% of Sr, and the balance is Al.

[0022] According to an embodiment of the present application, the aluminum alloy powder contains, by weight percentage, 1.2 to 2.5% of Nd and / or 0.02 to 0.06% of Sr. Through research, it has been found that when the Nd element and the Sr element are within the range of the content, the bonding strength of the coating can be improved and the porosity can be reduced.

[0023] In some specific examples, it contains 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0%, 2.1%, 2.2%, 2.3%, 2.4% or 2.5% of Nd.

[0024] In some specific examples, it contains 0.02%, 0.03%, 0.04%, 0.05% or 0.06% of Sr.

[0025] According to an embodiment of the present application, the aluminum alloy powder contains, by weight percentage, 2.2 to 2.3% of Mg, 5.3 to 6.5% of Zn, 1.2 to 2.5% of Nd, 0.9 to 1.0% of C, 0.12 to 0.15% of Zr, 2.0 to 2.2% of Cu, 0.03 to 0.04% of Ti, 0.02 to 0.06% of Sr, and the balance is Al.

[0026] According to the embodiments of the present application, the aluminum alloy powder contains, by weight percentage, 5.3% Zn, 2.3% Mg, 2.2% Cu, 0.04% Ti, 0.9% C, 0.12% Zr, 1.9% Nd, 0.04% Sr, and the balance is Al.

[0027] According to the embodiments of the present application, the particle size of the aluminum alloy powder is 10 μm to 60 μm. Usually, the powder can be screened using a sieve. Through research, it has been found that the powder within this particle size range is more uniform and has good fluidity.

[0028] According to the embodiments of the present application, the aluminum alloy powder is manufactured by an atomization method, specifically, for example, an argon gas atomization method.

[0029] The present application further provides a method for manufacturing the above aluminum alloy powder, comprising: 1) Mixing materials according to the element composition ratio; 2) Heating and melting the raw materials and performing powder production by atomization; 3) Drying, screening the manufactured powder to obtain the aluminum alloy powder. The present application further includes the use of the above aluminum alloy powder in the repair of aluminum alloy materials, particularly in the repair of aluminum alloy materials used in fields such as high-speed railways, automobiles, and aircraft. In some specific examples, it is used in the repair of axle boxes of railway vehicles such as high-speed trains, urban railways, and subways. The axle box is made of high-strength aluminum alloy, for example, 7050FD high-strength aluminum alloy.

[0030]

[0031] ​Due to the process with low bonding strength of high-pressure cold spray of high-strength aluminum alloy, a method for increasing the bonding strength of high-pressure cold spray of aluminum alloy is provided. This method can apply the high-pressure cold spray technology to important aluminum alloy load-bearing parts, not only restoring the surface state of high-strength aluminum alloy, but also realizing the restoration of the strength and function of important parts, and playing an important promoting role in applying the high-pressure cold spray technology to more industrial fields.

[0032] This application further provides a method for improving the bonding strength of a high-pressure cold spray coating of an aluminum alloy, comprising: 1) sandblasting the area to be repaired; 2) performing high-pressure cold spray using the above aluminum alloy powder; 3) solution treating the workpiece after the spray repair is completed. A method including the above steps is provided.

[0033] Generally, the aluminum alloy powder in this application is dried before use, for example, placed in a vacuum oven for drying. In some embodiments, the drying temperature of the vacuum oven is 60-70°C and the time is 40-60 minutes. After drying, it can be put into a cold spray powder feeding system for spraying.

[0034] According to the embodiments of this application, by performing blasting roughening treatment on the surface of the workpiece to be sprayed, the surface roughness is improved, and the spray process parameters are set according to the depth and area of the repair area. In some specific examples, the surface roughness Ra of the workpiece after sandblasting treatment is 5.0-7.6 μm, for example, Ra reaches 5.8-7.6 μm.

[0035] According to the embodiments of this application, the temperature of the high-pressure cold spray is 350-500°C, for example, 400-500°C, and the gas pressure is 4.5-5.5 MPa, for example, 5-5.5 MPa.

[0036] According to the embodiments of the present application, the speed of the high-pressure cold spray (spray gun) is 250 to 350 mm / s, for example, 300 mm / s.

[0037] According to the embodiments of the present application, the angle of the high-pressure cold spray (spray gun) is 70 to 90°.

[0038] According to the embodiments of the present application, the temperature of the solution treatment is 400 to 500 °C, for example, 455 to 460 °C, and the solution treatment time is 30 min to 60 min, for example, 35 to 40 min.

[0039] According to the embodiments of the present application, the temperature of the high-pressure cold spray is 350 to 500 °C, the gas pressure is 4.5 to 5.5 MPa, the speed of the high-pressure cold spray is 250 to 350 mm / s, the angle of the high-pressure cold spray is 70 to 90°, the temperature of the solution treatment is 400 to 500 °C, and the solution treatment time is 30 min to 60 min. Through research, it is found that when powder particles collide with the substrate under these preferred conditions, they will undergo intense plastic deformation themselves, corresponding depressions will occur on the surface of the substrate, and combined with the influence of the surface roughness of the substrate, excellent bonding quality of the powder particles to the substrate can be generated. The pores inside the coating will also correspondingly decrease or disappear.

[0040] The present application heat-treats the cold-sprayed axle box body after high-pressure cold spraying to achieve extremely high bonding strength and extremely low porosity of the cold-spray coating, solves the problems of low bonding strength and high porosity of general high-pressure cold-spray coatings, and guarantees the service performance of the repaired parts.

[0041] The method provided in this application for repairing damage to the mounting surface of the axle housing innovatively introduces the technical means of cold spray additive manufacturing, which has the function of depositing metal materials in a low-temperature solid state, into the technical means of additive (removal) remanufacturing. By realizing accurate process path design through dimensional measurement and defect classification, the damaged area of the mounting surface of the aluminum alloy axle housing is repaired, different repair processes are formulated for different damage forms, and the problems of high maintenance cost, difficult repair, and serious waste of resources in the conventional maintenance of aluminum alloy axle housings are solved.

