A method for remanufacturing and reinforcing a drive wheel of an excavator based on laser cladding

Abstract

The application relates to a laser cladding-based remanufacturing and reinforcing treatment method for excavator driving wheels, and belongs to the technical field of laser additive manufacturing and surface engineering; the worn excavator driving wheel is cleaned and detected, and is processed into a profiled repair groove; laser cladding powder is selected and matched; gradient laser cladding under profiled cooling is carried out; multi-layer laser cladding cladding of the gradient process is carried out under synchronous powder feeding and inert gas protection; post-processing and finishing, stress relief annealing treatment and heat preservation, tooth profile grinding processing according to design drawings, and finally magnetic powder or coloring flaw detection; the heat deformation problem of the complex tooth profile structure is solved, profiled profiled cooling tooling and closed loop temperature control are combined, and the problem that the gear parts such as the driving wheel have large differences in cross section thickness, uneven heat dissipation conditions and are prone to warping and tooth profile deformation out-of-tolerance during laser multi-layer cladding is specially overcome.

Description

Technical Field

[0001] This invention relates to a method for remanufacturing and strengthening excavator drive wheels based on laser cladding, belonging to the field of laser additive manufacturing and surface engineering technology. Background Technology

[0002] Excavators, as important construction machinery, are widely used in earthwork construction in mining, building, and water conservancy fields. The drive wheels are one of the key components of the excavator's walking mechanism, directly meshing with the tracks during operation and bearing enormous alternating loads and severe frictional wear. Prolonged operation in harsh conditions such as mud, sand, or gravel can easily lead to wear, pitting, plastic deformation, and even tooth breakage on the drive wheel teeth and meshing surfaces, resulting in insufficient movement, track jamming, or even complete malfunction of the excavator.

[0003] Currently, the conventional repair methods for worn drive wheels are mainly welding repair or thermal spraying repair. While welding repair offers high bonding strength, it involves significant heat input, easily leading to thermal deformation and structural damage to the drive wheel substrate. Furthermore, the uneven hardness distribution of the weld layer results in substantial subsequent processing. Although thermal spraying repair has a smaller heat-affected zone, the coating and substrate are primarily mechanically bonded, resulting in limited bonding strength and susceptibility to peeling under heavy-load impact conditions. In addition, these methods struggle to simultaneously achieve dimensional restoration and surface strengthening, often resulting in repaired drive wheels with lower wear resistance than original factory-made wheels and a limited service life.

[0004] Laser cladding, as an advanced surface modification and remanufacturing technology, offers advantages such as low heat input, metallurgical bonding between the cladding layer and the substrate, dense microstructure, and high degree of automation, providing a new technical approach for high-quality repair of drive wheels. However, existing laser cladding repair technologies are mostly designed for other types of parts or operating conditions and cannot be directly applied to excavator drive wheels. For example, Chinese patent CN202311786402.4 discloses a welding method for weld metal powder and low-temperature pipe bending. The object of the treatment is pipe weld, and the working condition is low-temperature impact, which is completely different from the high-stress abrasive wear and alternating contact load borne by the tooth surface of the drive wheel. Another patent CN202311747471.4 discloses a laser cladding repair method for 30Cr13 steel impeller shaft. The substrate is martensitic stainless steel, and the object of repair is the outer cylindrical surface of the shaft. Its heat conduction boundary and stress distribution are significantly different from the drive wheel gear structure with complex tooth shape and drastic changes in cross-sectional thickness. Directly applying the powder composition or process parameters of the above-mentioned prior art to the repair of the drive wheel tooth surface is difficult to solve the non-uniform thermal deformation caused by uneven heat dissipation at the tooth tip and tooth root during the multi-layer cladding process, and it is also impossible to guarantee the consistency of the cladding layer performance at different positions of the tooth surface.

