Method for repairing 30CrMnSiNi2A annular clamp for aviation through high-speed laser cladding additive

Abstract

The invention relates to the technical field of laser cladding additive repair, in particular to a method for repairing an aviation 30CrMnSiNi2A annular clamp through high-speed laser cladding additive, which comprises the following steps: removing a phosphate coating on the outer surface of the clamp, polishing and cleaning a damaged area, determining high-speed laser cladding parameters, and then carrying out cladding repair on the damaged clamp. And after repairing is completed, stress relief annealing is conducted on the annular clamp, according to the original size of the clamp, the clamp is restored to the original size through a machining method, finally, phosphating treatment is conducted on the clamp, and repairing is completed. According to the method for repairing the 30CrMnSiNi2A annular clamp for aviation through the high-speed laser cladding additive, high-quality repairing of the 30CrMnSiNi2A ultrahigh-strength alloy part can be achieved, repairing work of tests and operators is facilitated, and theoretical guidance and actual repairing cases are provided for repairing related accessories.

Description

Technical Field

[0001] The invention relates to the technical field of laser cladding additive repair, and in particular to a method for high-speed laser cladding additive repair of a 30CrMnSiNi2A annular clamp for aviation. Background Art

[0002] The ring clamp made of 30CrMnSiNi2A ultra-high strength alloy steel is an important accessory for fixing the hydraulic rod of the aircraft hydraulic actuation system. In order to improve its corrosion resistance, the surface of the clamp is usually phosphated. The ring clamp works in a harsh environment for a long time, causing wear, scratches, corrosion and other defects on part of the outer surface, making the clamp damaged. Since the production cycle and cost of aircraft-specific clamps are long and the cost of replacement is high during maintenance, repairing the damaged clamp can effectively reduce maintenance costs and reduce repair cycles.

[0003] High-speed laser cladding repair technology is a new type of low-heat damage and high-efficiency repair technology developed based on traditional laser cladding technology. This technology optimizes the cladding head of the powder feeding system, and realizes the melting of powder in flight while ensuring the micro-melting of the substrate. Since a small part of the energy in the cladding process is used to melt the substrate, the thermal impact on the substrate is low, which is conducive to high-quality, low-heat damage repair of parts and accessories. 30CrMnSiNi2A is an ultra-high-strength alloy steel, and its high-speed cladding repair forming and performance need to be studied specifically to provide theoretical guidance and practical repair cases for the repair of related parts and accessories. Therefore, a method for high-speed laser cladding additive repair of 30CrMnSiNi2A annular clamps for aviation is proposed. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes a method for high-speed laser cladding additive repair of 30CrMnSiNi2A annular clamp for aviation.

[0005] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0006] A method for repairing a 30CrMnSiNi2A annular clamp for aviation by high-speed laser cladding additive, comprising the following steps:

[0007] (1) Measure the size of the 30CrMnSiNi2A annular clamp, remove the phosphating layer on the outer surface of the 30CrMnSiNi2A annular clamp, polish and clean the damaged area, and measure the damage depth of the damaged area to determine the maximum damage depth;

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

[0009] (3) Determine the width of a single cladding layer according to the relationship between high-speed laser cladding process parameters and the width of a single cladding layer;

[0010] (4) determining the laser scanning speed according to the determined single-track cladding layer width and the relationship between the single-track cladding layer width and the laser scanning speed;

[0011] (5) determining the laser working time according to the determined laser scanning speed and the relationship between the laser scanning speed and the laser working time;

[0012] (6) The determined high-speed laser cladding process parameters, laser scanning speed, and laser working time are set in the high-speed laser cladding equipment, and the 30CrMnSiNi2A annular clamp is repaired by high-speed laser cladding;

[0013] (7) Stress relief annealing treatment is performed on the 30CrMnSiNi2A annular clamp repaired by high-speed laser cladding;

[0014] (8) According to the original size 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 size;

[0015] (9) Phosphate the 30CrMnSiNi2A ring clamp 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 the clamp is 40-80 mm, a wall thickness of the clamp is 10 mm-15 mm, and a width of the clamp is 20-40 mm.

[0017] As a further improvement of the present invention, in step (1), sandpaper with a mesh size of 1000 or above is used for polishing, the bottom of the damaged area is required to be flat and the side wall is smoothly connected to the bottom, and alcohol or acetone is used for cleaning, and the damage depth of the damaged area is 1-130 μm.

