Laser cladding process for hard alloy layer of blade

Abstract

The invention discloses a laser cladding process for a blade hard alloy layer, which comprises the following steps: S1, after obtaining a to-be-repaired gas turbine blade, detecting the components of the alloy layer to confirm the manufacturing material and the repairing material of the blade; s2, obtaining a microstructure of a to-be-repaired test piece, and carrying out laser cladding process confirmation on the to-be-repaired gas turbine blade; s3, designing a clamping tool of the blade; s4, setting a laser cladding original point and generating a program; s5, the gas turbine blade is repaired through a laser cladding robot; s6, detection and stress relief annealing are carried out after laser cladding; s7, the blade contact surface size is recovered through machining; s8, blade performance recovery heat treatment is conducted; according to the equipment in the process, three blades are continuously repaired at a time through linkage of the six-axis robot and the position changing machine, the equipment is more efficient, mechanical properties and use of the blades are not affected, high hardness is obtained by adopting the mixed cobalt-based hard alloy powder, meanwhile, thermal stress and structural stress generated during solidification are reduced, and cracking is avoided.

Description

Technical Field

[0001] The invention relates to a laser cladding process for a blade hard alloy layer, in particular to a laser cladding process. Background Art

[0002] Gas turbine blades (hereinafter referred to as "blades") are crucial components of gas turbine engines, and their design and manufacturing significantly impact the overall performance of the engine. To more effectively improve the overall structural strength and fatigue resistance of blades, a crown-like structure is sometimes added to the top of the blades to connect adjacent blades, forming a single unit. This disperses the stress and vibration experienced by the blades during operation, allowing the turbine engine to withstand greater strength and loads.

[0003] Gas turbine blades are subject to intense compression and thermal corrosion under high temperature and pressure, especially at the contact surface of the blade crown. To improve the high-temperature performance, friction and wear resistance, and corrosion resistance of the contact surface, a layer of cemented carbide is welded to the contact surface with argon arc welding.

[0004] When the blade completes a cycle of service (generally 20,000 to 30,000 hours), the carbide layer on the contact surface of the crown structure is worn, and the connection between the blades is no longer tight, so the carbide layer needs to be restored.

[0005] Restoring the carbide layer typically involves argon arc welding or thermal spraying, each with its own advantages and disadvantages. Argon arc welding has lower requirements for the site environment, and the weld is well-formed with fewer defects. However, since the blade contact surface has already been argon arc welded once, re-welding will expand the heat-affected zone of the blade base material, resulting in coarse grains in the base material contact surface structure and reduced performance. Furthermore, the structure near the blade crown contact surface is complex, and the airflow from the argon arc welding gun nozzle is relatively dispersed, resulting in poor shielding gas coverage during welding. Specific tooling is required to prevent the shielding gas from dispersing, causing significant inconvenience for the welder and reducing work efficiency. While thermal spraying can address the problem of expanding the heat-affected zone, the coating is relatively fragile and lacks precision. When the coating is too thick, machining equipment can cause it to flake off. Summary of the Invention

[0006] The present invention provides a laser cladding process for a blade carbide layer, which is used to overcome the defects of insufficient repair efficiency of a combustion engine blade and poor repair effect of the carbide layer in the prior art.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0008] The present invention discloses a laser cladding process for a blade cemented carbide layer, comprising the following steps:

[0009] S1. Detect the contact surface composition of the gas turbine blade to be repaired and confirm the manufacturing material of the blade;

[0010] S2. Use cobalt-chromium-molybdenum cemented carbide powder to clad the cemented carbide layer on the same substrate as the parent material, and confirm the compatibility of the repair process by observing the microstructure;

[0011] S3. Design the blade clamping fixture;

[0012] S4. Import the blade 3D digital model into the robot, set the model's coordinate system origin and the repair trajectory starting point through the control panel, and generate a program to locate the repair trajectory through the slicing software;