[0005] Therefore, designing a dedicated laser cladding process and alloy powder system for the specific working conditions of excavator drive wheels—namely, medium-carbon tempered steel substrate, complex tooth surface profile, and a combined failure mode of high impact and abrasive wear—to accurately restore tooth dimensions while achieving a high-strength metallurgical bond between the cladding layer and the substrate, and significantly improving the impact and abrasive wear resistance of the tooth surface, is a pressing technical problem in this field. This invention is proposed based on this need. Summary of the Invention

[0006] To address the shortcomings of the prior art, this invention provides a method for remanufacturing and strengthening excavator drive wheels based on laser cladding.

[0007] The technical solution of this invention to solve the above-mentioned technical problems is as follows: A method for remanufacturing and strengthening excavator drive wheels based on laser cladding, comprising the following steps: Step 1: Pre-treatment and contouring of the drive wheels The worn excavator drive wheel is cleaned and inspected; firstly, the worn tooth surface of the drive wheel is machined to remove the fatigue layer, and then the worn area is machined into a contour repair groove with a smooth transition bevel according to the original tooth profile design drawing of the drive wheel; Step 2: Selection of cladding powder The selected iron-based alloy powder has the following composition and mass percentage: C: 0.18-0.25%, Cr: 14.0-16.0%, Ni: 1.5-2.5%, Mo: 0.8-1.2%, Si: 0.8-1.0%, Mn: 0.4-0.6%, B: 1.0-1.3%, with the balance being Fe; Step 3: Gradient laser cladding under conformal cooling Step 31: Using a synchronous powder feeding method, laser multi-layer cladding is performed on the pretreated drive wheel tooth surface under inert gas protection; During the cladding process, the conformal cooling fixture is tightly fitted to the drive wheel tooth groove and the side of the wheel body. The conformal cooling fixture consists of two opposing copper alloy pressure blocks. The working surfaces of the two pressure blocks are adapted to the shape of the drive wheel tooth groove, tooth side and the side of the wheel body. The pressure blocks are equipped with circulating water channels. Along the scanning direction, a dual-color infrared thermometer is fixedly installed behind the laser cladding head. The probe optical path of the dual-color infrared thermometer is aligned with the surface of the cladding layer or the substrate area adjacent to the surface of the cladding layer. The output signal of the infrared thermometer is transmitted to the PLC or industrial control computer in real time and linked with the electromagnetic regulating valve on the cooling water circulation system to form a closed-loop temperature control. Step 32: The laser cladding is a multi-layer cladding process using a gradient technique. For the bottom layer cladding, a laser power of 2200-2600W is used, the scanning speed is 10-15mm / s, the single layer thickness is 0.3-0.5mm, and 1-2 layers are clad to obtain a metallurgical bonding interface with a dilution rate of ≤8%. The intermediate and top layers are clad, and 2-4 more layers are clad on top of the bottom layer. The laser power is 3000-3500W, the scanning speed is 5-8mm / s, and the thickness of a single layer is 0.5-0.8mm to obtain a reinforced layer with high hardness and high wear resistance. Step 4: Post-processing and finishing The clad drive wheel is subjected to stress-relief annealing and heat preservation, then cooled in the furnace. The tooth profile is then ground according to the design drawings to accurately restore the tooth profile, tooth pitch and surface roughness. Finally, the repaired tooth surface is subjected to magnetic particle or dye penetrant testing.

[0008] Furthermore, the angle between the smooth bevel and the horizontal line in step 1 is in the range of 15-30°.

[0009] Furthermore, in step 1, the bottom of the contour repair groove is reserved with a cladding allowance of 0.3 mm to 0.5 mm.

[0010] Furthermore, in step 31, the conformal cooling fixture is connected to the drive wheel via a quick-change clamp or bolt tightening mechanism.

[0011] Furthermore, in step 31, the working surfaces of the two pressure blocks are precisely machined according to the contours of the drive wheel tooth groove, tooth side and wheel body side to form a mating surface that is compatible with and complementary to the concave and convex shapes of the drive wheel tooth groove, tooth side and wheel body side. The inlet and outlet of the circulating water channel are connected in parallel to the external cooling water circulation system via flexible hoses.