[0042] The method described in this application can determine the defect area where removal processing can be realized by measuring the dimensions of the corrosion pits at the damaged position of the mounting surface of the axle housing, and improve the accuracy of the operation of removing the corrosion layer. The method classifies the defect areas in detail and performs corresponding spray treatments on each defect area based on the type of each defect area to achieve precise spraying. Based on this, this method performs removal remanufacturing on each repair area to restore the dimensions of the mounting surface. Compared with the prior art, this method not only simply machines the mounting surface of the axle housing to remove the corroded surface, but in addition to the removal processing, it also performs additive manufacturing repair means on the defect areas corroded by high-pressure cold spray means. It can not only remove the corrosion products on the mounting surface of the axle housing, but also, after removing the corrosion products by machining, sequentially perform additive treatment and removal treatment to efficiently and accurately restore the dimensions of the axle housing, eliminate the influence on the tissue state, dimensional accuracy, and mechanical properties of the parts by the conventional thermal repair means, and further extend the service life of the axle housing.

[0043] Furthermore, the method described in this application can apply the high-pressure cold spray technology to important aluminum alloy load-bearing parts, and can not only restore the surface state of high-strength aluminum alloys, but also realize the repair of the strength and functions of important parts, playing an important promoting role in applying the high-pressure cold spray technology to more industrial fields.

[0044] The present application further provides an apparatus for repairing the damaged mounting surface, and by providing a dimension measurement system, a removal processing system, a spray system, and a removal remanufacturing system, the apparatus for repairing the damaged mounting surface of the axle housing can execute the method for repairing the damaged mounting surface of the above axle housing, and can have all the advantages of the method for repairing the damaged mounting surface of the above axle housing, and specific descriptions are omitted here.

[0045] The aluminum alloy powder provided by the present application mainly contains elements such as Al, Zn, Mg, Cu, Ti, C, Zr, Nd, Sr. The present application adds rare earth elements to refine and strengthen the crystal grains of the powder. Further, by adding Ti and C to the alloy elements, TiC hard particles are precipitated in situ inside the powder particles, improving the strength and hardness of the powder particles. In the process of making particles with higher hardness than the base material collide with the surface of the base material at high speed in the cold spray process, the particles can be effectively embedded in the surface of the base material. As a result, the conventional aluminum alloy powder forms a higher interfacial bonding strength.

[0046] Compared with the conventional cold spray repair technology, this application is based on the additive manufacturing technology of high-pressure cold spray. By optimizing the powder formulation and introducing rare earth elements such as Nd and Sr, it plays the role of strengthening the grain refinement. By adding Ti and C in the alloy elements, TiC hard particles are precipitated in situ inside the powder particles, improving the strength and hardness of the powder particles and achieving better matching with the strength of the substrate. In the spraying process, by setting a low spraying temperature, it avoids excessive softening of metal particles after being heated, and by applying a high gas pressure, it imparts greater kinetic energy to the particles. In the deposition process, not only sufficient flattening deformation occurs to itself, but also the compressive stress between particles inside the coating increases. Therefore, when the particles collide with the substrate, it is more beneficial for a wider area of anchor effect and pinning effect to occur at the interface. At the same time, since the surface oxide films of the powder and the substrate rupture, metallurgical bonding sites are formed under the action of the kinetic energy of particle impact, and the bonding performance is greatly improved. By performing solution treatment on the repaired axle box body after spraying, the internal voids can be shrunk, the element diffusion at the interface can be strengthened, the bonding surface can be solidified, and the bonding strength can be further improved.

Brief Description of Drawings

[0047] The following briefly describes the drawings necessary for the examples or the description of the prior art in order to more clearly explain the technical solutions in this application or the prior art. Of course, the drawings described below are only part of the examples of this application, and those skilled in the art can obtain other drawings based on these drawings without creative efforts.

[0048]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0049] Hereinafter, in order to make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be clearly and completely described with reference to the drawings in the present application. Of course, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor shall fall within the protection scope of the present application.

[0050] Hereinafter, the present application will be further described with reference to the embodiments and comparative examples. The embodiments adopted here mean that there is at least one embodiment in the present application. However, since the present application may also be implemented by adopting other methods different from this embodiment, the present application is not limited to the specific embodiments disclosed below.

[0051] Hereinafter, with reference to FIG. 1, a method for repairing the damaged mounting surface of the axle housing of the present application (abbreviated as "method" in the present application), and an apparatus for repairing the damaged mounting surface of the axle housing (abbreviated as "apparatus" in the present application) will be described.

[0052] As shown in FIG. 1, the method for repairing the damaged mounting surface of the axle housing described in the present application is as follows: Step S1 of obtaining the measurement results of the dimensions of the corrosion pits at the damaged position of the mounting surface of the axle housing, determining the defect area at the damaged position, and removing the corrosion layer of the defect area by machining; Step S2 of classifying the defect areas and performing corresponding spraying treatments on the defect areas respectively based on the types of each defect area to obtain corresponding repair areas; Step S3 of performing removal and remanufacturing on each repair area to restore the dimensions of the mounting surface; and

[0053] In the method described in the present application, in step S1, by measuring the dimensions of the corrosion pits at the damaged position of the mounting surface of the axle box body, a defective area where the removal process can be realized is determined, and the accuracy of the operation of removing the corrosion layer is improved. In step S2, the defective areas are classified in detail, and based on the type of each defective area, a corresponding spraying process is performed on each defective area, thereby realizing precise spraying. Based on this, the method further performs removal and remanufacturing on each repair area in step S3 to restore the dimensions of the mounting surface. Compared with the prior art, the present method not only simply machines the mounting surface of the axle box body to remove the corroded surface, but in addition to the removal process, a repair means of additive manufacturing is performed on the defective areas corroded by high-pressure cold spraying means. It can not only remove the corrosion products on the mounting surface of the axle box body, but also, after removing the corrosion products by machining, sequentially perform additive treatment and removal treatment, so that the dimensions of the axle box body can be efficiently and accurately restored, eliminating the influence on the tissue state, dimensional accuracy, and mechanical performance of the parts by the conventional thermal repair means, and further extending the service life of the axle box body.