[0013] S5, starting the processing equipment and cladding the hard alloy layer on the blade contact surface according to the set trajectory;

[0014] S6. Performing nondestructive testing on the blade after cladding;

[0015] S7. Performing machining to restore the blade to its original size after nondestructive testing;

[0016] S8. Performing a heat treatment on the blade after machining to restore its performance;

[0017] The processing equipment includes a six-axis robot, which is respectively provided with axis A, axis B, axis C, axis D, axis E, axis F and a robotic arm. The robotic arm is provided with a laser cladding nozzle, and a base is provided below the laser cladding nozzle. A servo control system is integrated in the base and is linked with the six axes. A rotary positioner is provided above the base, and a positioner workbench is provided above the rotary positioner. Three groups of blade tooling for clamping blades are sequentially provided on the positioner workbench, and the rotary positioner includes an xy plane rotation axis and an xz plane rotation axis.

[0018] Furthermore, in step S1, a portable component analyzer is used to detect the leaf components. If necessary, samples can be taken from the contact surface and the leaf components can be confirmed using a scanning electron microscope.

[0019] Furthermore, when observing the microstructure in step S2, it is necessary to observe the heat-affected zone and the joint line. There should be no pores, cracks or unfused defects exceeding the size specified in the relevant technical agreement at the joint. After the defects are determined to be qualified, the reliability is verified through hardness or friction and wear tests, and finally a process feasibility verification report is formed.

[0020] Furthermore, the composition of the cobalt-chromium-molybdenum cemented carbide powder includes 0.90-1.40% C, 22.00-24.00% Cr, ≤3.00% Ni, 8.00-10.00% Mo, ≤3.00% Fe, ≤0.5% Mn, 1.50-3.50% W and 0.8-1.5% Si, and the rest is Co. The minimum hardness is 530HV and the maximum hardness can reach 600HV, which meets the performance requirements of the blade contact surface.

[0021] Furthermore, the tooling design in step S3 should be able to ensure that the tooling can be used for multiple purposes and can be used for origin positioning during repair, origin positioning for inspection dimensions, and origin positioning for machining and clamping.

[0022] Furthermore, the trajectory model of the slice in step S4 is drawn by a technician to ensure that there is sufficient machining allowance after cladding or to import the 3D digital model of the blade 8 into the robot, set the origin of the model's coordinate system and the starting point of the repair trajectory through the control panel, and generate a program for positioning the repair trajectory through the slicing software; since there are two repair trajectories, trajectory programs need to be generated separately for the trajectories of different materials, numbered as program 1 and program 2.

[0023] Furthermore, in step S5, the process parameters of laser power, scanning speed, scanning spacing, powder feeding rate, and spot diameter should be strictly controlled; the protective gas should be turned on, and the gas flow rate should be 15L / min to 30L / min.

[0024] Furthermore, the non-destructive testing in step S6 should include fluorescence testing and radiographic testing. When performing penetrant testing, the appearance should be free of cracks and pores; when performing X-ray testing, the internal quality should be free of cracks, unfused areas, dense pores, and high-density inclusions. The remaining quality requirements should comply with the specified technical conditions and acceptance conditions.

[0025] Furthermore, when machining to restore the blade contact surface size in step S7, three-coordinate measurement should be used to check the position of the blade and the standard digital model before machining to ensure that the blade and the digital model basically coincide with each other in the set coordinate system; since the contact surface has been covered by the laser cladding layer, another reference surface should be selected on the blade to make the measurement result of the reference surface coincide with the model, with a deviation of no more than ±0.05mm, so that the contact surface is the same as the standard digital model after machining; the tool feed rate should be strictly controlled during machining to avoid overcutting or insufficient machining; after machining, it should be measured again on the machine to ensure that after the blade contact surface is restored to size, the deviation from the digital model is ±0.1mm.