[0012] Furthermore, in step 31, when the dual-color infrared thermometer detects that the substrate temperature exceeds 200°C or the interlayer temperature exceeds 150°C, the cooling water flow rate is automatically increased or the laser power / scanning speed is reduced.

[0013] Furthermore, in step 1, the powder particle size is 45-105 μm.

[0014] Furthermore, in step 3, the overall process parameters of laser cladding are: spot diameter 3-5mm, overlap rate 40-50%, powder feeding amount 15-20g / min, and multi-layer cladding to restore the size of the wear part of the drive wheel to the design size negative tolerance and reserve a processing allowance of 0.2-0.3mm.

[0015] Furthermore, in step 3, a dual-color infrared thermometer is fixedly installed at a distance of 50-80mm behind the laser cladding head along the scanning direction.

[0016] Furthermore, in step 4, after stress-relieving annealing, the clad drive wheel is kept at 480-520℃ for 1-2 hours.

[0017] The beneficial effects of this invention are: it is highly targeted and solves the problem of thermal deformation of complex tooth structures. This invention adopts a combination of contour-following cooling fixture and closed-loop temperature control to specifically overcome the problem that gear parts such as drive wheels with large differences in cross-sectional thickness and uneven heat dissipation conditions are prone to warping or excessive tooth deformation during laser multilayer cladding.

[0018] This invention achieves precise control of the gradient performance of the tooth surface. In response to the combined requirements of "strong and tough matrix and high wear resistance of surface layer" for the tooth surface of the drive wheel, the invention designs a gradient cladding process with low dilution rate of the bottom layer to ensure bonding and high hardness of the surface layer to ensure wear resistance, and provides narrow window process parameters optimized for 40Mn2 steel.

[0019] The specialized powder formulation delivers unexpected resistance to impact abrasive wear. The narrowed powder composition of this invention (especially the content of C, Cr, and B), after gradient processing and post-treatment, can generate in-situ dispersed M7C3 and M... 23 C6 type carbides are uniformly distributed on a fine-grained martensite matrix with a small amount of retained austenite. This microstructure exhibits excellent resistance to spalling and scratching under combined working conditions of high-stress impact and abrasive particles. Attached Figure Description

[0020] Figure 1 This is a SEM image of the laser cladding layer in Embodiment 1 of the present invention.

[0021] Figure 2 This is a metallographic diagram of the laser cladding layer in Embodiment 1 of the present invention.

[0022] Figure 3 This is a curve comparing the friction coefficients of the cladding layer and the substrate in Embodiment 1 of the present invention.

[0023] Figure 4 This is a bar chart comparing the wear of the cladding layer and the substrate in Embodiment 1 of the present invention.

[0024] Figure 5 The images shown are SEM images of the surface morphology of the cladding layer before and after wear in Embodiment 1 of the present invention. Detailed Implementation