[0054] To ensure that the corrosion pits at the damaged position are completely exposed, make the results of subsequent dimensional measurements more accurate, and avoid errors in the subsequent determination and classification of defective areas due to large differences, it is preferable to further include a step of pretreating the surface before step S1.

[0055] Preferably, the step of pretreating the surface specifically includes step S01 of laser cleaning the damaged position of the mounting surface, and step S02 of surface cleaning the damaged position after cleaning to expose the corrosion pits at the damaged position. And

[0056] To remove the rust marks and contaminants on the mounting surface of the axle box body and improve the accuracy and measurement efficiency of the results of subsequent dimensional measurements, preferably, the above steps S01 and S02 further A step of laser cleaning the damaged position on the attachment surface by a laser cleaning system, where the laser power of the laser cleaning system is 50W - 120W and the cleaning time is 2min - 5min, step S011; A step S021 of surface cleaning the damaged position after cleaning with a high-pressure air gun to expose the corrosion pits at the damaged position; It includes.

[0057] In step S011, to ensure that all the corrosion pits within the damaged position are completely exposed, the most preferred cleaning time is 3 minutes.

[0058] In step S021, after laser cleaning, use a high-pressure air gun to clean the surface after laser cleaning again to ensure that there is no residue of contaminants within the damaged position.

[0059] In some embodiments, the above step S1 further includes: A step S11 of respectively determining each defect area of the damaged position based on the positions of the corrosion pits, with at least one corrosion pit included in each defect area; A step S12 of obtaining the maximum depth of the corrosion pits within the same defect area and the area of the corresponding defect area to determine the processing range of machining; A step S13 of removing the corrosion layer of each defect area respectively by a removal machining process within the processing range of each machining; It includes.

[0060] According to step S11, based on the distribution status of corrosion pits, the damage position can be accurately divided into a plurality of defect regions, whereby specific process routes and parameters can be set for each defect region, making the classification and categorization of each defect region at the damage position more accurate and appropriate. Then, in step S12, by measuring the maximum depth of the corrosion pits and the area of the corresponding defect region, the depth and area range of the removal processing in subsequent step S13 are determined. Furthermore, an accurate and clear machining processing range is determined to avoid the removal processing being too deep and too large, and to play a protective role for the mounting surface of the axle housing.

[0061] In some specific embodiments, the above step S12 further includes step S121 of selecting a plurality of corrosion pits in the same defect region, measuring the depth of each selected corrosion pit by a depth measuring instrument respectively, and obtaining the maximum depth of the corrosion pits by comparison; step S122 of measuring the area of the defect region; and step S123 of determining the machining processing range based on the maximum depth of the corrosion pits and the area of the defect region. It includes.

[0062] Preferably, the area of the machining processing range is larger than the area of the defect region, and the depth of the machining processing range is not less than the maximum depth of the corrosion pits. According to this setting, it can be ensured that the range of the removal processing covers the entire defect region, avoiding leakage in the removal operation of the corrosion layer, and while making the range of the removal processing as small as possible, the accuracy of the corrosion layer removal can be improved as much as possible.

[0063] Preferably, in order to play a better protective role for the defect region after the removal processing, preferably, after the above step S13, step S14 of performing a fillet transition processing on the defect region after the removal processing is further included.

[0064] Here, the included angle between the fillet of the defective area after the fillet transition process and the base surface is 30° or less. In other words, this method obtains the corrosion pit with the maximum corrosion depth among a plurality of corrosion pits by detecting the depth of the corrosion pits using a corrosion pit depth measuring instrument, and, taking the depth of the corrosion pit with this maximum corrosion depth as the maximum depth of the corrosion pits, adds 0.2 mm and performs removal processing on the surface of the corrosion pits. Then, a fillet transition process is performed on the peripheral edge of the processing range of the machining, to avoid the appearance of acute angles or right angles, and the included angle with the base surface should be 30° or less.

[0065] Here, the specific steps for measuring the depth of the corrosion pits using the above corrosion pit depth measuring instrument are as follows: The step of placing the mounting surface of the axle housing facing up and placing it on the mounting table in a flat state; The step of bringing the corrosion pit depth measuring instrument close to the mounting surface of the axle housing, gently placing it so that the probe contacts the flat surface, adjusting the micrometer to zero, and then moving the probe closer to the edge of the mounting surface of the axle housing to adjust the height of the probe to be below the depth to be measured of the mounting surface of the axle housing; The step of lifting the probe, moving it directly above the measurement area, and then lowering the probe to perform the measurement; The step of randomly measuring different parts of the corrosion area, setting the number of measurement points to 5 or more, and recording the maximum depth; And that's it.

[0066] After measuring the maximum depth and the area of the corrosion pits, add 0.2 mm to determine the machining process, perform removal processing on the repaired part of the axle housing to remove the corrosion layer, and visually inspect whether the machining depth is sufficient after completion.

[0067] In some embodiments, in order to exert a better protective effect on the mounting surface of the axle housing during the repair process, preferably, between step S1 and step S2, further, Step S15 of plugging all the hole-shaped parts in the defective area after the removal processing with plugs; Step S16 of sandblasting the defective area after the removal process, Step S17 of preheating and spraying the defective area after the sandblasting, and include.

[0068] Preferably, in step S15, for the convenience of operation, the axle box body to be repaired is attached to a dedicated jig. Before blasting, it is preferable to block the hole-shaped parts, especially the thread parts, in the defective area with a dedicated plug to achieve a reliable protection effect. The preferably used dedicated plug is made of a non-metallic material and does not interfere with the spraying path of the particles.

[0069] Preferably, step S16 is to roughen the defective area after the removal process by blasting, so that the surface after blasting is in a uniform and rough state without metallic luster. Preferably, the surface roughness Ra of the defective area after blasting is 5.0 μm to 7.6 μm. Preferably, sandblasting is performed using 25-mesh brown corundum sand, the blasting pressure is 0.3 MPa to 0.6 MPa, the blasting distance is 80 mm to 120 mm, the blasting angle is 40° to 70°, and the blasting time is 2 min to 5 min.

