Forging forming method for aero-engine fuel pump shell

Abstract

The invention relates to the technical field of aero-engine part manufacturing, in particular to a forging forming method for an aero-engine fuel pump shell. Comprising the following steps of S1, rough machining, S2, primary forging, S3, secondary forging, S4, secondary treatment, S5, tertiary forging and S6, tertiary treatment. According to the method, cracks and folding defects in the forging treatment process can be effectively removed through three times of forging and post-forging treatment, and the defects of corrosion spots, black spots, abnormal flower spots, peeling, bubbles, bruise and press-in objects can be effectively optimized.

Description

Technical Field

[0001] The invention relates to the technical field of aviation engine parts manufacturing, and in particular to a forging method for an aviation engine fuel pump housing. Background Art

[0002] The aircraft engine fuel pump is an indispensable component of the engine. Its main function is to supply fuel to the engine system so that it can operate smoothly. The pressure and flow control of the fuel pump is very important and can directly affect the working quality and efficiency of the engine. The fuel pump housing, as the outer protection of the fuel pump, can ensure that the internal components such as the motor, pressure limiter and check valve are not disturbed by the outside world during operation and maintain a stable operating environment. If there are defects in the housing, such as insufficient material density or problems in the manufacturing process, it may cause the fuel pump to work poorly and even cause safety hazards. At the same time, if the housing is deformed or interferes with internal components due to material or manufacturing problems, it may cause the fuel pump to fail. In extreme cases, it may cause the engine to shut down while the aircraft is flying, posing a threat to flight safety.

[0003] The most important alloy material in the forging process of the fuel pump housing is aluminum alloy. However, aluminum alloy structural parts are prone to defects during the forging process, which causes deformation of the fuel pump housing. Common defects of aluminum alloy are: 1. The root of the inner fillet of the upper mold is prone to "folding", and local corners are prone to folding; 2. The lower mold has obvious "folding", 100% in one place and partially in another place).

[0004] Aiming at defects such as folding of structural parts during forging, the present invention designs a forging method for a fuel pump housing of an aircraft engine. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a forging method for an aircraft engine fuel pump housing.

[0006] A forging method for an aircraft engine fuel pump housing comprises the following steps:

[0007] S1. Rough machining

[0008] First, a blank with a specification of Φ340±0.6×90±1mm is turned to a size of Φ330±0.4×88±1mm, and the surface roughness of both end surfaces of the blank is ≤Ra3.2, thereby obtaining a rough-machined blank;

[0009] S2, one-time forging

[0010] Heat the rough-processed billet to 470±10℃ and keep it warm for 50-150min, then roll it, flatten it radially to a thickness of 8+2.0-1.0mm and a width of 66-70mm, return the hot material to the furnace, and keep it warm for 25-75min at a final forging temperature of ≥380℃, air-cool it after forging to obtain a primary forging, and then clean it;

[0011] S3, secondary forging

[0012] Continue to heat the cleaned primary forging to 470±10℃ and keep it warm for 16~80min, then put the blank into the mold cavity horizontally for die forging, first strike with a hammer, the striking energy is 15±5% of the total striking energy of the equipment, then take out the blank, clean the dirt in the mold cavity, and then put the blank into the mold cavity for die forging, the striking energy is 30±5% of the total striking energy of the equipment, underpressure: 0.5~1.0, return the hot material to the furnace, and keep it warm for 8~40min at the final forging temperature ≥380℃, air cool after forging, and obtain the secondary forging;

[0013] S4, secondary processing

[0014] Place the forging in the trimming female die and trim it until the residual burr of the secondary forging is ≤1.0mm, the wall thickness difference is ≤0.8, and the offset is ≤0.4mm; clean it and grind it to remove defects, and grind the residual burr of the trimming, the residual burr is ≤1.0mm, and clean it again;

[0015] S5, three forging

[0016] Continue to heat the cleaned primary forging to 470±10℃ and keep it warm for 10-80min, put the forging into the die cavity according to the shape for die forging, the striking energy is 10±5% of the total striking energy of the equipment, return the hot material to the furnace, and keep it warm for 5-40min at the final forging temperature ≥380℃, air cool after forging, and obtain the tertiary forging;

[0017] S6, three-step processing

[0018] Place the forging in the trimming die and trim it until the residual burr of the secondary forging is ≤1.0mm, the wall thickness difference is ≤0.8, and the misalignment is ≤0.4mm; clean it and grind it until there are no defects, and grind the residual burrs of the trimming, and the residual burr is ≤1.0mm. Clean it again, and then grind it for the second time after solution treatment, correction and aging treatment, and send it for inspection.