[0025] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0026] A method for remanufacturing and strengthening excavator drive wheels based on laser cladding includes the following steps: Step 1: Pre-treatment and contouring of the drive wheels The worn excavator drive wheel is cleaned and inspected, the worn tooth surface is machined to remove the fatigue layer, and according to the original tooth profile design drawings of the drive wheel, the worn area is machined into a contour repair groove with a smooth transition bevel (bevel angle 15-30°), with a 0.3-0.5mm cladding allowance reserved at the bottom of the groove. The contour-following cooling fixture is connected to the drive wheel via a quick-change clamp or bolt tightening mechanism. Step 2: Selection of cladding powder The selected iron-based alloy powder is specifically designed for medium carbon steel substrates and has the ability to resist abrasive wear. Its composition and mass percentage are as follows: C: 0.18-0.25%, Cr: 14.0-16.0%, Ni: 1.5-2.5%, Mo: 0.8-1.2%, Si: 0.8-1.0%, Mn: 0.4-0.6%, B: 1.0-1.3%, with the balance being Fe. The powder particle size is 45-105μm. Step 3: Gradient laser cladding under conformal cooling Step 31: Using a synchronous powder feeding method, laser multi-layer cladding is performed on the pre-treated tooth surface of the drive wheel under inert gas protection. During the cladding process, a contour-following cooling fixture is used to closely fit the non-repaired surfaces of the drive wheel (especially the tooth grooves and wheel body sides). This fixture consists of two opposing copper alloy pressure blocks. The working surface of each pressure block is precisely machined to form a complementary contact surface with the non-repaired surfaces of the drive wheel, based on the contours of the drive wheel tooth grooves, tooth sides, and wheel body sides. In other words, the working surfaces of the two pressure blocks are adapted to the shapes of the drive wheel tooth grooves, tooth sides, and wheel body sides. Each pressure block has a circulating water channel (with an inlet and an outlet) inside, which is connected in parallel to an external cooling water circulation system via a flexible hose. The entire fixture is fixed to the drive wheel by a quick-change clamp or bolt tightening mechanism to ensure that the pressure blocks remain in contact with the non-repaired surfaces throughout the cladding process. Meanwhile, a dual-color infrared thermometer is fixedly installed 50-80mm behind the laser cladding head (along the scanning direction). Its probe optical path is aligned with the surface of the cladding layer or the substrate area adjacent to the surface of the cladding layer (the spot diameter is about 2-3mm). The output signal of the infrared thermometer is transmitted to the PLC or industrial control computer in real time, and is linked with the electromagnetic regulating valve of the cooling water circulation system to form a closed-loop temperature control. When the substrate temperature exceeds 200℃ or the interlayer temperature exceeds 150℃, the cooling water flow rate is automatically increased or the laser power / scanning speed is reduced. Through the above structure and control method, it is ensured that the highest substrate temperature does not exceed 200℃ and the interlayer temperature does not exceed 150℃ during the cladding process. Step 31: The laser cladding is a multi-layer cladding process, and a gradient process is used. Bottom layer cladding: Using laser power of 2200-2600W, scanning speed of 10-15mm / s, single layer thickness of 0.3-0.5mm, cladding 1-2 layers, the purpose is to obtain a metallurgical bonding interface with low dilution rate ≤8% and no defects; Intermediate and top layer cladding: 2-4 layers are clad on top of the bottom layer, using a laser power of 3000-3500W, a scanning speed of 5-8mm / s, and a single layer thickness of 0.5-0.8mm, in order to obtain a reinforced layer with high hardness and high wear resistance. The overall process parameters are: spot diameter 3-5mm, overlap rate 40-50%, powder feeding rate 15-20g / min, and multi-layer cladding to restore the dimensions of the worn parts of the drive wheel to the design negative tolerance (leaving a machining allowance of 0.2-0.3mm). Step 4: Post-processing and finishing The clad drive wheel is subjected to stress-relief annealing at a temperature of 480-520℃ for 1-2 hours and then cooled in the furnace. The tooth profile is then ground according to the design drawings to accurately restore the tooth profile, tooth pitch and surface roughness. Finally, the repaired tooth surface is subjected to magnetic particle or dye penetrant testing. Example

[0027] This embodiment describes the laser cladding remanufacturing and strengthening treatment of a worn drive wheel of a certain model of excavator. The drive wheel base material is 40Mn2 steel, and the wear depth of the wheel teeth is approximately 2.5mm.