[0070] Preferably, the preheating spray in step S17 can perform a preheating effect on the mounting surface to be repaired, thereby performing a drying process on the powder. Preferably, the process parameters of the preheating spray specifically include using aluminum alloy powder (for example, 7050 aluminum alloy powder) for the preheating spray, the particle size of the powder is 10 μm to 60 μm, the drying temperature of the powder is 70 ± 5 °C, the time of the preheating spray is 40 min to 60 min, the spray gas for the preheating spray is 99.99% nitrogen gas, the gas pressure of the spray gas is 3.5 MPa to 5.5 MPa, the spray distance of the preheating spray is 5 mm to 20 mm, and the angle between the spray gun of the preheating spray and the spray surface is 60° or more.

[0071] In some embodiments, step S2 further Step S21 of obtaining the length and width of each corrosion pit within the defective area A step of classifying the defective area based on the length and width of each corrosion pit and determining the type of the defective area, where the types of the defective area include punctiform defects, linear defects, and planar defects. Step S22 is included.

[0072] By the above step S21, the dimensions of each corrosion pit are accurately obtained. By the above step S22, the defective area is accurately classified, and a unique process route is formulated for different types of defective areas, making the cold spray process more directional and unique and conforming to the process requirements of different areas, thereby improving the efficiency and quality of the spray process.

[0073] Specifically, the above step S22 further includes for punctiform defects, driving the spray gun to spray perpendicularly to the center of the defective area for linear defects, driving the spray gun to proceed along the longitudinal direction of the defective area and ensuring that the proceeding route does not change in the width direction, and further determining the number of reciprocations of the spray gun based on the maximum depth of the corrosion pit for planar defects, driving the spray gun to proceed along the longitudinal and width directions of the defective area respectively, and further determining the number of reciprocations of the spray gun based on the maximum depth of the corrosion pit is included, wherein for punctiform defects, it is preferable that both the length and width of the corrosion pit are less than 5 mm; for linear defects, it is preferable that the length of the corrosion pit is 5 mm or more and the width is 5 mm or less; and the remaining defects excluding punctiform defects and linear defects are all planar defects. It is preferable to set the travel distance of the spray gun in the longitudinal direction of the defect and the moving distance in the width direction of the defect according to the actual area dimensions.

[0074] In addition, in order to further improve the quality and efficiency of the process operation, preferably, when the distance between two or more dot-like defects does not exceed 5 mm, it is regarded as a planar defect, and spray repair is performed according to the spray process of the planar defect. When the distance between two or more linear defects does not exceed 5 mm, it is regarded as a planar defect, and spray repair is performed according to the spray process of the planar defect.

[0075] In some embodiments, the above step S3 further includes machining the repair area using a milling machine, and based on the original drawing, restoring the surface dimensions and roughness of the repair area with the criterion of not damaging the surface, and ensuring the accuracy of the parts.

[0076] The device for repairing the damage to the mounting surface of the axle housing disclosed in the present application is capable of executing the method for repairing the damage to the mounting surface of the axle housing as described above. This device for repairing the damage to the mounting surface of the axle housing includes a dimension measurement system, a removal machining treatment system, a spray system, and a removal remanufacturing system. The dimension measurement system is for obtaining the measurement results of the dimensions of the corrosion pits at the damaged position of the mounting surface of the axle housing. The removal machining treatment system is for determining the defect area at the damaged position and removing the corrosion layer of the defect area by removal machining treatment based on the measurement results of the dimensions of the corrosion pits. The spray system is for classifying the defect areas and performing corresponding spray treatments on the defect areas respectively based on the types of each defect area to obtain corresponding repair areas. The removal remanufacturing system is for performing removal remanufacturing on each repair area to restore the dimensions of the mounting surface.

[0077] By providing the dimension measurement system, the removal machining treatment system, the spray system, and the removal remanufacturing system, the device can execute the method for repairing the damage to the mounting surface of the axle housing as described above, and can have all the advantages of the method for repairing the damage to the mounting surface of the axle housing as described above, and specific descriptions are omitted here.

Embodiment

[0078] The surface roughness was measured using a surface roughness measuring instrument as follows.

[0079] Example 1 This example provides an aluminum alloy powder, and its manufacturing method is as follows. 1) Weigh 2.3% pure Mg powder, 5.3% pure Zn powder, 1.9% Nd powder, 0.9% graphite powder, 0.12% Zr powder, 2.2% Cu powder, 0.04% Ti powder, and 0.04% Sr powder by weight percentage. Use the remaining part as Al powder. Put it into a vacuum melting furnace, fully melt it, then perform powder making by argon gas atomization method at 800 °C. After cooling, collect it. 2) Use a sieve to screen the powder to obtain aluminum alloy powder with a particle size of 10 - 60 μm.

[0080] This example further provides a method for improving the bonding strength of the high - pressure cold spray coating of the aluminum alloy. In this method, 1) Put the aluminum alloy powder manufactured in this example into a vacuum oven for drying. The time is 40 min and the drying temperature is 70 °C. 2) Remove the corrosion layer on the surface to be repaired of the axle housing body, keep it in a dry state, and then perform sandblasting treatment. After the sandblasting treatment, when the surface roughness was measured, Ra was 7.6 μm. Perform high - pressure cold spraying using the aluminum alloy powder dried in step 1). Set the air pressure of the high - pressure cold spraying to 5.0 MPa, the temperature of the spray gun to 400 °C, the speed of the spray gun to 300 mm / s, and the angle of the spray gun to 90°. 3) Solution heat - treat the repaired axle housing body. The treatment temperature is 455 °C, the holding time is 35 min, and it is cooled at 60 °C.

[0081] The electron microscope micro - morphology diagram of the aluminum alloy powder manufactured in this example is shown in Figure 2.

[0082] The aluminum alloy powder produced by the method of this example, due to the addition of rare earth elements, plays a role in strengthening the grain refinement, refining the particle size, suppressing the growth of crystal grains, improving the mechanical strength of the powder particles, and further improving the strength of the powder particles due to the precipitation of the TiC hard phase.