[0019] Furthermore, before step S1, both ends of the blank are rounded to R3;

[0020] Note: After the billet is sawn, there will be serrated steps and a circle of sharp edges on its end face. The rounded corners at both ends of the billet can effectively avoid defects caused by forging serrated steps / sharp edges into the product surface during subsequent forging production.

[0021] Furthermore, in step S2, step S4 and step S5, the blank transfer time is ≤10s;

[0022] Note: After the billet comes out of the furnace, it will be exposed to the outside air and its temperature will continue to decrease. Therefore, the billet transfer time is required to be ≤10S, which can more effectively ensure the final forging temperature of the product and thus ensure the qualified performance of the forging.

[0023] Furthermore, the cleaning treatment is: removing grease and dirt from the surface of the forging, with the removal amount not exceeding 0.02 mm;

[0024] Note: The corrosion process is mainly to clean the grease and dirt on the surface of forgings. By controlling the amount of surface removal, it is possible to effectively prevent the forging surface from excessive corrosion and defects.

[0025] Further, in step S2, the blank is placed close to the damping table;

[0026] Note: A "damping platform" is added at the sharp corner of the pre-forging die to ensure rapid filling of metal at position C. Due to the large material demand at the sharp corner of the forging, the material filling at that position is slow during the pre-forging process. In fact, the material on both sides of the sharp corner fills faster and then converges to the sharp corner, thus forming a fold at the sharp corner. By adding a "damping platform", the material filling at the sharp corner can be effectively accelerated to prevent the occurrence of folding defects.

[0027] Furthermore, in step S6, the temperature of the solution treatment is 1080-1120°C, the heating rate is 3-5°C / min, and the temperature is kept for 1-3h;

[0028] Description: Solution treatment can effectively improve the plasticity and toughness of the fuel pump housing forgings, fully dissolve various phases of the alloy, strengthen the solid solution, improve the toughness and corrosion resistance, eliminate stress and soften, so as to continue processing or forming.

[0029] Furthermore, the correction method in step S3 is: placing a flat steel plate on a flat position of the die base, adjusting the upper and lower gaps: H = 8.5 ± 0.2 mm; before correction, cleaning the impurities and oil stains on the surface of the upper and lower flat plates, and then placing the forging on the die base for correction, and the striking energy is 3-5% of the total striking energy of the equipment;

[0030] Note: Since the product structure is a thin plate type, it will be slightly warped and deformed after production, which will affect subsequent processing. Therefore, the forging deformation is eliminated through correction to ensure subsequent product processing.

[0031] Furthermore, in step S3, the aging treatment method is: intermittent vibration aging and pulse current coordinated treatment are divided into three stages,

[0032] The first stage: the cold pressed forgings are heat-treated at 100-110°C for 5-7h, and then pulse current is applied at a frequency of 20000-25000Hz, a voltage of 30-50V, and a current density of 60-100A / mm for 30-50min, wherein the spectrum harmonic vibration aging treatment is performed during 30-70% of the current density application time;

[0033] The second stage: the frequency of the pulse current is adjusted to 15000-20000Hz, the voltage, current density and application time remain unchanged, and the spectrum harmonic vibration aging treatment is continued for 40-60% of the current density application time;

[0034] The third stage: the pulse voltage is adjusted to 10-30V, the current density is 5-40A / mm, the application frequency and application time remain unchanged, and the spectrum harmonic vibration aging treatment is continued for 20-80% of the current density application time.

[0035] Description: Vibration aging treatment can change the dislocation configuration of the crystal inside the forging, forming dislocation accumulation and entanglement, and increasing the dislocation density, which helps to delay the initiation and expansion of fatigue cracks. Compared with traditional thermal aging treatment, vibration aging treatment has the advantages of low energy consumption and low environmental pollution. Vibration aging treatment and pulse current synergistic treatment can significantly improve the strength and ductility of the material. Specifically, pulse current treatment can promote the movement of solute atoms in the solid solution process and increase the supersaturation of the sample, thereby promoting the coarsening and distribution of the strengthening phase in the aging treatment and improving the microstructure of the material. At the same time, electric pulse treatment can accelerate the microstructure evolution of the deformation aging alloy and improve the strength and ductility of the alloy.

