An integral forming process for mounting support points of an aircraft engine

Abstract

The invention discloses an integral forming process for mounting a support point of an aero-engine, comprising the following steps: forging design: combining a support point body and a support point flange edge into a whole, and designing the forging size according to the processing allowance; blank preparation: calculating the maximum cross section of the forging and determining the blank specification; integral forming: placing the blank in a bending device after heating, and immediately placing it in a forming die for pre-forming after bending, and then heating it again after sand blowing and repairing, and placing it in the forming die again to complete the final forming; heat treatment: heating the forging in a vacuum furnace, and air cooling it after it is taken out of the furnace; physical and chemical testing: sampling and testing H content, macrostructure, microstructure and hardness; mechanical processing: processing the finished support point assembly according to the combined parts drawing; comprehensive inspection: physical and chemical testing of H content, macrostructure and microstructure again; geometric dimension detection; ultrasonic flaw detection. The invention improves the qualified rate of the finished support point, reduces the consumption of forging materials, and saves the cost of forging materials.

Description

Technical Field

[0001] The invention belongs to the technical field of aircraft engine parts processing, and in particular relates to an integral forming process for aircraft engine mounting support points. Background Art

[0002] Titanium alloy is a new type of metal structural material developed after World War II. Its main characteristics are low density and high strength. Low density and high strength make titanium alloy have high specific strength. At the same time, it has a series of advantages such as good heat resistance and corrosion resistance, good toughness and weldability. Therefore, titanium alloy has been successfully applied in aerospace, petrochemical, shipbuilding, automobile, medicine and other departments. Among them, the aviation industry is the main user of titanium alloy. According to statistics, 80% of titanium materials produced internationally are used in aviation systems. Secondly, due to its high corrosion resistance, it is widely used in pumps and pipelines in the chemical industry, as well as in food, pharmaceuticals, and biomaterials.

[0003] Titanium alloys were first used in aircraft engine structures, which can reduce the weight of engine rotor parts by 1kg and the weight of the entire engine by 3-5kg. Therefore, replacing part of aluminum alloy and alloy steel with titanium alloys in aircraft engines can reduce the weight of the engine by 100-500kg. In aircraft engines, titanium alloys are mainly used to manufacture compressor discs, blades and casings, mounting points and other parts.

[0004] Install the support point assembly (if attached Figure 3 As shown in the figure, it is an important engine component, made of TC4, and the acceptance requirements for forging blanks are Class III parts of GJB2744A standard. The original design of the support point assembly consists of the support point body (as shown in the figure). Figure 1 As shown), support point flange edge (as shown in the attached Figure 2 As shown in the figure, it is welded by specialized personnel due to high welding requirements. Once the operation is replaced, the welded parts will have certain problems and be scrapped (the scrap rate is about 30%). In addition, the welding process forgings consumes a lot of materials, and the welded parts are prone to welding quality problems (such as porosity, looseness, slag inclusion, deformation, misalignment, etc.), and the qualified rate of finished products is low, which is very unfavorable for mass production. Summary of the invention

[0005] The present invention aims to provide an integral forming process for mounting support points of an aero-engine, so as to solve the problem of low qualified rate of finished products of welding processing of existing support point components.

[0006] An integral forming process of an aircraft engine mounting support point in this scheme includes the following steps:

[0007] Step 1, forging design: combine the support point body and the support point flange edge into a whole, and design the forging size according to the processing allowance;

[0008] Step 2, blank preparation: according to the forging design requirements, calculate the maximum cross-section of the forging and determine the blank specifications;

[0009] Step 3, overall forming: After the blank is heated, it is placed in a bending device for bending, and immediately placed in a forming mold for pre-forming, and then sandblasted, repaired, and heated again, and placed in the forming mold again to complete the final forming;

[0010] Step 4, heat treatment: heat the forging to 800±10℃ in a vacuum furnace, keep it warm for 100±15min, and air cool it after it comes out of the furnace;

[0011] Step 5, physical and chemical testing: sampling and testing of H content, macrostructure, microstructure and hardness;

[0012] Step 6, machining: machining the finished support point assembly according to the assembled parts drawing;

[0013] Step 7, comprehensive inspection: physical and chemical testing of H content, macrostructure and microstructure again; geometric dimension testing; ultrasonic flaw detection.

[0014] Preferably, the blank preparation in step 2 includes the following processes: material procurement, blanking, coating, heating, cutting, testing, rough machining and flaw detection.