[0083] This example manufactures a repair coating by combining reasonable cold spray process parameters, strengthens the repaired axle housing by solution heat treatment, and finally measures the bonding strength according to the standard GB / T 6396 - 2008. As a result, the bonding strength of the coating reaches 126 MPa and the porosity is less than 0.2%.

[0084] Example 2 This example provides an aluminum alloy powder, and its manufacturing method is as follows. 1) Take 2.2% pure Mg powder, 6.5% pure Zn powder, 1.5% Nd powder, 1.0% graphite powder, 0.15% Zr powder, 2.0% Cu powder, 0.03% Ti powder, 0.05% Sr powder by weight percentage, and use the rest as Al powder. Put it into a vacuum melting furnace, fully melt it, then perform powder making by argon gas atomization method at 800 °C, cool it, and collect it. 2) Screen the powder using a sieve to obtain aluminum alloy powder with a particle size of 15 - 55 μm.

[0085] This example further provides a method for improving the bonding strength of a high - pressure cold spray coating of an aluminum alloy. In this method, 1) Put the aluminum alloy powder produced in this example into a vacuum oven for drying. The time is 1 h and the drying temperature is 60 °C. 2) Remove the corrosion layer on the surface to be repaired of the axle housing, keep it in a dry state, then perform sandblasting treatment. The surface roughness Ra after sandblasting treatment is 5.8 μm. Perform high-pressure cold spraying using the aluminum alloy powder dried in Step 1), and set the air pressure of the high-pressure cold spraying to 5.5 MPa, the temperature of the spray gun to 500 °C, the speed of the spray gun to 300 mm / s, and the angle of the spray gun to 70°. 3) Solution heat treat the repaired axle housing, with the treatment temperature being 460 °C, the holding time being 40 min, and cooling at 65 °C.

[0086] The aluminum alloy powder produced by the method of this example, through the addition of rare earth elements, plays a role in strengthening grain refinement, refines the particle size, suppresses the growth of crystal grains, generates TiC strengthening phases, and further improves the mechanical strength of the powder particles.

[0087] The fine morphology diagram of the internal structure of the repair coating by cold spraying produced in this example is shown in Figure 3.

[0088] This example manufactures a repair coating by combining reasonable cold spraying process parameters, and measures the bonding strength according to GB / T 6396-2008. As a result, the bonding strength of the coating reaches 130 MPa and the porosity is less than 0.2%.

[0089] Example 3 This example provides an aluminum alloy powder, and its manufacturing method is as follows. 1) Take 2.2% pure Mg powder, 6.5% pure Zn powder, 2.5% Nd powder, 1.0% graphite powder, 0.15% Zr powder, 2.0% Cu powder, 0.03% Ti powder, and 0.06% Sr powder by weight percentage, with the balance being Al powder. Put it into a vacuum melting furnace, fully melt it, then perform powder making by argon gas atomization method at 800 °C, cool it, and collect it. 2) Sieve the powder using a sieve to obtain aluminum alloy powder with a particle size of 15 - 55 μm.

[0090] This example further provides a method for improving the bonding strength of a high-pressure cold spray coating of an aluminum alloy. In this method, 1) The aluminum alloy powder produced in this example was placed in a vacuum oven for drying. The drying time was 1 h and the drying temperature was 60 °C. 2) Remove the corrosion layer on the surface to be repaired of the axle housing body, keep it in a dry state, and then perform sandblasting treatment. The surface roughness Ra after sandblasting treatment is 5.8 μm. Using the aluminum alloy powder dried in step 1), high-pressure cold spraying was carried out. The air pressure of the high-pressure cold spraying was set to 5.5 MPa, the temperature of the spray gun was set to 500 °C, the speed of the spray gun was set to 300 mm / s, and the angle of the spray gun was set to 90°. 3) The repaired axle housing body was solution heat-treated. The treatment temperature was 460 °C, the holding time was 40 min, and it was cooled at 65 °C.

[0091] The aluminum alloy powder produced by the method of this example, due to the addition of rare earth elements, plays a role in refining and strengthening the crystal grains, refines the particle size, suppresses the growth of crystal grains, generates TiC strengthening phases, and further improves the mechanical strength of the powder particles.

[0092] This example manufactured a repair coating by combining reasonable cold spraying process parameters. As a result of measuring the bonding strength according to GB / T 6396-2008, the bonding strength of the coating reached 135 MPa and the porosity was less than 0.2%.

[0093] Example 4 This example provides an aluminum alloy powder, and its manufacturing method is as follows. 1) By weight percentage, 2.2% pure Mg powder, 6.5% pure Zn powder, 1.2% Nd powder, 1.0% graphite powder, 0.15% Zr powder, 2.0% Cu powder, 0.03% Ti powder, and 0.02% Sr powder were taken, and the balance was Al powder. It was put into a vacuum melting furnace, melted sufficiently, and then atomized into powder by the argon gas atomization method at 800 °C, and after cooling, it was collected. 2) The powder was sieved using a sieve to obtain aluminum alloy powder with a particle size of 15 - 55 μm.

[0094] This embodiment further provides a method for improving the bonding strength of a high-pressure cold spray coating of an aluminum alloy. In this method, 1) The aluminum alloy powder produced in this embodiment is put into a vacuum oven and dried for 1 h at a drying temperature of 60°C. 2) Remove the corrosion layer on the surface of the shaft housing to be repaired and keep it in a dry state. Then, perform sandblasting treatment, and the surface roughness Ra after sandblasting treatment is 5.8 μm. Perform high-pressure cold spraying using the aluminum alloy powder dried in step 1), and set the air pressure of high-pressure cold spraying to 5.5 MPa, the temperature of the spray gun to 500°C, the speed of the spray gun to 300 mm / s, and the angle of the spray gun to 90°. 3) Solution heat-treat the repaired shaft housing at a treatment temperature of 460°C for a holding time of 40 min and cool it at 65°C.