[0026] Furthermore, when performing the performance recovery treatment in step S8, the process parameters of vacuum degree, temperature, holding time and cooling method are strictly controlled; under the condition that the vacuum degree P value is less than 10Pa, it is heated from room temperature to a suitable temperature at a specific heating rate, and after the holding is completed, 1000-1500mbar argon is filled for rapid cooling, and the furnace temperature is reduced to room temperature. The vacuum pressure should be less than 5×10-2Pa when heating to above 500℃, during the holding process and before filling with argon; the blade body material is used in a cast state and there is no heat treatment process, so it should be ensured that the stress relief annealing process of the cemented carbide layer does not damage the blade body.

[0027] Furthermore, the six-axis robot is integrated with a double-barrel powder feeder, which switches the powder barrels through external control. First, powder barrel No. 1 is enabled, program 1 is enabled, and the three blades are repaired in sequence from No. 1 to No. 3: high-temperature alloy powder is used to first repair the interlocking surface on the blade basin side, and then the interlocking surface on the back of the blade is repaired by flipping the positioner; when all the interlocking surfaces are repaired, the avoidance surface on the blade basin side is flipped and repaired by the positioner, and then the avoidance surface on the back of the blade is flipped and repaired, and the order of No. 1 to No. 3 is still followed during the repair; when the high-temperature alloy material powder repair is completed, the powder barrel number is switched to powder barrel No. 2 through the external control interface, and program 2 is enabled, and the interlocking surfaces of the three blades are repaired in sequence with carbide powder in the order of No. 1 to No. 3. When all the interlocking surfaces are repaired, the avoidance surfaces are flipped and repaired in sequence by the positioner.

[0028] The beneficial effects achieved by the present invention are as follows: the equipment involved in this process is linked by a six-axis robot and a positioner to realize uninterrupted one-time repair of three blades. It only takes 2 to 5 minutes to repair a blade using this process, and there is no need for manual turning over, which is faster and more efficient, and does not affect the mechanical properties and normal use of the blade; the use of mixed cobalt-based cemented carbide powder reduces the thermal stress and tissue stress generated during solidification while achieving higher hardness, thereby avoiding cracking; since laser cladding is accompanied by simultaneous powder feeding, the gas concentration is high, eliminating the welding shielding gas tooling required for argon arc welding, and effectively avoiding oxidation; the digital model and physical part fitting method are used to find the reference plane, thereby improving the machining accuracy; a dual powder barrel powder feeding system is used, which can conveniently repair rotor blades that require two repair materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0030] Figure 1 It is a heat treatment detection diagram of the present invention;

[0031] Figure 2 It is a structural diagram of the device of the present invention;

[0032] Figure 3 It is a structural schematic diagram of the blade of the present invention.

[0033] In the figure: 1. Axis A; 2. Axis B; 3. Axis C; 4. Axis D; 5. Axis E; 6. Axis F; 7. Laser cladding nozzle; 8. Blade; 8-1. Blade basin; 8-2. Air avoidance surface; 8-3. Interlocking surface; 8-4. Blade back; 9. Blade tooling; 10. Positioner worktable; 11. Rotary positioner; 11-1. XY plane rotation axis; 11-2. XZ plane rotation axis; 12. Base; 13. Six-axis robot. DETAILED DESCRIPTION

[0034] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0035] Example 1

[0036] like Figures 1-2 As shown, a laser cladding process for a blade carbide layer to repair an interlocking surface and another interlocking surface of the blade includes the following steps:

[0037] S1. Detect the contact surface composition of the gas turbine blade to be repaired and confirm the manufacturing material of the blade;

[0038] S2. Use cobalt-chromium-molybdenum cemented carbide powder to clad the cemented carbide layer on the same substrate as the parent material, and confirm the compatibility of the repair process by observing the microstructure;

[0039] S3. Design the blade clamping fixture;

[0040] S4. Import the blade 3D digital model into the robot, set the model's coordinate system origin and the repair trajectory starting point through the control panel, and generate a program to locate the repair trajectory through the slicing software;

[0041] S5, starting the processing equipment and cladding the hard alloy layer on the blade contact surface according to the set trajectory;

[0042] S6. Performing nondestructive testing on the blade after cladding;

[0043] S7. Performing machining to restore the blade to its original size after nondestructive testing;

[0044] S8. Perform heat treatment on the blades after machining to restore their performance.