[0036] Furthermore, the parameters of the spectrum harmonic vibration aging treatment are: frequency of 200-1000 Hz, vibration time of 5-15 min, vibration number of 3-10 times, and after each spectrum harmonic vibration aging treatment, the temperature is 2-4 mL / cm 2 The treatment liquid is sprayed on the surface of the forging with a spraying amount of , and then the same extrusion pressure is applied to the forging in the transverse / longitudinal / axial directions in sequence. The extrusion pressure of the first stage is 100-150MPa, the extrusion pressure of the second stage is 120-150% of the first stage, and the extrusion pressure of the third stage is 30-50% of the second stage;

[0037] The treatment liquid comprises, by weight percentage, 25-35% agar, 3-7% water-based graphite lubricant, 6-10% chitin, and the remainder is an aqueous solution containing 8-12%wt of alkyl phosphoric acid;

[0038] Description: Intermittent vibration and aging treatment can pre-evenly eliminate internal stress and reduce the possibility of defects; the combination of these two treatment methods can provide multiple advantages, especially when defects such as folding occur during the forging process; hydrocarbon phosphoric acid has lubricating properties and surface activity, which can reduce the tension on the alloy surface, thereby reducing the formation of cracks after welding; and when water-based graphite lubricant is sprayed in a high temperature environment, the rapid evaporation of water can take away part of the heat and play a certain cooling role, which helps to maintain the temperature balance during the aging treatment and prevent abnormal metal flow and folding defects caused by excessive temperature; at the same time, in low-temperature phosphoric acid aqueous solution, chitin can form a high-strength film, and the addition of chitin can also strengthen the overall structure of the material by forming hydrogen bonds and physical cross-linking networks, thereby reducing stress concentration and improving the toughness of the material; the addition of agar can strengthen the overall structure of the material by forming a physical cross-linking network, thereby reducing stress concentration.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] (1) The present invention can effectively remove cracks and folding defects in the forging process through three forgings and post-forging treatment. For the folding of the upper mold: by designing pre-forging, the local original angle of the forging is increased to improve the flow of raw materials; for the folding of the lower mold: by designing pre-forging, the outer contour cavity surface is appropriately reduced so that it can be smoothly placed in the final forging cavity during the final forging process to prevent the cavity wall from scratching and forming folds. In addition, the defects of corrosion points, black spots, abnormal mottled shapes, peeling, bubbles, bruises, and pressed objects can also be effectively optimized.

[0041] (2) The present invention adopts vibration aging treatment to change the dislocation configuration of the crystal inside the forging, forming dislocation accumulation and entanglement, and at the same time increasing the dislocation density, thereby delaying the initiation and expansion of fatigue cracks in the forging. In addition, the present invention uses vibration aging treatment and pulse current synergistic treatment, and utilizes pulse current treatment to promote the movement of solute atoms in the solid solution process, increase the supersaturation of the sample, promote the coarsening and distribution of the strengthening phase in the aging treatment, improve the microstructure of the material, and significantly improve the strength and ductility of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a schematic diagram of defects that occur during the forging of an aircraft engine fuel pump housing;

[0043] Figure 2 It is the cross-sectional diagram of the pre-forging and final forging of the blank group of the present invention;

[0044] Figure 3 It is a cross-sectional view of the pre-forging and final forging of Example 1 of the present invention;

[0045] Figure 4This is a schematic diagram of blank placement in Example 1 of the present invention;

[0046] Figure 5 1 is a diagram of pre-forging-contact analysis and pre-forging-folding analysis of Example 1 of the present invention;

[0047] Figure 6 1 is a final forging-contact analysis and a final forging-folding analysis diagram of Example 1 of the present invention;

[0048] Figure 7 is a plan view of the upper mold of the final forging of the present invention;

[0049] Figure 8 It is a plan view of the upper mold of the preforging of the present invention;

[0050] Fig. 9 It is a three-view drawing of the upper mold of the preforging of the present invention;

[0051] Fig.10 It is a three-view drawing of the upper mold of the preforging of the present invention;

[0052] Fig.11 It is a plan view of the pre-forging lower die of the present invention;

[0053] Fig.12 is a comparison chart of folding defect rates of Examples 1 to 3 of the present invention and Control Groups 1 to 2;

[0054] Fig.13 It is a comparison chart of the tensile strength of Examples 1 to 3 of the present invention and Control Groups 1 to 2;

[0055] Fig.14 It is a comparison chart of the elongation of Examples 1 to 3 of the present invention and Control Groups 1 to 2;

[0056] Fig.15 It is a comparison chart of folding defect rates of Example 1, Examples 4 to 11 and Control Groups 3 to 4 of the present invention;

[0057] Fig.16 It is a comparison chart of the tensile strength of Example 1, Examples 4 to 11 and Control Groups 3 to 4 of the present invention;

[0058] Fig.17 It is a comparison chart of the elongation of Example 1, Examples 4 to 11 and Control Groups 3 to 4 of the present invention;

[0059] Fig.18 It is a comparison chart of folding defect rates of Example 1, Examples 12 to 18 and Control Groups 5 to 6 of the present invention;

[0060] Fig.19It is a comparison chart of the tensile strength of Example 1, Examples 12 to 18 and Control Groups 5 to 6 of the present invention;

[0061] Fig. 20 It is a comparison chart of the elongation of Example 1, Examples 12 to 18 and Control Groups 5 to 6 of the present invention;