[0028] Step 1. Pretreatment: The drive wheel is ultrasonically cleaned in acetone to remove surface oil. The worn area is then machined to remove the surface fatigue layer, machining to the depth to expose the fresh metal substrate. The surface roughness Ra is controlled at 3.2-6.3 μm. The actual dimensions after machining are measured and recorded. Step 2. Selection of cladding powder: Select iron-based alloy powder prepared by gas atomization, with the following composition by mass percentage: C 0.2%, Cr 15.0%, Ni 2.0%, Mo 1.0%, Si 1.0%, Mn 0.5%, B 1.2%, and the balance being Fe. The powder is vacuum-dried at 120℃ for 2 hours before use. Step 3. Laser Cladding: An IPG fiber laser is used in conjunction with a coaxial powder feeding nozzle. Cladding is performed under argon protection. The process parameters are set as follows: laser power 2800W, spot diameter 4mm, scanning speed 8mm / s, overlap rate 50%, powder feeding rate 18g / min. Multi-layer overlapping cladding is performed on the working surface of the drive wheel teeth, with a total of 4 layers and a total thickness of approximately 2.8mm (leaving a 0.3mm machining allowance). Before cladding, the contouring blocks of the conformal cooling fixture are attached to the non-repaired surfaces of the drive wheel (tooth grooves and wheel sides), and locked with quick-change clamps. Cooling water is then connected (water temperature 20-25℃, flow rate 5-8L / min). A dual-color infrared thermometer is installed behind the laser cladding head, with its probe aimed at the rear area of ​​the cladding layer. During the cladding process, the closed-loop control system stabilizes the measured temperature of the substrate below 150℃. The conformal fixture effectively removes heat input, and the tooth deformation is measured to be less than 0.05mm. Step 4. Post-processing and inspection: After the cladding is completed, the drive wheel is placed in a heat treatment furnace for stress relief annealing at 500℃ for 1.5 hours and then cooled with the furnace. Then, turning and grinding are performed to restore the design size and accuracy of the wheel teeth. The repaired area is subjected to dye penetrant testing. The results show that the cladding layer has no cracks or pores and is of qualified quality.

[0029] Microstructure and performance testing: SEM observation: Scanning electron microscopy was performed on the cross-section of the cladding layer. The results showed that a clear and dense metallurgical bonding zone was formed between the cladding layer and the substrate. There were no defects such as cracks or lack of fusion. The internal structure of the cladding layer was uniform and dense with fine grains. Metallographic analysis: Under a metallographic microscope, the cladding layer structure is mainly composed of fine martensite, retained austenite, and carbides, which is a typical structure for obtaining high hardness and wear resistance. Microhardness test: The average microhardness of the cladding layer surface is HV. 0.2 650, significantly higher than the matrix hardness (approximately HV). 0.2 280), and the hardness distribution from the interface to the surface of the cladding layer is gradient, which is beneficial for load bearing; Friction and wear test: The wear resistance of the cladding layer and the substrate was tested using a ball-and-disc friction and wear tester (load 50N, rotation speed 200rpm, time 30min). The results showed that the friction coefficient of the cladding layer was stable at around 0.45, which was lower than that of the substrate (0.65); the wear of the cladding layer was reduced by about 70% compared with the substrate. SEM analysis of wear morphology: Observation of the surface morphology after wear shows that the substrate surface has obvious ploughing grooves and adhesion marks, indicating severe wear; while the cladding layer surface only shows slight scratches, and the wear mechanism is mainly slight abrasive wear, which proves its excellent wear resistance. Example

[0030] This embodiment is basically the same as Embodiment 1, except that the laser cladding adopts a gradient process: the first layer (bottom layer) uses a laser power of 2400W and a scanning speed of 12mm / s to obtain a lower dilution rate and ensure bonding strength; the second to fourth layers (top layers) use a laser power of 3200W and a scanning speed of 6mm / s to improve the hardness and wear resistance of the top layer. Test results show that, after adopting the gradient process, the surface hardness of the cladding layer is further increased to HV. 0.2 700, with superior wear resistance.