[0045] In step S1, a portable component analyzer is used to detect the leaf components. If necessary, samples can be taken from the contact surface and the leaf components can be confirmed by scanning electron microscopy;

[0046] When observing the microstructure in step S2, it is necessary to observe the heat-affected zone and the joint line. There should be no defects such as pores, cracks, and lack of fusion that exceed the size specified in the relevant technical agreement at the joint. After the defects are determined to be qualified, the reliability is verified through hardness or friction and wear tests, and finally a process feasibility verification report is generated;

[0047] The cobalt-chromium-molybdenum cemented carbide powder described in step S2 is formed by mixing two cobalt-based alloy powders. This powder can achieve high hardness while reducing thermal stress and structural stress generated during solidification, thereby preventing cracking. The powder is well metallurgically bonded to the matrix, with no defects such as pores, cracks, or lack of fusion. The minimum hardness is 530 HV and the maximum hardness can reach 600 HV, meeting the performance requirements of the blade contact surface.

[0048] Table 1 Chemical composition of Co-Cr-Mo cobalt-based alloy

[0049]

[0050] The tooling design in step S3 should ensure that the tooling can be used for multiple purposes, and can be used for origin positioning during repair, origin positioning for inspection dimensions, and origin positioning for machining and clamping;

[0051] The trajectory model of the slice in step S4 should be drawn by a technician to ensure that there is sufficient machining allowance after cladding;

[0052] In step S5, the process parameters of laser power, scanning speed, scanning spacing, powder feeding rate, and spot diameter should be strictly controlled; the protective gas should be turned on and the gas flow rate should be 15L / min to 30L / min;

[0053] The non-destructive testing in step S6 should include fluorescence testing and radiographic testing. When conducting penetrant testing, the exterior should be free of cracks and pores. When conducting X-ray testing, the internal quality should be free of cracks, lack of fusion, dense pores, and high-density inclusions. Other quality requirements should meet the specified technical conditions and acceptance criteria.

[0054] In step S7, when machining to restore the blade contact surface size, the position of the blade and the digital model should be measured on the machine before machining to ensure that the blade and the digital model basically coincide with each other in the set coordinate system; since the contact surface has been covered by the laser cladding layer, another reference surface should be selected on the blade to make the measurement result of the reference surface coincide with the model, with a deviation of no more than ±0.05mm, so that the contact surface is the same as the standard digital model after machining; the tool feed rate should be strictly controlled during machining to avoid overcutting or insufficient machining; after machining, it should be measured again on the machine to ensure that the deviation of the blade contact surface from the digital model is ±0.1mm after the size is restored;

[0055] During the performance recovery process in step S8, the process parameters of vacuum, temperature, holding time, and cooling method are strictly controlled; under the condition of vacuum P value less than 10Pa, the furnace is heated from room temperature to the appropriate temperature at a specific heating rate. After the holding period, 1000-1500mbar argon gas is filled for rapid cooling, and the furnace temperature is reduced to room temperature. The vacuum pressure should be less than 5×10 -2 Pa; The blade body material is used in the cast state without heat treatment process, so it should be ensured that the stress relief annealing process of the cemented carbide layer does not damage the blade body.

[0056] The processing equipment includes a six-axis robot 13, which is provided with an axis A1, an axis B2, an axis C3, an axis D4, an axis E5, an axis F6 and a robotic arm. The robotic arm is provided with a laser cladding nozzle 7. A base 12 is provided below the laser cladding nozzle 7. The base 12 is integrated with a servo control system and is linked with the six axes. A rotary positioner 11 is provided above the base 12. A positioner workbench 10 is provided above the rotary positioner 11. Three groups of blade tooling 9 for clamping blades 8 are sequentially provided on the positioner workbench 10. The rotary positioner 11 includes an xy plane rotation axis 11-1 and an xz plane rotation axis 11-2.