[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:

[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:

[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:

[0023] Laser scanning speed = single-pass cladding layer width * 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:

[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 30CrMnSiNi2A metal powder that is the same as the base material, the powder particle size is 20-53um, the powder feeding gas flow rate is 5L / mim, the center shielding 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: placing the 30CrMnSiNi2A annular clamp repaired by high-speed laser cladding in an atmosphere furnace at 230-260°C and keeping it warm for 2 hours, the protective atmosphere in the atmosphere furnace is argon or helium, and cooling with the furnace after the insulation is completed.

[0028] The beneficial effects of the present invention are:

[0029] The present invention provides a method for high-speed laser cladding additive repair of 30CrMnSiNi2A annular clamp for 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention is further described below in conjunction with the accompanying drawings and embodiments:

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

[0032] Figure 2 Schematic diagram of the microstructure of the cladding layer after repair.

[0033] In the figure: 1. Outer surface of the clamp. DETAILED DESCRIPTION

[0034] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with the accompanying drawings and embodiments.

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

[0036] Embodiment 1

[0037] In this embodiment, the outer diameter of the damaged annular clamp is 52 mm, the clamp wall thickness is 15 mm, and the width is 25 mm. The schematic diagram of the clamp morphology is shown in FIG. Figure 1 shown.

[0038] A method for repairing a 30CrMnSiNi2A annular clamp for aviation using high-speed laser cladding additive is used for repair, including the following steps:

[0039] (1) Use 1200-grit sandpaper to grind the outer surface of the clamp to completely remove the phosphate layer on the outer surface of the clamp, and then grind the damaged area to make the bottom of the damaged area flat and the side wall and the bottom smoothly connected. The maximum damage depth of the damaged area measured by a spiral micrometer is 126μm. Use acetone to clean the entire clamp to be repaired to remove oil and impurities.

[0040] (2) Select laser power 1000W, powder feeding speed 2 rpm, and rotation speed 60 rpm as high-speed laser cladding process parameters, and substitute the relationship between high-speed laser cladding process parameters and single-pass cladding layer height into the following equation: single-pass cladding layer height = 0.03182*laser power + 66.41133*powder feeding speed - 0.58519*rotation speed + 19.36406; the single-pass cladding layer height is calculated to be 148.9 μm, and 148.9 is greater than 1.1*126; this group of parameters is determined as the high-speed laser cladding process parameters.

[0041] (3) According to the relationship between the high-speed laser cladding process parameters and the width of a single cladding layer: single cladding layer width = 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) According to the determined single-track cladding layer width and the relationship between the single-track cladding layer width and the laser scanning speed: laser scanning speed = single-track cladding layer width * rotation speed / 150, the laser scanning speed is determined to be 0.415 mm / s.

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

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

[0045] High-speed laser cladding process parameters also include: the cladding powder uses the same 30CrMnSiNi2A metal powder as the parent material, and the powder particle size is between 20-53um. The powder feeding gas flow rate is 5L / min, the central shielding 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, and the laser spot diameter is in the range of 1mm-1.2mm. During additive repair, the powder focus is concentrated on the outer surface of the annular clamp.

[0046] The repaired clamp was tested and the substrate hardness was 523.5HV, the cladding layer hardness was 549.7HV. The hardness of the repaired cladding layer was higher than that of the substrate, which met the requirements. The microstructure of the repaired cladding layer is as follows: Figure 2 shown.

[0047] (7) The 30CrMnSiNi2A annular clamp repaired by high-speed laser cladding was placed in an atmosphere furnace, heated to 230°C and kept warm for 2 hours. The protective atmosphere was argon gas. After the insulation was completed, it was cooled with the furnace.

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

[0049] (9) Phosphate the 30CrMnSiNi2A ring clamp to complete the repair.

[0050] Embodiment 2

[0051] The difference from the first embodiment is that.