[0095] The aluminum alloy powder produced by the method of this embodiment, due to the addition of rare earth elements, plays a role in grain refinement strengthening, refines the particle size, suppresses the growth of crystal grains, generates TiC strengthening phases, and further improves the mechanical strength of powder particles.

[0096] This embodiment manufactures a repair coating by combining reasonable cold spray process parameters. As a result of measuring the bonding strength according to GB / T 6396-2008, the bonding strength of the coating layer reaches 125 MPa and the porosity is less than 0.2%.

[0097] Comparative Example 1 This comparative example provides an aluminum alloy powder, and its manufacturing method is as follows. 1) Take 2.2% pure Mg powder, 6.5% pure Zn powder, 1.0% graphite powder, 0.15% Zr powder, 2.0% Cu powder, and 0.03% Ti powder by weight percentage, and use the rest as Al powder. Put it into a vacuum melting furnace, fully melt it, then perform powder making by argon gas atomization method at 800°C, cool it, and collect it. 2) Use a sieve to screen the powder to obtain aluminum alloy powder with a particle size of 15 - 55 μm.

[0098] This comparative example further provides a method for improving the bonding strength of high - pressure cold - spray coating of aluminum alloy. In this method, 1) Put the aluminum alloy powder produced in this comparative example into a vacuum oven for drying. The time is 1 h and the drying temperature is 60 °C. 2) Remove the corrosion layer on the surface to be repaired of the axle box body, keep it in a dry state, and then perform sandblasting treatment. The surface roughness Ra after sandblasting treatment is 5.8 μm. Perform high - pressure cold - spray using the aluminum alloy powder dried in step 1). Set the gas pressure of the high - pressure cold - spray to 3.5 MPa, the temperature of the spray gun to 500 °C, the speed of the spray gun to 300 mm / s, and the angle of the spray gun to 70°.

[0099] The electron microscope micro - morphology diagram of the repair coating by cold - spray produced in this comparative example is shown in Figure 4.

[0100] The aluminum alloy powder produced in the comparative example has no addition of rare - earth elements, the powder particles are not sufficiently strengthened, no hard phase is formed, and it is difficult to match the strength of the substrate. Therefore, a large amount of anchor effect and pinning effect cannot be formed at the interface of the substrate. Moreover, because the gas pressure of the spray gas used is low, sufficient compressive stress does not occur inside the coating. Furthermore, since solution heat treatment is not performed after spraying, the porosity is high. As a result of measuring the bonding strength according to GB / T 6396 - 2008, the bonding strength of the coating is only 48 MPa and the porosity is 0.8%.

[0101] Comparative Example 2 This comparative example provides a method for improving the bonding strength of high - pressure cold - spray coating of aluminum alloy. In this method, 1) Put the aluminum alloy powder produced in Example 2 into a vacuum oven for drying. The time is 1 h and the drying temperature is 70 °C. 2) Remove the corrosion layer on the surface of the axle housing to be repaired, keep it in a dry state, and then perform sandblasting. The surface roughness Ra after sandblasting is 5.8 μm. Using the aluminum alloy powder dried in step 1), perform high-pressure cold spraying. Set the gas pressure of the high-pressure cold spraying to 3.5 MPa, the temperature of the spray gun to 500 °C, the speed of the spray gun to 300 mm / s, and the angle of the spray gun to 70°. 3) Heat-treat the repaired axle housing. The solution treatment temperature is 460 °C, the holding time is 40 min, and it is cooled at 65 °C.

[0102] In this comparative example, the gas pressure of the spray gas used is low, the acceleration effect on the powder particles is limited, the degree of plastic deformation of the particles is normal, and sufficient compressive stress is not generated inside the coating. Therefore, the porosity is high. As a result of measuring the bonding strength according to GB / T 6396-2008, the bonding strength of the coating layer is only 47 MPa, and the porosity is 1.2%.

[0103] Comparative Example 3 This comparative example provides a method for improving the bonding strength of a high-pressure cold spray coating of an aluminum alloy. In this method, 1) Put the aluminum alloy powder manufactured in Example 2 into a vacuum oven and dry it for 1 h at a drying temperature of 70 °C. 2) Remove the corrosion layer on the surface of the axle housing to be repaired, keep it in a dry state, and then perform sandblasting. The surface roughness Ra after sandblasting is 5.8 μm. Using the aluminum alloy powder dried in step 1), perform high-pressure cold spraying. Set the gas pressure of the high-pressure cold spraying to 5.5 MPa, the temperature of the spray gun to 500 °C, the speed of the spray gun to 300 mm / s, and the angle of the spray gun to 70°.

[0104] The gas pressure of the spray gas used in this comparative example is high, but since strengthening by melting is not performed after spraying, internal defects cannot be further eliminated, the diffusion of interface elements cannot be enhanced, and the bonding surface cannot be hardened. As a result of measuring the bonding strength in accordance with GB / T 6396-2008, the bonding strength of the coating is 89 MPa and the porosity is 0.8%.

[0105] Comparative Example 4 This comparative example provides aluminum alloy powder, and its manufacturing method is as follows. 1) By weight percentage, 2.3% pure Mg powder, 5.3% pure Zn powder, 0.9% Nd powder, 0.9% graphite powder, 0.12% Zr powder, 2.2% Cu powder, 0.04% Ti powder, 0.01% Sr powder are collected, and the balance is Al powder. It is put into a vacuum melting furnace, melted sufficiently, then pulverized by the argon gas atomization method at 800 °C, cooled, and collected. 2) The powder is sieved using a sieve to obtain aluminum alloy powder with a particle size of 15 - 55 μm.

[0106] Using the aluminum alloy powder produced in this comparative example, the axle box body is repaired in the same manner as in Example 1. Since the addition amounts of Nd element and Sr element in the aluminum alloy powder produced in this comparative example are decreased, the hardening effect of the powder is affected. As a result of measuring the bonding strength in accordance with GB / T 6396-2008, the bonding strength of the coating is 103 MPa and the porosity is 0.3%.