[0057] Working process: Figure 2 As shown, the equipment includes a six-axis robot 13, a clamping fixture 9 and a positioner workbench 10, and the base 12 is installed with a servo control system integrated with the six-axis linkage; the six-axis robot's axis A1, axis B2, axis C3, axis D4, axis E5 and axis F6 are completed together with the positioner workbench 10 and the rotary positioner 11, wherein the xy plane rotation axis 11-1 controls the xy plane rotation of the workbench surface, and the xz plane rotation axis 11-2 controls the xz plane rotation of the workbench surface; the positioner workbench is installed with three fixtures of the same model, and the set program is run. Under the linkage of the six axes and the positioner, the rotary positioner When the positioner 11 rotates, under the action of the xy plane rotation axis 11-1 and the xz plane rotation axis 11-2, the positioner workbench 10 drives the tooling and the blade to the xz plane, and the blade surface to be repaired is transferred to the xy plane through the xy plane rotation axis 11-1. The six-axis robot 13 controls the robotic arm to simultaneously move the laser cladding nozzle 7 to the position where the blade 8 needs to be repaired. The three blades are repaired in sequence from No. 1 to No. 3. The interlocking surface is repaired first. After all the interlocking surfaces of the blades are repaired, the other interlocking surface is repaired by flipping it over through the positioner, and the process is still carried out in sequence from No. 1 to No. 3.

[0058] Example 2

[0059] Blade 8 is a dual material repair blade, such as Figure 3 As shown, the air-avoiding surface 8-2 is made of a different material from the interlocking surface 8-3, so step S4 and step S5 are different.

[0060] The working process of step S4 is: import the 3D digital model of the blade 8 into the robot, set the model's coordinate system origin and the starting point of the repair trajectory through the control panel, and generate a program for positioning the repair trajectory through the slicing software; since there are two repair trajectories, it is necessary to generate trajectory programs for different materials separately, numbered as program 1 and program 2.

[0061] The working process of step S5 is:

[0062] like Figure 2 As shown, the equipment includes a six-axis robot 13, a clamping tool 9 and a positioner workbench 10, and the base 12 is installed with a servo control system integrated with the six-axis linkage; the axis A1, axis B2, axis C3, axis D4, axis E5 and axis F6 of the six-axis robot 13 are completed together with the positioner workbench 10 and the rotary positioner 11, wherein the xy plane rotation axis 11-1 controls the xy plane rotation of the workbench surface, and the xz plane rotation axis 11-2 controls the xz plane rotation of the workbench surface; the positioner workbench is installed with three toolings of the same model, and runs the set program. Under the linkage of the six-axis and the positioner, when the rotary positioner 11 rotates, under the action of the xy plane rotation axis 11-1 and the xz plane rotation axis 11-2, the positioner workbench 10 drives the tooling and the blade to the xz plane, and the surface of the blade to be repaired is transferred to the xy plane through the xy plane rotation axis 11-1, and the six-axis robot 13 controls the robotic arm to simultaneously move the laser cladding nozzle 7 to the position where the blade 8 needs to be repaired.

[0063] Two powder drums are required to repair the blade 8. The six-axis robot 13 is integrated with a dual-drum powder feeder, and the powder drums can be switched by external control. First, activate powder cartridge No. 1 and program 1, and repair the three blades 8 in sequence from No. 1 to No. 3: use a high-temperature alloy powder to first repair the interlocking surface 8-3 on the blade basin 8-1 side, and then use the positioner to flip and repair the interlocking surface 8-3 on the blade back 8-4 side; when all the interlocking surfaces 8-3 are repaired, flip and repair the air avoidance surface 8-2 on the blade basin 8-1 side through the positioner, and then flip and repair the air avoidance surface 8-2 on the blade back 8-4 side through the positioner, and the repair is still in the order of No. 1 to No. 3; when the high-temperature alloy material powder repair is completed, switch the powder cartridge number to powder cartridge No. 2 through the external control interface, and then activate program 2, and use cemented carbide powder to repair the interlocking surfaces 8-3 of the three blades 8 in sequence from No. 1 to No. 3. When all the interlocking surfaces 8-3 are repaired, flip and repair the air avoidance surface 8-2 in sequence through the positioner.