[0062] In the figure: Position ①: The pre-forging is offset by 0.2mm relative to the final forging;

[0063] Position ②: Pre-forging is offset by 1.0mm relative to final forging;

[0064] Position ③: Final forging R = 1.2, pre-forging design R = 2.0;

[0065] Position ④: Final forging R=2.5, pre-forging design R=3.5;

[0066] Position ⑤: Final forging R = 1.2, pre-forging design R = 1.8;

[0067] Position ⑥: Final forging draft = 7°, pre-forging draft = 9°. DETAILED DESCRIPTION

[0068] In order to further illustrate the method adopted by the present invention and the effect achieved, the technical solution of the present invention will be clearly and completely described in combination with experiments below.

[0069] Embodiment 1: A forging method for an aircraft engine fuel pump housing, comprising the following steps:

[0070] S1. Rough machining

[0071] First, a blank with a specification of Φ340×90 mm is turned into a size of Φ330×88 mm, and the surface finish of both end surfaces of the blank is not less than Ra3.2, and then both end surfaces of the blank are rounded to R3 to obtain a rough-machined blank;

[0072] S2, one-time forging

[0073] The rough-processed billet is heated to 470°C and kept at this temperature for 100 minutes, then rolled, and the billet is flattened radially to a thickness of 9.0 mm and a width of 68 mm. The hot material is returned to the furnace and kept at a final forging temperature of 380°C for 55 minutes. After forging, it is air-cooled to obtain a primary forging, and then cleaned;

[0074] S3, secondary forging

[0075] Continue to heat the cleaned primary forging to 470°C and keep it warm for 40 minutes, then put the blank into the mold cavity horizontally for die forging, first strike a hammer, the striking energy is 15% of the total striking energy of the equipment, then take out the blank, clean the dirt in the mold cavity, and then put the blank into the mold cavity for die forging, the striking energy is 30% of the total striking energy of the equipment, underpressure: 0.8, hot material is returned to the furnace, and kept warm for 25 minutes at the final forging temperature of 380°C, air-cooled after forging, and the secondary forging is obtained; it should be noted that in this scheme, the striking equipment refers to the commercially available 315T electric screw press;

[0076] S4, secondary processing

[0077] Place the forging in the trimming female die and trim it until the residual burr of the secondary forging is 1.0mm, the wall thickness difference is 0.8, and the offset is 0.4mm; clean it and grind it to remove defects, and grind the residual burr of the trimming to 1.0mm, and clean it again;

[0078] S5, three forging

[0079] Continue to heat the cleaned primary forging to 470℃ and keep it warm for 50min, put the forging into the die cavity according to the shape for die forging, the striking energy is 10% of the total striking energy of the equipment, return the hot material to the furnace, and keep it warm for 25min at the final forging temperature of 380℃, air cool after forging, and obtain the tertiary forging;

[0080] S6, three-step processing

[0081] Place the forging in the trimming die and trim it until the residual burr of the secondary forging is 1.0mm, the wall thickness difference is 0.8, and the offset is 0.4mm; clean and grind it until there are no defects, and grind the residual burr of the trimming to 1.0mm, clean it again, and then grind it again after solution treatment, correction, aging treatment, and inspection;

[0082] During the grinding process, all cracks, folds and corrosion marks on the machined surface of the forging must be removed. Peeling, bubbles, bruises, pressed objects and other defects are allowed to be inspected and cleaned, and their depths are determined, but it is necessary to ensure that the forging has a nominal machining allowance of no less than one-half; cracks, folds and other defects that affect the use of the forging on the non-machined surface should be removed, and the parts where the defects are removed should ensure the minimum limit size of the single side of the forging;

[0083] Before step S1, both ends of the blank are rounded to R3;

[0084] In step S2, step S4 and step S5, the blank transfer time is 10s;

[0085] The cleaning process is to remove grease and dirt from the surface of the forging, with a removal amount of 0.02mm;

[0086] In step S2, the blank is placed close to the damping table; the distance position is as follows Figure 4 As shown;

[0087] In step S3, the temperature of the solution treatment is 1100°C, the heating rate is 4°C / min, and the temperature is kept for 2h;

[0088] The correction method described in step S3 is: lay a flat steel plate on the flat position of the die base, adjust the upper and lower gaps: H = 8.5mm; before correction, clean the impurities and oil stains on the surface of the upper and lower flat plates, and then place the forging on the die base for correction. The impact energy is 4% of the total impact energy of the equipment.

[0089] Example 2: Different from Example 1, in step S2, the rough-processed billet is heated to 460°C and kept warm for 50 minutes, and then rolled, and the billet is radially flattened to a thickness of 7.0 mm and a width of 66 mm. The hot material is returned to the furnace and kept warm for 25 minutes at a final forging temperature of 400°C. After forging, it is air-cooled to obtain a primary forging, which is then cleaned.