[0107] Comparative Example 5 This comparative example provides aluminum alloy powder, and its manufacturing method is as follows. 1) By weight percentage, 2.3% pure Mg powder, 5.3% pure Zn powder, 3.0% Nd powder, 0.9% graphite powder, 0.12% Zr powder, 2.2% Cu powder, 0.04% Ti powder, 0.1% Sr powder are collected, and the balance is Al powder. It is put into a vacuum melting furnace, melted sufficiently, then pulverized by the argon gas atomization method at 800 °C, cooled, and collected. 2) The powder is sieved using a sieve to obtain aluminum alloy powder with a particle size of 15 - 55 μm.

[0108] Using the aluminum alloy powder produced in this comparative example, the axle housing is repaired in the same manner as in Example 1. Since the addition amounts of Nd element and Sr element in the aluminum alloy powder produced in this comparative example increased, powder mixing was likely to occur, the porosity increased, the internal structure of the coating became loose, and as a result of measuring the bonding strength according to the standard GB / T 6396-2008, the bonding strength of the coating was 92 MPa and the porosity was 0.7%.

[0109] In the description of the embodiments of the present application, the orientation or positional relationship indicated by terms such as "center", "vertical", "horizontal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. This is only for the convenience of the description of the embodiments of the present application and to simplify the description, and it does not indicate or imply that the devices or elements mentioned must have a specific orientation and be configured and operated in a specific orientation. Therefore, it should not be understood as limiting the embodiments of the present application. Also, terms such as "first", "second", "third", etc. are only for the purpose of explanation and should not be understood as indicating or implying relative importance.

[0110] In the description of the embodiments of the present application, unless there are specific and clear regulations and limitations, terms such as "continuous" and "connected" should be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection, and it may be a mechanical connection or an electrical connection, and it may be a direct connection or an indirect connection through an intermediate medium. A person skilled in the art can understand the specific meaning of the above terms in the embodiments of the present application according to the specific situation.

[0111] In the embodiments of the present application, unless there are particularly clear regulations and limitations, the fact that the first feature is "above" or "below" the second feature may mean that the first feature is in direct contact with the second feature, or it may mean that the first feature and the second feature are indirectly in contact through an intermediate medium. Also, the fact that the first feature is "above", "upper" and "upper surface" of the second feature may mean that the first feature is directly above or obliquely above the second feature, or it may only mean that the horizontal height of the first feature is higher than that of the second feature. The fact that the first feature is "below", "lower" and "lower surface" of the second feature may mean that the first feature is directly below or obliquely below the second feature, or it may only mean that the horizontal height of the first feature is lower than that of the second feature.

[0112] In the description of this specification, the description of reference terms such as "one embodiment", "several embodiments", "example", "specific example", or "several examples" means that the specific features, structures, materials or characteristics described by combining the said embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In this specification, the exemplary expressions of the above terms are not necessarily for the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. Also, unless they are mutually contradictory, those skilled in the art can combine or combine different embodiments or examples described in this specification, and the features of different embodiments or examples.

[0113] In the above, the present application has been described in detail in general description and specific embodiments, but it is obvious to those skilled in the art that some corrections and improvements can be made based on the present application. It should be noted that the above embodiments are only for explaining the technical solutions of the present invention and not for limiting the technical solutions of the present invention. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that it is still possible to correct the technical solutions described in the foregoing embodiments or perform equivalent substitution on some of the technical features therein. These corrections or substitutions do not deviate the gist of the corresponding technical solutions from the scope of the technical solutions of each embodiment of the present invention.

Claims

1. Obtaining a measurement result of the dimensions of corrosion pits at the damaged position on the mounting surface of the axle housing body, determining the defective region at the damaged position, and removing the corrosion layer in the defective region by a machining process; Classifying the defective regions, and performing corresponding spraying processes on each of the defective regions based on the type of each defective region to obtain corresponding repair regions; Performing removal and remanufacturing on each of the repair regions to restore the dimensions of the mounting surface A method for repairing damage to the mounting surface of an axle housing body, including the above steps.

2. The step of obtaining a measurement result of the dimensions of corrosion pits at the damaged position on the mounting surface of the axle housing body, determining the defective region at the damaged position, and removing the corrosion layer in the defective region by a machining process is: Based on the positions of the corrosion pits, determining each defective region at the damaged position, with at least one of the corrosion pits included in each defective region; Obtaining the maximum depth of the corrosion pits in the same defective region and the area of the corresponding defective region to determine the machining range; Within each machining range, removing the corrosion layer in each defective region by the machining process The method for repairing damage to the mounting surface of an axle housing body according to Claim 1, further including the above steps.

3. The step of obtaining the maximum depth of the corrosion pits in the same defective region and the area of the corresponding defective region to determine the machining range is: Selecting a plurality of the corrosion pits in the same defective region, measuring the depth of each selected corrosion pit with a depth measuring instrument, and obtaining the maximum depth of the corrosion pits by comparison; Measuring the area of the defective region; Based on the maximum depth of the corrosion pits and the area of the defective region, determining the machining range Further including the above steps, wherein the area of the machining range is larger than the area of the defective region, and the depth of the machining range is not less than the maximum depth of the corrosion pits. The method for repairing damage to the mounting surface of an axle housing body according to Claim 2.

4. After the step of removing the corrosion layer in each defective region by the machining process within each machining range, Further including the step of performing a fillet transition process on the defective region after the machining process. The method for repairing the damaged mounting surface of the axle box body according to claim 2, wherein the included angle between the fillet of the defect area after the fillet transition process and the base surface is 30° or less.

5. The step of classifying the defect areas and performing corresponding spraying processes on the defect areas respectively based on the types of the defect areas to obtain corresponding repair areas is as follows: The step of obtaining the length and width of each corrosion pit in the defect area; The step of classifying the defect areas based on the length and width of each corrosion pit and determining the types of the defect areas, where the types of the defect areas include dot-like defects, linear defects, and planar defects; For the dot-like defects, the step of driving a spray gun to spray perpendicularly to the center of the defect area; For the linear defects, the step of driving the spray gun to proceed along the longitudinal direction of the defect area and ensuring that the proceeding path does not change in the width direction, and further determining the number of reciprocations of the spray gun based on the maximum depth of the corrosion pit; For the planar defects, the step of driving the spray gun to proceed along the longitudinal direction and the width direction of the defect area respectively, and further determining the number of reciprocations of the spray gun based on the maximum depth of the corrosion pit The method for repairing the damaged mounting surface of the axle box body according to claim 2, further comprising the above steps.