[0031] Comparative Example 1 A worn drive wheel of the same model was repaired using a traditional CO2 gas shielded welding method, with commonly used wear-resistant welding wire as the welding material. Results showed that the weld overlay bonded well to the substrate, but the high heat input during welding resulted in significant overall deformation of the drive wheel, making subsequent straightening difficult. The weld overlay had a hardness of HRC 48 (approximately HV 480), a coarse microstructure, and numerous pores. Friction and wear tests showed that the wear of the weld overlay was approximately 2.5 times that of the cladding layer in Example 1.

[0032] Comparative Example 2: Using low-carbon, low-chromium, and boron-free iron-based powder with a composition similar to that in Comparative Document 1 (CN202311786402.4), the drive wheel was repaired using the same process of this invention. The results showed that the hardness of the cladding layer was only HV. 0.2 480. In the wear test under simulated excavation conditions, the wear amount was 2.8 times that of this embodiment, and large-area spalling occurred, verifying that the special high-carbon, high-chromium, and boron-containing powder of the present invention is a non-obvious key choice for drive wheel conditions.

[0033] Comparative Example 3: Without using conformal cooling fixtures, only conventional air blowing cooling was used. The results showed that after 4 layers of cladding, the tooth profile of the drive wheel underwent a torsional deformation of more than 0.15mm. It could not be completely corrected by grinding, resulting in repair failure. This proves that conformal cooling fixtures are necessary for parts such as drive wheels and have achieved good results.

[0034] In summary, this invention achieves high-quality remanufacturing of excavator drive wheels by optimizing the laser cladding process and material system. The repaired drive wheels not only restore dimensional accuracy, but their wear resistance is even better than that of new products, resulting in significant economic and social benefits.

[0035] This invention is highly targeted, solving the problem of thermal deformation in complex tooth structures. It employs a combination of contour-following cooling fixtures and closed-loop temperature control to specifically overcome the warping and excessive tooth deformation issues that easily occur in gear parts like drive wheels during laser multi-layer cladding, which suffer from large differences in cross-sectional thickness and uneven heat dissipation. It achieves precise control of the tooth surface gradient performance. Addressing the combined requirements of "strong and tough matrix and high wear resistance surface" for drive wheel tooth surfaces, this invention designs a gradient cladding process with a low dilution rate at the bottom layer to ensure bonding and high hardness at the top layer to ensure wear resistance, and provides narrow-window process parameters optimized for 40Mn2 steel. The specialized powder formulation brings unexpected resistance to impact abrasive wear. The narrowed powder composition (especially the content of C, Cr, and B) of this invention, after gradient processing and post-treatment, can generate in-situ dispersed M7C3 and M... 23C6 type carbides are uniformly distributed on a fine-grained martensite matrix with a small amount of retained austenite. This microstructure exhibits excellent resistance to spalling and scratching under combined working conditions of high-stress impact and abrasive particles.

