A method for high-speed laser cladding additive repair of 30CrMnSiNi2A ring clamps used in aviation

Abstract

This invention relates to the field of laser cladding additive repair technology, specifically a method for high-speed laser cladding additive repair of aerospace-grade 30CrMnSiNi2A ring clamps. The method includes: removing the phosphate layer from the outer surface of the clamp; grinding and cleaning the damaged area; determining high-speed laser cladding parameters; subsequently performing cladding repair on the damaged clamp; after repair, stress-relieving annealing on the ring clamp; restoring the clamp to its original dimensions using machining methods based on its original dimensions; and finally, phosphating the clamp to complete the repair. This invention provides a method for high-speed laser cladding additive repair of aerospace-grade 30CrMnSiNi2A ring clamps, enabling high-quality repair of 30CrMnSiNi2A ultra-high-strength alloy components. It facilitates repair work for testing and operational personnel and provides theoretical guidance and practical repair cases for the repair of related parts and accessories.

Description

Technical Field

[0001] This invention relates to the field of laser cladding additive repair technology, specifically a method for high-speed laser cladding additive repair of aerospace-grade 30CrMnSiNi2A ring clamps. Background Technology

[0002] Ring clamps made of 30CrMnSiNi2A ultra-high strength alloy steel are important components for fixing hydraulic rods in aircraft hydraulic actuation systems. To improve their corrosion resistance, the surface of the clamps is usually phosphated. Prolonged operation in harsh environments can lead to wear, scratches, and corrosion on some of the outer surfaces of the ring clamps, causing them to malfunction. Because aircraft-specific clamps have long manufacturing cycles and high costs, and replacement during maintenance is expensive, repairing damaged clamps can effectively reduce maintenance costs and shorten repair cycles.

[0003] High-speed laser cladding repair technology is a novel, low-thermal-damage, and high-efficiency repair technology developed from traditional laser cladding technology. This technology optimizes the cladding head of the powder delivery system, ensuring micro-melting of the substrate while achieving powder melting during flight. Because a small portion of the energy is used to melt the substrate during cladding, the thermal impact on the substrate is low, which is beneficial for high-quality, low-thermal-damage repair of components. 30CrMnSiNi2A is an ultra-high-strength alloy steel, requiring specialized research on its high-speed cladding repair forming and performance to provide theoretical guidance and practical repair cases for related components. Therefore, a method for high-speed laser cladding additive repair of aerospace-grade 30CrMnSiNi2A ring clamps is proposed. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a method for high-speed laser cladding additive repair of aerospace-grade 30CrMnSiNi2A ring clamps.

[0005] The technical problem to be solved by this invention is achieved by the following technical solution:

[0006] A method for high-speed laser cladding additive repair of aerospace-grade 30CrMnSiNi2A ring clamps includes the following steps:

[0007] (1) Measure the dimensions of the 30CrMnSiNi2A ring clamp, remove the phosphate layer on the outer surface of the 30CrMnSiNi2A ring clamp, grind and clean the damaged area, and measure the damage depth of the damaged area to determine the maximum damage depth.

[0008] (2) Select a set of parameters within the range of laser power 800-1200W, powder feeding speed 1-2 rpm, and rotation speed 60-120 rpm as the high-speed laser cladding process parameters. Substitute the high-speed laser cladding process parameters into the relationship between the single-pass cladding layer height, calculate the single-pass cladding layer height, and determine whether the single-pass cladding layer height is greater than 1.1 times the maximum damage depth. If it is satisfied, the set of parameters is determined as the high-speed laser cladding process parameters.

[0009] (3) Determine the width of the single-pass cladding layer based on the relationship between the high-speed laser cladding process parameters and the width of the single-pass cladding layer;

[0010] (4) Determine the laser scanning speed based on the determined width of the single cladding layer and the relationship between the width of the single cladding layer and the laser scanning speed;

[0011] (5) Determine the laser working time based on the determined laser scanning speed and the relationship between the laser scanning speed and the laser working time;

[0012] (6) Set the determined high-speed laser cladding process parameters, laser scanning speed, and laser working time in the high-speed laser cladding equipment, and perform high-speed laser cladding repair on the 30CrMnSiNi2A ring clamp.

[0013] (7) Stress-relieving annealing treatment was carried out on the 30CrMnSiNi2A ring clamp repaired by high-speed laser cladding.