[0064] It should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will appreciate that they may modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, improvements, and the like that fall within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention. The terms used in the description of this application are intended only to describe specific embodiments and are not intended to limit the exemplary embodiments of the present invention. For ease of description, the dimensions of the various parts shown in the drawings are not drawn to scale. Technologies, methods, and devices known to persons skilled in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely illustrative and not limiting. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar reference numerals and letters denote similar items in the following figures. Therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0065] It should be noted that the terms "first," "second," etc. in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way are interchangeable where appropriate, so that the embodiments of this application can be implemented in an order other than those illustrated or described herein, and that the objects distinguished by "first," "second," etc. are generally of the same type, and do not limit the number of objects. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0066] It should be noted that, in the description of this application, the directions or positional relationships indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description. Unless otherwise specified, these directional terms do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of this application; the directional terms "inside and outside" refer to the inside and outside relative to the outline of each component itself.

Claims

1. A laser cladding process for blade carbide layer, characterized in that: The steps include: S1. Detect the contact surface composition of the gas turbine blade to be repaired and confirm the manufacturing material of the blade; S2. Use cobalt-chromium-molybdenum cemented carbide powder to clad the cemented carbide layer on the same substrate as the parent material, and confirm the compatibility of the repair process by observing the microstructure; S3. Design the blade clamping fixture; S4. Import the blade 3D digital model into the robot, set the model's coordinate system origin and the repair trajectory starting point through the control panel, and generate a program to locate the repair trajectory through the slicing software; S5, starting the processing equipment and cladding the hard alloy layer on the blade contact surface according to the set trajectory; S6. Performing nondestructive testing on the blade after cladding; S7. Performing machining to restore the blade to its original size after nondestructive testing; S8. Performing a heat treatment on the blade after machining to restore its performance; The processing equipment includes a six-axis robot, which is respectively provided with axis A, axis B, axis C, axis D, axis E, axis F and a robotic arm. The robotic arm is provided with a laser cladding nozzle, and a base is provided below the laser cladding nozzle. A servo control system is integrated in the base and is linked with the six axes. A rotary positioner is provided above the base, and a positioner workbench is provided above the rotary positioner. Three groups of blade tooling for clamping blades are sequentially provided on the positioner workbench, and the rotary positioner includes an xy plane rotation axis and an xz plane rotation axis.

2. The laser cladding process for blade carbide layer according to claim 1, characterized in that: In step S1, a portable component analyzer is used to detect the leaf components. If necessary, samples can be taken from the contact surface and the leaf components can be confirmed using a scanning electron microscope.

3. The laser cladding process for blade carbide layer according to claim 1, characterized in that: When observing the microstructure in step S2, it is necessary to observe the heat-affected zone and the joint line. There should be no pores, cracks or unfused defects exceeding the size specified in the relevant technical agreement at the joint. After the defects are determined to be qualified, the reliability is verified by hardness or friction and wear tests, and finally a process feasibility verification report is formed; The composition of the cobalt-chromium-molybdenum cemented carbide powder includes 0.90-1.40% C, 22.00-24.00% Cr, ≤3.00% Ni, 8.00-10.00% Mo, ≤3.00% Fe, ≤0.5% Mn, 1.50-3.50% W and 0.8-1.5% Si, and the rest is Co. The minimum hardness is 530HV and the maximum hardness can reach 600HV, which meets the performance requirements of the blade contact surface.