[0036] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for remanufacturing and strengthening excavator drive wheels based on laser cladding, characterized in that: Includes the following steps: Step 1: Pre-treatment and contouring of the drive wheels The worn excavator drive wheel is cleaned and inspected; firstly, the worn tooth surface of the drive wheel is machined to remove the fatigue layer, and then the worn area is machined into a contour repair groove with a smooth transition bevel according to the original tooth profile design drawing of the drive wheel; Step 2: Selection of cladding powder The selected iron-based alloy powder has the following composition and mass percentage: C: 0.18-0.25%, Cr: 14.0-16.0%, Ni: 1.5-2.5%, Mo: 0.8-1.2%, Si: 0.8-1.0%, Mn: 0.4-0.6%, B: 1.0-1.3%, with the balance being Fe; Step 3: Gradient laser cladding under conformal cooling Step 31: Using a synchronous powder feeding method, laser multi-layer cladding is performed on the pretreated drive wheel tooth surface under inert gas protection; During the cladding process, the conformal cooling fixture is tightly fitted to the drive wheel tooth groove and the side of the wheel body. The conformal cooling fixture consists of two opposing copper alloy pressure blocks. The working surfaces of the two pressure blocks are adapted to the shape of the drive wheel tooth groove, tooth side and the side of the wheel body. The pressure blocks are equipped with circulating water channels. Along the scanning direction, a dual-color infrared thermometer is fixedly installed behind the laser cladding head. The probe optical path of the dual-color infrared thermometer is aligned with the surface of the cladding layer or the substrate area adjacent to the surface of the cladding layer. The output signal of the infrared thermometer is transmitted to the PLC or industrial control computer in real time and linked with the electromagnetic regulating valve on the cooling water circulation system to form a closed-loop temperature control. Step 32: The laser cladding is a multi-layer cladding process using a gradient technique. For the bottom layer cladding, a laser power of 2200-2600W is used, the scanning speed is 10-15mm / s, the single layer thickness is 0.3-0.5mm, and 1-2 layers are clad to obtain a metallurgical bonding interface with a dilution rate of ≤8%. The intermediate and top layers are clad, and 2-4 more layers are clad on top of the bottom layer. The laser power is 3000-3500W, the scanning speed is 5-8mm / s, and the thickness of a single layer is 0.5-0.8mm to obtain a reinforced layer with high hardness and high wear resistance. Step 4: Post-processing and finishing The clad drive wheel is subjected to stress-relief annealing and heat preservation, then cooled in the furnace. The tooth profile is then ground according to the design drawings to accurately restore the tooth profile, tooth pitch and surface roughness. Finally, the repaired tooth surface is subjected to magnetic particle or dye penetrant testing.

2. The method for remanufacturing and strengthening excavator drive wheels based on laser cladding according to claim 1, characterized in that: The angle between the smooth bevel and the horizontal line in step 1 is 15-30°.

3. The method for remanufacturing and strengthening excavator drive wheels based on laser cladding according to claim 1, characterized in that: In step 1, the bottom of the contour repair groove is reserved with a cladding allowance of 0.3 mm to 0.5 mm.

4. The method for remanufacturing and strengthening excavator drive wheels based on laser cladding according to claim 1, characterized in that: In step 31, the conformal cooling fixture is connected to the drive wheel via a quick-change clamp or bolt tightening mechanism.

5. The method for remanufacturing and strengthening excavator drive wheels based on laser cladding according to claim 1, characterized in that: In step 31, the working surfaces of the two pressure blocks are precisely machined according to the contours of the drive wheel tooth groove, tooth side and wheel body side to form a mating surface that is compatible with and complementary to the concave and convex shapes of the drive wheel tooth groove, tooth side and wheel body side. The inlet and outlet of the circulating water channel are connected in parallel to the external cooling water circulation system via flexible hoses.

6. The method for remanufacturing and strengthening excavator drive wheels based on laser cladding according to claim 1, characterized in that: In step 31, when the dual-color infrared thermometer detects that the substrate temperature exceeds 200°C or the interlayer temperature exceeds 150°C, it automatically increases the cooling water flow rate or reduces the laser power / scanning speed.

7. The method for remanufacturing and strengthening excavator drive wheels based on laser cladding according to claim 1, characterized in that: In step 1, the powder particle size is 45-105μm.

8. The method for remanufacturing and strengthening excavator drive wheels based on laser cladding according to claim 1, characterized in that: In step 3, the overall process parameters of laser cladding are: spot diameter 3-5mm, overlap rate 40-50%, powder feeding amount 15-20g / min. Through multi-layer cladding, the dimensions of the worn part of the drive wheel are restored to the design dimension negative tolerance and a processing allowance of 0.2-0.3mm is reserved.

9. A method for remanufacturing and strengthening excavator drive wheels based on laser cladding according to claim 1, characterized in that: In step 3, a dual-color infrared thermometer is fixedly installed 50-80mm behind the laser cladding head along the scanning direction.

10. A method for remanufacturing and strengthening excavator drive wheels based on laser cladding according to claim 1, characterized in that: In step 4, the clad drive wheel is subjected to stress-relief annealing treatment, and then kept at 480-520℃ for 1-2 hours.

Images