[0015] Preferably, the coating process refers to cleaning dirt and oil on the surface of the blank with salt water, heating it in an oven to 250-300°C after natural drying, then placing the blank in a paint bucket for dipping and coating, and then placing it on a turntable to dry, and placing the dried blank in an oven to heat it to 250-300°C.

[0016] Preferably, the heating process is to place the coated blank into a box-type resistance furnace and heat it to 940±10° C. and keep it warm for 60±10 minutes.

[0017] Preferably, in step three, the overall forming specifically includes the following processes: one glass coating, one heating, one bending, preforming, one sand blasting, one repair, two glass coatings, two heatings, final forming, two sand blastings and two repairs.

[0018] Preferably, the preforming process refers to clamping the bent blank into a forming die on a 2500T electric screw press within 5 seconds for forming.

[0019] The beneficial effects of the present invention are as follows: the support point integral forging involved in the present invention is a whole-piece forging of the support point body and the support point flange edge. Since the welding scheme has a high scrap rate due to welding skills, the blank is processed after being integrally formed through technological innovation, which solves the existing problems in welding, improves the qualified rate of the support point finished product (98%), reduces the consumption of forging materials, saves the cost of forging materials, meets the design requirements, and improves the economic benefits of the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of a support point body for installing a support point in the prior art;

[0021] Figure 2 It is a structural schematic diagram of the flange edge of the support point for installing the support point in the prior art;

[0022] Figure 3 It is a structural schematic diagram of the mounting support point of the aircraft engine in the present invention;

[0023] Figure 4 The overall forging diagram of the mounting support point of the aircraft engine in the present invention;

[0024] Figure 5 It is a die forging drawing diagram of the mounting support point of the aircraft engine in the present invention;

[0025] Figure 6 This is a blank bending diagram of the mounting support point of the aircraft engine in the present invention. DETAILED DESCRIPTION

[0026] The following is further described in detail through specific implementation methods:

[0027] Embodiment 1: A process for integrally forming an aircraft engine mounting support point, comprising the following steps:

[0028] Step 1, forging design: combine the support point body and the support point flange into a whole, design the forging size according to the processing allowance, and consider that the installation support point forging needs flaw detection and increase the thickness direction allowance. Figure 4 shown.

[0029] Step 2, blank preparation: The first step is material procurement and re-inspection. Purchase φ70 specification bars according to GJB2218A standard. After entering the factory, re-inspect the chemical composition, mechanical properties, macrostructure, microstructure, and ultrasonic flaw detection (according to GB / T5193 standard A-level acceptance);

[0030] The second step is cutting: (1) Cut the material into φ70×460 using a saw; (2) Chamfer the corners R3~R5 (at both ends) on a lathe;

[0031] The third step is coating treatment, (1) clean the dirt and oil on the surface of the blank with salt water; (2) dry naturally and then heat it in an oven to 250-300°C; (3) coating, 1) put the blank into a paint bucket and dip it, then put it on a special turntable to dry, or use a non-linting brush to evenly coat it and put it on a special turntable to dry; 2) check whether the coating is uniform, and re-coat if there is any peeling or unevenness; 3) put the dried blank into an oven and heat it to 250-300°C;

[0032] The fourth step is heating. The coated blank is placed in a box-type resistance furnace and heated to 940±10℃ for 60±10min.

[0033] The fifth step is to pull the feet. Pull the feet (at both ends) on a 560kg air hammer. Figure 5 As shown;

[0034] The sixth step is testing. Cut off the full heads at both ends of the blank and use the full heads to conduct macroscopic and microscopic inspections. After meeting the requirements of GJB2744A, proceed with subsequent production.

[0035] The seventh step is rough machining, which is done by using a lathe;

[0036] The eighth step is flaw detection, and ultrasonic flaw detection is performed according to GJB2744A standard Class A.

[0037] Step 3, tooling preparation: Prepare tooling according to the forging design to facilitate processing. The tooling includes bending tooling, forming tooling, and trimming tooling, which need to be debugged and qualified.