[0090] Example 3: Different from Example 1, in step S2, the rough-processed billet is heated to 480°C and kept warm for 150 minutes, and then rolled, and the billet is radially flattened to a thickness of 9.0 mm and a width of 70 mm. The hot material is returned to the furnace and kept warm for 75 minutes at a final forging temperature of 385°C. After forging, it is air-cooled to obtain a primary forging, which is then cleaned.

[0091] Example 4: Different from Example 1, in step S3, the cleaned primary forging is continued to be heated to 460°C and kept warm for 16 minutes, then the blank is placed horizontally into the mold cavity for die forging, and a hammer is struck first with an impact energy of 10% of the total impact energy of the equipment. Then the blank is taken out, the dirt in the mold cavity is cleaned, and then the blank is placed into the mold cavity for die forging with an impact energy of 25% of the total impact energy of the equipment. The underpressure is 0.5, the hot material is returned to the furnace, and kept warm for 8 minutes at a final forging temperature of 380°C, and air-cooled after forging to obtain a secondary forging.

[0092] Example 5: Different from Example 1, in step S3, the cleaned primary forging is continued to be heated to 480°C and kept warm for 80 minutes, then the blank is placed horizontally into the mold cavity for die forging, and a hammer is struck first with an impact energy of 20% of the total impact energy of the equipment. Then the blank is taken out, the dirt in the mold cavity is cleaned, and then the blank is placed into the mold cavity for die forging with an impact energy of 35% of the total impact energy of the equipment. The underpressure is 1.0, the hot material is returned to the furnace, and kept warm for 40 minutes at a final forging temperature of 380°C, and air-cooled after forging to obtain a secondary forging.

[0093] Example 6: Different from Example 1, in step S3, the temperature of the solution treatment is 1080°C, the heating rate is 3°C / min, and the insulation time is 1h.

[0094] Example 7: Different from Example 1, in step S3, the temperature of the solution treatment is 1120°C, the heating rate is 5°C / min, and the insulation time is 3h.

[0095] Example 8: Different from Example 1, the correction method described in step S3 is: lay a flat steel plate on the flat position of the die base, adjust the upper and lower gaps: H = 8.3mm; before correction, clean the impurities and oil stains on the surface of the upper and lower flat plates, and then place the forging on the die base for correction. The impact energy is 3% of the total impact energy of the equipment.

[0096] Example 9: Different from Example 1, the correction method described in step S3 is: lay a flat steel plate on the flat position of the die base, adjust the upper and lower gaps: H = 8.7mm; before correction, clean the impurities and oil stains on the surface of the upper and lower flat plates, and then place the forging on the die base for correction. The impact energy is 5% of the total impact energy of the equipment.

[0097] Example 10: Different from Example 1, in step S5, the cleaned primary forging is continued to be heated to 460°C and kept warm for 10 minutes, the forging is placed into the mold cavity according to the shape for die forging, the striking energy is 5% of the total striking energy of the equipment, the hot material is returned to the furnace, and kept warm for 5 minutes at the final forging temperature of 380°C, and air-cooled after forging to obtain a tertiary forging.

[0098] Example 11: Different from Example 1, in step S5, the cleaned primary forging is continued to be heated to 480°C and kept warm for 80 minutes, the forging is placed into the mold cavity according to the shape for die forging, the striking energy is 15% of the total striking energy of the equipment, the hot material is returned to the furnace, and kept warm for 40 minutes at a final forging temperature of 380°C, and air-cooled after forging to obtain a tertiary forging.

[0099] Embodiment 12: Different from Embodiment 1, in step S3, the aging treatment method is: intermittent vibration aging and pulse current coordinated treatment are divided into three stages,

[0100] The first stage: the cold pressed forgings are heat-treated at 105°C for 6 hours, and then pulse current is applied at a frequency of 22500Hz, a voltage of 40V, and a current density of 80A / mm. The application time is 30 to 50 minutes, and the spectrum harmonic vibration aging treatment is carried out during 30 to 70% of the current density application time;

[0101] The second stage: the frequency of the pulse current is adjusted to 18000Hz, the voltage, current density and application time remain unchanged, and the spectrum harmonic vibration aging treatment is continued for 40-60% of the current density application time;

[0102] The third stage: the pulse voltage is adjusted to 20V, the current density is 25A / mm, the application frequency and application time remain unchanged, and the spectrum harmonic vibration aging treatment is continued for 20-80% of the current density application time;

[0103] The parameters of spectrum harmonic vibration aging treatment are: frequency 600Hz, vibration time 10min, vibration number 6 times, and after each spectrum harmonic vibration aging treatment, the pressure is 3mL / cm 2 The treatment liquid is sprayed on the surface of the forging with a spraying amount of , and then the same extrusion pressure is applied to the forging in the transverse / longitudinal / axial directions in sequence. The extrusion pressure in the first stage is 125MPa, the extrusion pressure in the second stage is 130% of the first stage, and the extrusion pressure in the third stage is 40% of the second stage;

[0104] The treatment liquid comprises, by weight percentage, 30% agar, 5% water-based graphite lubricant, 8% chitin, and the balance is a 10%wt aqueous solution of hydrocarbon phosphoric acid.