[0014] (8) Based on the original dimensions of the 30CrMnSiNi2A annular clamp, the excess cladding layer on the surface of the 30CrMnSiNi2A annular clamp is removed by machining and restored to the original dimensions;

[0015] (9) The 30CrMnSiNi2A ring clamp was phosphated to complete the repair.

[0016] As a further improvement of the present invention, the dimensions of the 30CrMnSiNi2A annular clamp in step (1) include: an outer diameter of 40-80mm, a wall thickness of 10mm-15mm, and a width of 20-40mm.

[0017] As a further improvement of the present invention, in step (1), sandpaper with a grit of 1000 or higher is used for polishing, requiring the bottom of the damaged area to be flat and the sidewalls to be smoothly connected to the bottom. Alcohol or acetone is used for cleaning, and the damage depth of the damaged area is 1-130μm.

[0018] As a further improvement of the present invention, the relationship between the high-speed laser cladding process parameters and the height of the single-pass cladding layer in step (2) is as follows:

[0019] Single-pass cladding layer height = 0.03182 * laser power + 66.41133 * powder feeding speed - 0.58519 * rotation speed + 19.36406.

[0020] As a further improvement of the present invention, the relationship between the high-speed laser cladding process parameters and the width of the single-pass cladding layer in step (3) is as follows:

[0021] Single-pass cladding layer width = 0.36507 * laser power + 15.31433 * powder feeding speed - 6.06904 * rotation speed + 1006.06644.

[0022] As a further improvement of the present invention, the relationship between the width of the single-pass cladding layer and the laser scanning speed in step (4) is as follows:

[0023] Laser scanning speed = width of single cladding layer * rotation speed / 150.

[0024] As a further improvement of the present invention, the relationship between the laser scanning speed and the laser working time in step (5) is as follows:

[0025] Laser working time = clamp width / laser scanning speed.

[0026] As a further improvement of the present invention, the high-speed laser cladding process parameters in step (6) also include: the cladding powder is the same 30CrMnSiNi2A metal powder as the base material, the powder particle size is 20-53um, the powder feeding gas flow rate is 5L / min, the central protective gas flow rate is 10L / min, the powder spot diameter at the powder convergence point of the cladding head is 1mm-1.5mm, the laser spot diameter is 1mm-1.2mm, and during additive repair, the powder focus converges on the outer surface of the annular clamp.

[0027] As a further improvement of the present invention, the stress relief annealing process in step (7) is as follows: the 30CrMnSiNi2A ring clamp repaired by high-speed laser cladding is placed in an atmosphere furnace at 230-260℃ and kept for 2 hours. The protective atmosphere in the atmosphere furnace is argon or helium. After the heat preservation is completed, it is cooled with the furnace.

[0028] The beneficial effects of this invention are:

[0029] This invention provides a method for high-speed laser cladding additive repair of 30CrMnSiNi2A ring clamps used in aviation, which can achieve high-quality repair of 30CrMnSiNi2A ultra-high strength alloy parts, facilitate the repair work of testers and operators, and provide theoretical guidance and practical repair cases for the repair of related parts and accessories. Attached Figure Description

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0031] Figure 1 This is a schematic diagram of the morphology of the 30CrMnSiNi2A annular clamp in this invention;

[0032] Figure 2 This is a schematic diagram of the microstructure of the cladding layer after repair.

[0033] In the diagram: 1. Outer surface of the clamp. Detailed Implementation

[0034] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0035] The outer surface of a 30CrMnSiNi2A ultra-high strength alloy steel annular clamp in the hydraulic actuation system of a certain type of aircraft was damaged, with scratches penetrating the clamp surface. The outer diameter of the annular clamp ranges from 40mm to 60mm, the wall thickness from 10mm to 15mm, the width from 20mm to 40mm, and the maximum damage depth from 1mm to 130μm.

[0036] Example 1

[0037] In this embodiment, the outer diameter of the damaged annular clamp is 52mm, the wall thickness is 15mm, and the width is 25mm. A schematic diagram of the clamp's morphology is shown below. Figure 1 As shown.