6. For the dot-like defects, both the length and width of the corrosion pit are less than 5 mm; for the linear defects, the length of the corrosion pit is 5 mm or more and the width is 5 mm or less; and all the remaining defects except the dot-like defects and the linear defects are planar defects. The method for repairing the damaged mounting surface of the axle box body according to claim 5.

7. Before the step of obtaining the measurement results of the dimensions of the corrosion pits at the damaged position of the mounting surface of the axle box body, determining the defect area at the damaged position, and removing the corrosion layer of the defect area by machining, The step of laser cleaning the damaged position of the mounting surface; The step of surface cleaning the damaged position after cleaning to expose the corrosion pits at the damaged position The method for repairing the damaged mounting surface of the axle box body according to any one of claims 1 to 6, further comprising the above steps.

8. The step of laser cleaning the damaged position of the mounting surface and surface cleaning the damaged position after cleaning to expose the corrosion pits at the damaged position is as follows: A step of laser cleaning the damaged position of the mounting surface by a laser cleaning system, where the laser power of the laser cleaning system is 50 W to 120 W and the cleaning time is 2 min to 5 min; A step of surface cleaning the damaged position after cleaning with a high-pressure air gun to expose the corrosion pits at the damaged position; The method for repairing the damage to the mounting surface of the axle box body according to claim 7, further comprising.

9. Before the step of classifying the defect regions and performing corresponding spraying treatments on the defect regions respectively based on the types of the defect regions to obtain corresponding repair regions, A step of plugging all the hole-shaped parts in the defect region after the removal processing with plugs; A step of sandblasting the defect region after the removal processing; A step of preheating and spraying the defect region after the sandblasting; The method for repairing the damage to the mounting surface of the axle box body according to any one of claims 1 to 6, further comprising.

10. The method for repairing the damage to the mounting surface of the axle box body according to claim 9, wherein the surface roughness Ra of the defect region after the sandblasting is 5.0 μm to 7.6 μm.

11. The process parameters of the preheating spray are as follows: Aluminum alloy powder is used for the preheating spray, the particle size of the powder is 10 μm to 60 μm, the drying temperature of the powder is 70 ± 5 °C, the time of the preheating spray is 40 min to 60 min, The spray gas used for the preheating spray is 99.99% nitrogen gas, The gas pressure of the spray gas is 3.5 MPa to 5.5 MPa, The spray distance of the preheating spray is 5 mm to 20 mm, The angle between the spray gun and the spray surface of the preheating spray is 60° or more. The method for repairing the damage to the mounting surface of the axle box body according to claim 9, including this.

12. A dimension measurement system for obtaining the measurement results of the dimensions of the corrosion pits at the damaged position of the mounting surface of the axle box body; Based on the measurement results of the dimensions of the corrosion pits, a removal processing system for determining the defect region at the damaged position and removing the corrosion layer of the defect region by removal processing; A spray system for classifying the defect regions and performing corresponding spraying treatments on the defect regions respectively based on the types of the defect regions to obtain corresponding repair regions. A removal remanufacturing system for performing removal remanufacturing on each of the repair areas to restore the dimensions of the mounting surface An apparatus for repairing damage to the mounting surface of a journal box body, which is capable of executing the method for repairing damage to the mounting surface of a journal box body according to any one of claims 1 to 11 and includes the same

13. An aluminum alloy powder used in the method for repairing damage to the mounting surface of a journal box body according to claim 11, containing, by weight percentage, 3.2 to 7.8% of Zn, 2.0 to 2.7% of Mg, 1.5 to 2.9% of Cu, 0.02 to 0.06% of Ti, 0.3 to 1.5% of C, 0.05 to 0.20% of Zr, 1.0% to 2.8% of Nd, 0.01 to 0.08% of Sr, with the balance being Al

14. The aluminum alloy powder contains, by weight percentage, 1.2 to 2.5% of Nd and / or 0.02 to 0.06% of Sr Optionally, the aluminum alloy powder contains, by weight percentage, 2.2 to 2.3% of Mg, 5.3 to 6.5% of Zn, 1.2 to 2.5% of Nd, 0.9 to 1.0% of C, 0.12 to 0.15% of Zr, 2.0 to 2.2% of Cu, 0.03 to 0.04% of Ti, 0.02 to 0.06% of Sr, with the balance being Al, and is the aluminum alloy powder according to claim 13

15. 1) Blending materials in terms of elemental composition ratios 2) Heating and melting the raw materials and performing powder production by atomization 3) Drying the produced powder, sieving, and obtaining aluminum alloy powder A method for manufacturing aluminum alloy powder according to claim 13 or 14, including the above steps

16. In the powder production by atomization, the argon gas atomization method is adopted for the method for manufacturing aluminum alloy powder according to claim 15

17. An aluminum alloy powder produced by the method according to claim 15 or 16

18. Use of the aluminum alloy powder according to any one of claims 13 to 14 and 17 in the repair of an aluminum alloy material

19. 1) Performing sandblasting on the area to be repaired 2) Performing high-pressure cold spraying using the aluminum alloy powder according to any one of claims 13 to 14 and 17 3) Solution-treating the workpiece on which spraying repair has been completed A method for improving the bonding strength of a high-pressure cold spray coating of an aluminum alloy, including the above steps

20. The method according to claim 19, wherein the surface roughness Ra of the workpiece after the sandblasting treatment reaches 5.0 to 7.6 µm, and optionally, Ra is 5.8 to 7.6 µm.

21. The method according to claim 19 or 20, wherein the temperature of the high-pressure cold spray is 350 to 500 °C, the gas pressure is 4.5 to 5.5 MPa, and / or the temperature of the solution treatment is 400 to 500 °C, and the solution treatment time is 30 min to 60 min.

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