[0038] Step 4, overall forming: Step 1, one-time glass coating: apply glass coating to the blank; Step 2, one-time heating: put the blank coated with glass coating into a box-type resistance furnace and heat it to 940±10℃, and keep it warm for 60±10min; Step 3, bending: put the heated blank into the bending die on the 1600T friction press and bend it. Figure 6 As shown; the fourth step, preforming: the bent blank is quickly (controlled within 5 seconds) clamped to the forming die on the 2500T electric screw press for forming; the fifth step, the first sand blasting: the preformed blank is placed in the sand blasting machine for sand blasting; the sixth step, the first repair: the surface defects of the blank are polished with a portable grinding wheel, and the defects are checked by fluorescent penetration after pickling to see if they are cleaned up; the seventh step, the second coating of glass paint: the blank is coated with glass paint again; the eighth step, the second heating: the coated blank is placed in a box-type resistance furnace and heated to 940±10℃, and kept warm for 30±10min; the ninth step, the final forming: the heated blank is quickly clamped to the forming die on the 2500T electric screw press for final forming; the tenth step, the second sand blasting: the final formed blank is placed in the sand blasting machine for sand blasting; the eleventh step, the second repair: the surface defects of the blank are polished with a portable grinding wheel, and the defects are checked by fluorescent penetration after pickling to see if they are cleaned up.

[0039] Step 5, heat treatment: heat the forging to 800±10℃ in a vacuum furnace, keep warm for 100±15min, and air cool after taking out of the furnace.

[0040] Step 6, physical and chemical testing: (1) Take one piece from the same batch of heat-treated forgings to test H content, macrostructure, and microstructure; (2) 100% hardness test of forgings; (3) Rough machining, thickness of each side is 2mm; (4) Ultrasonic flaw detection according to GB / T5193 standard A level.

[0041] Step 7, machining: Finish machining according to the size requirements of the mounting point parts drawing to obtain the finished product of the mounting point, such as Figure 3 shown.

[0042] Step 8, comprehensive inspection: (1) Finished product geometric dimensions, according to the dimensions of the mounting support part drawing; (2) H content ≤ 0.015%; (3) Hardness: HB (d) ≥ 3.35; (4) Macrostructure, according to GJB2744A standard 1 to 4; (5) Microstructure, according to GJB2744A standard 1 to 5; Ultrasonic flaw detection is accepted according to GB / T5193 standard A level.

[0043] The above is only an embodiment of the present invention, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by the present invention shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. An integral forming process for mounting support points of an aircraft engine, characterized in that: The following steps are involved: Step 1, forging design: combine the support point body and the support point flange edge into a whole, and design the forging size according to the processing allowance; Step 2, blank preparation: according to the forging design requirements, calculate the maximum cross-section of the forging and determine the blank specifications; Step 3, overall forming: After the blank is heated, it is placed in a bending device for bending, and immediately placed in a forming mold for pre-forming, and then sandblasted, repaired, and heated again, and placed in the forming mold again to complete the final forming; Step 4, heat treatment: heat the forging to 800±10℃ in a vacuum furnace, keep it warm for 100±15min, and air cool it after it comes out of the furnace; Step 5, physical and chemical testing: sampling and testing of H content, macrostructure, microstructure and hardness; Step 6, machining: machining the finished support point assembly according to the assembled parts drawing; Step 7, comprehensive inspection: physical and chemical testing of H content, macrostructure and microstructure again; geometric dimension testing; ultrasonic flaw detection.

2. The integral forming process of an aircraft engine mounting support point according to claim 1, characterized in that: The blank preparation in step 2 includes the following processes: material procurement, blanking, coating, heating, stripping, testing, rough machining and flaw detection.

3. The integral forming process of an aircraft engine mounting support point according to claim 2, characterized in that: The coating process refers to cleaning dirt and oil on the surface of the blank with salt water, heating it in an oven to 250-300°C after natural drying, then placing the blank in a paint bucket for dipping and coating, and then placing it on a turntable to dry, and placing the dried blank in an oven to heat it to 250-300°C.

4. The integral forming process of the mounting support point of an aircraft engine according to claim 3, characterized in that: The heating process is to place the coated blank into a box-type resistance furnace and heat it to 940±10°C and keep it warm for 60±10 minutes.

5. The integral forming process of an aircraft engine mounting support point according to claim 1, characterized in that: In the step three, the overall forming specifically includes the following processes: one glass coating, one heating, one bending, preforming, one sand blasting, one repair, two glass coatings, two heatings, final forming, two sand blastings and two repairs.

6. The integral forming process of the mounting support point of an aircraft engine according to claim 5, characterized in that: The preforming process is to clamp the bent blank into a forming die on a 2500T electric screw press within 5 seconds for forming.

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