[0105] Embodiment 13: Different from Embodiment 12, in step S3, the aging treatment method is: intermittent vibration aging and pulse current coordinated treatment are carried out in three stages.

[0106] The first stage: the cold pressed forgings are heat-treated at 100°C for 5 hours, and then pulse current is applied at a frequency of 20,000 Hz, a voltage of 30 V, and a current density of 60 A / mm for 30 to 50 minutes, wherein the spectrum harmonic vibration aging treatment is performed during 30 to 70% of the current density application time;

[0107] The second stage: the frequency of the pulse current is adjusted to 15000Hz, the voltage, current density and application time remain unchanged, and the spectrum harmonic vibration aging treatment is continued for 40-60% of the current density application time;

[0108] The third stage: the pulse voltage is adjusted to 10V, the current density is 5A / mm, the application frequency and application time remain unchanged, and the spectrum harmonic vibration aging treatment is continued for 20 to 80% of the current density application time.

[0109] Embodiment 14: Different from Embodiment 12, in step S3, the aging treatment method is: intermittent vibration aging and pulse current coordinated treatment are carried out in three stages.

[0110] The first stage: the cold pressed forgings are heat-treated at 110°C for 7 hours, and then pulse current is applied at a frequency of 25000Hz, a voltage of 50V, and a current density of 100A / mm for 50 minutes, wherein the spectrum harmonic vibration aging treatment is performed during 30% to 70% of the current density application time;

[0111] The second stage: the frequency of the pulse current is adjusted to 20000Hz, the voltage, current density and application time remain unchanged, and the spectrum harmonic vibration aging treatment is continued for 40-60% of the current density application time;

[0112] The third stage: the pulse voltage is adjusted to 30V, the current density is 40A / mm, the application frequency and application time remain unchanged, and the spectrum harmonic vibration aging treatment is continued for 20 to 80% of the current density application time.

[0113] Example 15: Different from Example 12, the parameters of the spectrum harmonic vibration aging treatment are: frequency is 200 Hz, vibration time is 5 min, vibration number is 3 times, and after each spectrum harmonic vibration aging treatment, the temperature is 2 mL / cm 2 The treatment liquid is sprayed on the surface of the forging with a spraying amount of , and then the same extrusion pressure is applied to the forging in the transverse / longitudinal / axial directions in sequence. The extrusion pressure in the first stage is 100MPa, the extrusion pressure in the second stage is 120% of the first stage, and the extrusion pressure in the third stage is 30% of the second stage.

[0114] Example 16: Different from Example 12, the parameters of the spectrum harmonic vibration aging treatment are: frequency is 1000 Hz, vibration time is 15 min, vibration number is 10 times, and each spectrum harmonic vibration aging treatment is carried out at 4 mL / cm 2 The treatment liquid is sprayed on the surface of the forging with a spraying amount of , and then the same extrusion pressure is applied to the forging in the transverse / longitudinal / axial directions in sequence. The extrusion pressure in the first stage is 150MPa, the extrusion pressure in the second stage is 150% of the first stage, and the extrusion pressure in the third stage is 50% of the second stage.

[0115] Example 17: Different from Example 12, the treatment liquid includes, by mass percentage, 25% agar, 3% water-based graphite lubricant, 6% chitosan, and the balance is an 8% aqueous solution of hydrocarbon phosphoric acid.

[0116] Example 18: Different from Example 12, the treatment liquid includes, by mass percentage, 35% agar, 7% water-based graphite lubricant, 10% chitosan, and the remainder is a 12% aqueous solution of hydrocarbon phosphoric acid.

[0117] Experimental Example: The description of this experimental example is based on the schemes described in Examples 1 to 18, and is intended to illustrate the practical application effect of the present invention. The appearance and mechanical properties of the aircraft engine fuel pump housing obtained in Examples 1 to 18 were tested respectively, and a comparative example was set.