4. The laser cladding process for blade carbide layer according to claim 1, characterized in that: The tooling design in step S3 should be able to ensure that the tooling can be used for multiple purposes and can be used for origin positioning during repair, origin positioning for inspection dimensions, and origin positioning for machining and clamping.

5. The laser cladding process for blade carbide layer according to claim 1, characterized in that: The trajectory model of the slice in step S4 is drawn by a technician to ensure that there is sufficient machining allowance after cladding or to import the 3D digital model of the blade 8 into the robot. The coordinate system origin of the model and the starting point of the repair trajectory are set through the control panel, and the program for positioning the repair trajectory is generated through the slicing software; since there are two repair trajectories, trajectory programs need to be generated separately for the trajectories of different materials, numbered as program 1 and program 2.

6. The laser cladding process for blade carbide layer according to claim 1, characterized in that: In step S5, the process parameters of laser power, scanning speed, scanning spacing, powder feeding rate, and spot diameter should be strictly controlled; the protective gas should be turned on with a gas flow rate of 15 L / min to 30 L / min.

7. The laser cladding process for blade carbide layer according to claim 1, characterized in that: The non-destructive testing in step S6 should include fluorescence testing and radiographic testing. When performing penetrant testing, the appearance should be free of cracks and pores; when performing X-ray testing, the internal quality should be free of cracks, unfused parts, dense pores, and high-density inclusions. Other quality requirements should comply with the specified technical conditions and acceptance conditions.

8. The laser cladding process for blade carbide layer according to claim 1, characterized in that: When the blade contact surface size is restored by machining in step S7, three-coordinate measurement should be used to check the position of the blade and the standard digital model before machining to ensure that the blade and the digital model basically coincide with each other in the set coordinate system; since the contact surface has been covered by the laser cladding layer, another reference surface should be selected on the blade so that the measurement result of the reference surface coincides with the model, with a deviation not exceeding ±0.05mm, so that the contact surface is the same as the standard digital model after machining; the tool feed rate should be strictly controlled during machining to avoid overcutting or insufficient machining; after machining, it should be measured again on the machine to ensure that the deviation of the blade contact surface from the digital model is ±0.1mm after the size is restored.

9. The laser cladding process for blade carbide layer according to claim 1, characterized in that: During the performance recovery process in step S8, the process parameters of vacuum, temperature, holding time, and cooling method are strictly controlled; under the condition that the vacuum P value is less than 10Pa, the furnace is heated from room temperature to a suitable temperature at a specific heating rate. After the holding temperature is completed, 1000-1500mbar argon gas is filled for rapid cooling, and the furnace temperature is reduced to room temperature. When heating to above 500℃, the vacuum pressure during the holding process and before the argon filling should be less than 5×10 -2 Pa; The blade body material is used in the cast state without heat treatment process, so it should be ensured that the stress relief annealing process of the cemented carbide layer does not damage the blade body.

10. The laser cladding process for blade carbide layer according to claim 1, characterized in that: The six-axis robot is integrated with a double-barrel powder feeder, which switches the powder barrels through external control. First, powder barrel No. 1 is enabled, program 1 is enabled, and the three blades are repaired in sequence from No. 1 to No. 3: high-temperature alloy powder is used to first repair the interlocking surface on the blade basin side, and then the interlocking surface on the back side of the blade is repaired by flipping the positioner; when all the interlocking surfaces are repaired, the avoidance surface on the blade basin side is flipped and repaired by the positioner, and then the avoidance surface on the back side of the blade is flipped and repaired, and the repair is still in the order of No. 1 to No. 3; when the high-temperature alloy material powder repair is completed, the powder barrel number is switched to powder barrel No. 2 through the external control interface, and program 2 is enabled, and the interlocking surfaces of the three blades are repaired in sequence with cemented carbide powder in the order of No. 1 to No.

3. When all the interlocking surfaces are repaired, the avoidance surfaces are flipped and repaired in sequence by the positioner.

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