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

[0053] The above shows and describes 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 above embodiments and descriptions only describe the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for repairing 30CrMnSiNi2A annular clamp for aviation by high-speed laser cladding additive, characterized in that: The following steps are involved: (1) Measure the size of the 30CrMnSiNi2A annular clamp, remove the phosphating layer on the outer surface of the 30CrMnSiNi2A annular clamp, polish and clean the damaged area, and measure the damage depth of the damaged area to determine the maximum damage depth; (2) A set of parameters is selected as high-speed laser cladding process parameters within the range of laser power 800-1200 W, powder feeding speed 1-2 rpm, and rotation speed 60-120 rpm. The parameters are substituted into the relationship between the high-speed laser cladding process parameters and the height of a single-pass cladding layer to calculate the height of a single-pass cladding layer and determine whether the height of a single-pass cladding layer is greater than 1.1 times the maximum damage depth. If so, the set of parameters is determined as the high-speed laser cladding process parameters. (3) Determine the width of a single cladding layer according to the relationship between high-speed laser cladding process parameters and the width of a single cladding layer; (4) determining the laser scanning speed according to the determined single-track cladding layer width and the relationship between the single-track cladding layer width and the laser scanning speed; (5) determining the laser working time according to the determined laser scanning speed and the relationship between the laser scanning speed and the laser working time; (6) The determined high-speed laser cladding process parameters, laser scanning speed, and laser working time are set in the high-speed laser cladding equipment, and the 30CrMnSiNi2A annular clamp is repaired by high-speed laser cladding; (7) Stress relief annealing treatment is performed on the 30CrMnSiNi2A annular clamp repaired by high-speed laser cladding; (8) According to the original size 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 size; (9) Phosphate the 30CrMnSiNi2A ring clamp to complete the repair.

2. A method for repairing 30CrMnSiNi2A annular clamp for aviation by high-speed laser cladding additive according to claim 1, characterized in that: The dimensions of the 30CrMnSiNi2A annular clamp in step (1) include: an outer diameter of the clamp is 40-80 mm, a wall thickness of the clamp is 10 mm-15 mm, and a width of the clamp is 20-40 mm.

3. The method for repairing 30CrMnSiNi2A annular clamp for aviation by high-speed laser cladding additive according to claim 1, characterized in that: In step (1), sandpaper with a mesh size of 1000 or above is used for polishing. The bottom of the damaged area is required to be flat and the side wall is smoothly connected to the bottom. Alcohol or acetone is used for cleaning. The damage depth of the damaged area is 1-130 μm.

4. The method for repairing 30CrMnSiNi2A annular clamp for aviation by high-speed laser cladding additive according to claim 1, characterized in that: The relationship between the high-speed laser cladding process parameters and the height of the single-pass cladding layer in step (2) is: Single-pass cladding layer height = 0.03182*laser power + 66.41133*powder feeding speed - 0.58519*rotation speed + 19.36406.

5. The method for repairing 30CrMnSiNi2A annular clamp for aviation by high-speed laser cladding additive according to claim 1, characterized in that: The relationship between the high-speed laser cladding process parameters and the width of a single cladding layer in step (3) is: Single-pass cladding layer width = 0.36507*laser power + 15.31433*powder feeding speed - 6.06904*rotation speed + 1006.06644.

6. The method for repairing 30CrMnSiNi2A annular clamp for aviation by high-speed laser cladding additive according to claim 1, characterized in that: The relationship between the width of a single cladding layer and the laser scanning speed in step (4) is: Laser scanning speed = single-pass cladding layer width * rotation speed / 150.

7. The method for repairing 30CrMnSiNi2A annular clamp for aviation by high-speed laser cladding additive according to claim 1, characterized in that: The relationship between the laser scanning speed and the laser working time in step (5) is: Laser working time = clamp width / laser scanning speed.

8. The method for repairing 30CrMnSiNi2A annular clamp for aviation by high-speed laser cladding additive according to claim 1, characterized in that: The high-speed laser cladding process parameters in step (6) also include: the cladding powder is 30CrMnSiNi2A metal powder that is the same as the base material, the powder particle size is 20-53um, the powder feeding gas flow rate is 5L / mim, the center shielding 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.

9. The method for repairing 30CrMnSiNi2A annular clamp for aviation by high-speed laser cladding additive according to claim 1, characterized in that: The stress relief annealing process in step (7) is as follows: the 30CrMnSiNi2A annular clamp repaired by high-speed laser cladding is placed in an atmosphere furnace at 230-260°C and kept warm for 2 hours. The protective atmosphere in the atmosphere furnace is argon or helium. After the insulation is completed, it is cooled with the furnace.

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