[0118] The fuel pump housing forgings produced by the methods of Examples 1 to 18 were subjected to 100% visual inspection. The fuel pump housing forgings of Examples 1 to 18 all had good surface quality and no defects such as cracks and folds. Moreover, the fuel pump housings of Examples 12 to 18 had better mechanical properties and higher quality than those of Examples 1 to 11. Comparative Examples 1 to 5 had slight cracks and folds on the surface, and the surface quality was inferior to that of Examples 1 to 18, indicating that the methods of Examples 1 to 18 were improved compared to those in the comparative examples. The metallographic structure of the aviation fuel pump housings obtained in Examples 1 to 18 was observed, and it was found that the grain size was 8 or less, and was evenly distributed.

[0119] 1. Explore the effects of blank end face turning / chamfering and flattening / pre-forging shape design on the performance of engine fuel pump housing

[0120] Control group 1: Different from Example 1, the two end surfaces of the blank are not chamfered.

[0121] Control group 2: Different from Example 1, no treatment is performed after flattening during the one-step forging process.

[0122] Conclusion: From Figure 12 to Figure 14 From the comparison between Examples 1 to 3 and Control Groups 1 to 2, it can be seen that in Examples 1 to 3, the end face turning / chamfering of the billet can effectively avoid the defects formed on the surface of the forged product due to the serrated steps / sharp edges; the shape of the final forging can be effectively matched by flattening the billet / pre-forging shape design, thereby avoiding the occurrence of surface defects of the product; the performance of the fuel pump housing obtained in Control Groups 1 to 2 is lower than that in Examples 1 to 3, and the defect rate is also significantly improved.

[0123] 2. Explore the impact of various parameter changes during forging on the performance of the engine fuel pump housing

[0124] Control group 3: Different from Example 1, the swinging position of the blank is not limited.

[0125] Control group 4: Different from Example 1, no additional treatment of impurities and oil stains on the surface of the plate was performed before calibration.

[0126] Conclusion: Pass Figures 15 to 17As shown, it can be found that the control group 3 does not limit the swing position of the blank, which will also cause a significant decrease in the performance of the fuel pump housing. In Example 1, a "damping platform" is added at the sharp corner position of the pre-forging die to ensure rapid filling of metal at position C. In addition, due to the large material demand at the sharp corner position of the forging, the material filling at that position is slow during the pre-forging process. In fact, the material on both sides of the sharp corner is filled faster and then converges to the sharp corner position, thereby forming a fold at the sharp corner position. By adding a "damping platform", the material filling at the sharp corner position can be effectively accelerated to prevent the occurrence of folding defects. In the control group 4, the lack of treatment of the upper and lower flat plate positions weakens the folding defect elimination rate of the obtained fuel pump housing. In the entire production process of Examples 1 and Examples 4 to 11, the heating temperature, insulation time, surface cleaning, heat treatment and other parameters that are too large or too small will cause the product quality and the qualified rate of the product physical and chemical items to decrease. Among them, the engine fuel pump housing obtained under the parameters of Example 1 has the lowest defect rate and the best mechanical properties.

[0127] 3. Explore the effect of aging treatment methods on the performance of engine fuel pump housing

[0128] Control group 5: Different from Example 12, the time of spectrum harmonic vibration aging treatment is not adjusted with each stage.

[0129] Control group 6: Different from Example 12, no extrusion force was applied to the forging.

[0130] Control group 7: Different from Example 12, no water base stone was added to the treatment liquid.

[0131] Conclusion: Pass Figure 18 to Figure 20It can be concluded that the performance of the engine fuel pump housing prepared in Examples 12 to 18 is significantly improved and the folding defects are smaller than those in Example 1, and the performance effect of Example 12 is better; and from the comparison of Examples 12 to 14 and Control Group 5, it can be concluded that the spectrum harmonic vibration aging treatment is performed in stages within 30% to 70% of the time, 40% to 60% of the time, and 20% to 80% of the time of the pulse current application. It can help to make the metal flow at the fold more uniform in the first stage, thereby reducing the depth and roughness of the surface fold, making the surface smoother and reducing the defect rate. In the second stage, with the optimization of the crystal structure and the further adjustment of the internal stress, the deformation coordination of the internal microstructure of the forging is better during the stretching process, and the bonds between atoms can be broken and reformed more uniformly during the stretching process. The elongation of the forging is improved, and it can have better deformation ability before fracture; the longer treatment time in the third stage makes the dislocation movement and crystal structure adjustment inside the forging more sufficient, and the combined effect of pulse current and vibration aging continuously affects the forging in this wide time range, so that the internal crystal structure is continuously optimized, forming a denser and more stable structure, thereby improving the tensile strength of the forging; while in the control group 6, the absence of extrusion pressure on the forging will cause the effect of the treatment liquid, thereby weakening its mechanical properties; the lack of water-based graphite lubrication in the control group 7 will make the temperature unstable during the aging treatment process, thereby causing abnormal metal flow and folding defects caused by excessively high temperatures; in summary, the scheme of Example 12 can further improve the performance and folding defects of the engine fuel pump housing, thereby improving the forging efficiency.