[0038] A method for repairing aerospace-grade 30CrMnSiNi2A ring clamps using high-speed laser cladding additive manufacturing is presented, comprising the following steps:

[0039] (1) The outer surface of the clamp was polished with 1200-grit sandpaper to completely remove the phosphate layer. The damaged area was then polished to make the bottom of the damaged area flat and the sidewalls smoothly connected to the bottom. The maximum damage depth of the damaged area was measured to be 126 μm using a micrometer. The entire clamp to be repaired was cleaned with acetone to remove oil and impurities.

[0040] (2) The laser power of 1000W, the powder feeding speed of 2 rpm, and the rotation speed of 60 rpm were selected as the high-speed laser cladding process parameters. Substituting these parameters into the relationship between the high-speed laser cladding process parameters and the single-pass cladding layer height: Single-pass cladding layer height = 0.03182 * laser power + 66.41133 * powder feeding speed - 0.58519 * rotation speed + 19.36406; the calculated single-pass cladding layer height is 148.9μm, which is greater than 1.1 * 126; this set of parameters was determined as the high-speed laser cladding process parameters.

[0041] (3) Based on the relationship between the high-speed laser cladding process parameters and the width of a single cladding layer: width of a single cladding layer = 0.36507 * laser power + 15.31433 * powder feeding speed - 6.06904 * rotation speed + 1006.06644, the width of a single cladding layer is determined to be 1037.6 μm.

[0042] (4) Based on the determined width of the single cladding layer and the relationship between the width of the single cladding layer and the laser scanning speed: laser scanning speed = width of single cladding layer * rotation speed / 150, the laser scanning speed is determined to be 0.415 mm / s.

[0043] (5) Based on the determined laser scanning speed and the relationship between laser scanning speed and laser working time: laser working time = clamp width / laser scanning speed, the laser working time is determined to be 89.2s.

[0044] (6) Set the determined high-speed laser cladding process parameters, laser scanning speed, and laser working time in the high-speed laser cladding equipment. Then, the motor drives the 30CrMnSiNi2A ring clamp to rotate, and the laser powder beam moves on the outer surface of the 30CrMnSiNi2A ring clamp to complete the cladding according to the set parameters.

[0045] The high-speed laser cladding process parameters also include: the cladding powder is the same 30CrMnSiNi2A metal powder as the base material, with a powder particle size between 20-53µm. The powder feeding gas flow rate is 5L / min, the central protective gas flow rate is 10L / min, the powder spot diameter at the powder convergence point of the cladding head is in the range of 1mm-1.5mm, the laser spot diameter is in the range of 1mm-1.2mm, and during additive repair, the powder focus converges on the outer surface of the annular clamp.

[0046] The repaired clamp was tested, and the hardness of the substrate was 523.5 HV, while the hardness of the cladding layer was 549.7 HV. The hardness of the cladding layer after repair is higher than that of the substrate, meeting the requirements. The microstructure morphology of the repaired cladding layer is as follows. Figure 2 As shown.

[0047] (7) The 30CrMnSiNi2A ring clamp repaired by high-speed laser cladding is placed in an atmosphere furnace, heated to 230℃ and held for 2 hours. The protective atmosphere is argon. After the holding is completed, it is cooled with the furnace.

[0048] (8) Based on the original dimensions of the 30CrMnSiNi2A ring clamp, the excess cladding layer on the surface of the 30CrMnSiNi2A ring clamp is removed by machining and restored to the original dimensions.

[0049] (9) The 30CrMnSiNi2A ring clamp was phosphated to complete the repair.

[0050] Example 2

[0051] The difference from Example 1 is that...

[0052] The maximum damage depth of the damaged area was measured to be 94 μm using a micrometer. The high-speed laser cladding process parameters were selected as follows: laser power 800 W, powder feed speed 2 rpm, and rotation speed 120 rpm. The calculated single-pass cladding layer height was 107.4 μm, which is greater than 1.1 * 94. The determined single-pass cladding layer width was 600.5 μm, the laser scanning speed was 0.48 mm / s, and the laser working time was 52.1 s. The hardness of the repaired cladding layer was tested to be 553.5 HV, which is higher than the substrate hardness and meets the requirements.

[0053] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely prisms of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for high-speed laser cladding additive repair of aerospace-grade 30CrMnSiNi2A ring clamps, characterized in that: Includes the following steps: (1) Measure the dimensions of the 30CrMnSiNi2A ring clamp, remove the phosphate layer on the outer surface of the 30CrMnSiNi2A ring clamp, grind and clean the damaged area, and measure the damage depth of the damaged area to determine the maximum damage depth. (2) Select a set of parameters within the range of laser power 800-1200W, powder feeding speed 1-2 rpm, and rotation speed 60-120 rpm as the high-speed laser cladding process parameters. Substitute the high-speed laser cladding process parameters into the relationship between the single-pass cladding layer height, calculate the single-pass cladding layer height, and determine whether the single-pass cladding layer height is greater than 1.1 times the maximum damage depth. If it is satisfied, the set of parameters is determined as the high-speed laser cladding process parameters. (3) Determine the width of a single cladding layer based on the relationship between the high-speed laser cladding process parameters and the width of a single cladding layer; (4) Determine the laser scanning speed based on the determined width of the single cladding layer and the relationship between the width of the single cladding layer and the laser scanning speed; (5) Determine the laser working time based on the determined laser scanning speed and the relationship between the laser scanning speed and the laser working time; (6) Set the determined high-speed laser cladding process parameters, laser scanning speed and laser working time in the high-speed laser cladding equipment, and perform high-speed laser cladding repair on the 30CrMnSiNi2A ring clamp. The particle size of the powder used for cladding is 20-53um. (7) The 30CrMnSiNi2A ring clamp repaired by high-speed laser cladding is subjected to stress-relieving annealing treatment at a temperature of 230-260℃ and held for 2 hours. (8) Based on the original dimensions of the 30CrMnSiNi2A annular clamp, remove the excess cladding layer on the surface of the 30CrMnSiNi2A annular clamp by machining and restore it to its original dimensions; (9) The 30CrMnSiNi2A ring clamp was phosphated to complete the repair; The relationship between the high-speed laser cladding process parameters and the height of a single cladding layer in step (2) is as follows: The height of a single cladding layer = 0.03182 * laser power + 66.41133 * powder feeding speed - 0.58519 * rotation speed + 19.36406; the relationship between the high-speed laser cladding process parameters and the width of a single cladding layer in step (3) is as follows: The width of a single cladding layer = 0.36507 * laser power + 15.31433 * powder feeding speed - 6.06904 * rotation speed + 1006.06644; the relationship between the width of a single cladding layer and the laser scanning speed in step (4) is: Laser scanning speed = width of single-pass cladding layer * rotation speed / 150; the relationship between laser scanning speed and laser working time in step (5) is: Laser working time = clamp width / laser scanning speed; The hardness of the cladding layer is 549.7–553.5 HV.

2. The method for high-speed laser cladding additive repair of aerospace-grade 30CrMnSiNi2A ring clamps according to claim 1, characterized in that: In step (1), the dimensions of the 30CrMnSiNi2A annular clamp include: clamp outer diameter of 40-80mm, clamp wall thickness of 10mm-15mm, and clamp width of 20-40mm.

3. The method for high-speed laser cladding additive repair of aerospace-grade 30CrMnSiNi2A ring clamps according to claim 1, characterized in that: In step (1), sandpaper with a grit of 1000 or higher is used for polishing. The bottom of the damaged area should be flat and the sidewalls should be smoothly connected to the bottom. Alcohol or acetone should be used for cleaning. The depth of the damaged area is 1-130 μm.

4. The method for high-speed laser cladding additive repair of aerospace-grade 30CrMnSiNi2A ring clamps according to claim 1, characterized in that: The high-speed laser cladding process parameters in step (6) also include: the cladding powder is the same 30CrMnSiNi2A metal powder as the base material, the powder feeding gas flow rate is 5L / min, the central protective gas flow rate is 10L / min, the powder spot diameter at the powder convergence point of the cladding head is 1mm-1.5mm, the laser spot diameter is 1mm-1.2mm, and during additive repair, the powder focus converges on the outer surface of the annular clamp.

5. The method for high-speed laser cladding additive repair of aerospace-grade 30CrMnSiNi2A ring clamps according to claim 1, characterized in that: The stress-relief annealing process in step (7) is as follows: the 30CrMnSiNi2A ring clamp repaired by high-speed laser cladding is placed in an atmosphere furnace for heat preservation. The protective atmosphere in the atmosphere furnace is argon or helium. After heat preservation, it is cooled with the furnace.

Images