Claims

1. A forging method for an aircraft engine fuel pump housing, characterized in that: The following steps are involved: S1. Rough machining First, a blank with a specification of Φ340±0.6×90±1mm is turned to a size of Φ330±0.4×88±1mm, and the surface roughness of both end surfaces of the blank is ≤Ra3.2, thereby obtaining a rough-machined blank; S2, one-time forging Heat the rough-processed billet to 470±10℃ and keep it warm for 50-150min, then roll it, flatten it radially to a thickness of 8+2.0-1.0mm and a width of 66-70mm, return the hot material to the furnace, and keep it warm for 25-75min at a final forging temperature of ≥380℃, air-cool it after forging to obtain a primary forging, and then clean it; S3, secondary forging Continue to heat the cleaned primary forging to 470±10℃ and keep it warm for 16~80min, then put the blank into the die cavity horizontally for die forging, first strike with a hammer, the striking energy is 15±5% of the total striking energy of the equipment, then take out the blank, clean the dirt in the die cavity, and then put the blank into the die cavity for die forging, the striking energy is 30±5% of the total striking energy of the equipment, underpressure: 0.5~1.0, the hot material is returned to the furnace and kept at the final forging temperature ≥380℃ for 8~40min, air-cooled after forging to obtain the secondary forging; S4, secondary processing Place the forging in the trimming female die and trim it until the residual burr of the secondary forging is ≤1.0mm, the wall thickness difference is ≤0.8, and the offset is ≤0.4mm; clean it and grind it to remove defects, and grind the residual burr of the trimming, the residual burr is ≤1.0mm, and clean it again; S5, three forging Continue to heat the cleaned primary forging to 470±10℃ and keep it warm for 10-80min, put the forging into the die cavity according to the shape for die forging, the striking energy is 10%±5% of the total striking energy of the equipment, return the hot material to the furnace, and keep it warm for 5-40min at the final forging temperature ≥380℃, air cool after forging, and obtain the tertiary forging; S6, three-step processing Place the forging in the trimming die and trim it until the residual burr of the secondary forging is ≤1.0mm, the wall thickness difference is ≤0.8, and the misalignment is ≤0.4mm; clean it and grind it until there are no defects, and grind the residual burrs of the trimming, and the residual burr is ≤1.0mm. Clean it again, and then grind it for the second time after solution treatment, correction and aging treatment, and send it for inspection.

2. A forging method for an aircraft engine fuel pump housing as claimed in claim 1, characterized in that: Before step S1, both ends of the blank are rounded to R3.

3. The forging method for an aircraft engine fuel pump housing according to claim 1, characterized in that: In step S2, step S4 and step S5, the blank transfer time is ≤10s.

4. The forging method for an aircraft engine fuel pump housing according to claim 1, characterized in that: The cleaning treatment is to remove grease and dirt on the surface of the forging, with the removal amount being ≤0.02mm.

5. The forging method for an aircraft engine fuel pump housing according to claim 1, characterized in that: In step S6, the temperature of the solution treatment is 1080-1120°C, the heating rate is 3-5°C / min, and the heat preservation time is 1-3h.

6. The forging method for an aircraft engine fuel pump housing according to claim 1, characterized in that: The correction method described in step S6 is: lay a flat steel plate on the flat position of the die base, adjust the upper and lower gaps: H = 8.5 ± 0.2 mm; before correction, clean the impurities and oil stains on the surface of the upper and lower flat plates, and then place the forging on the die base for correction. The impact energy is 3% ± 5% of the total impact energy of the equipment.

7. The forging method for an aircraft engine fuel pump housing according to claim 1, characterized in that: In step S6, the aging treatment method is: intermittent vibration aging and pulse current coordinated treatment are divided into three stages. The first stage: the cold pressed forgings are heat-treated at 100-110°C for 5-7h, and then pulse current is applied at a frequency of 20000-25000Hz, a voltage of 30-50V, and a current density of 60-100A / mm for 30-50min, wherein the spectrum harmonic vibration aging treatment is performed during 30-70% of the current density application time; The second stage: the frequency of the pulse current is adjusted to 15000-20000Hz, the voltage, current density and application time remain unchanged, and the spectrum harmonic vibration aging treatment is continued for 40-60% of the current density application time; The third stage: the pulse voltage is adjusted to 10-30V, the current density is 5-40A / mm, the application frequency and application time remain unchanged, and the spectrum harmonic vibration aging treatment is continued for 20-80% of the current density application time.

8. The forging method for an aircraft engine fuel pump housing according to claim 7, characterized in that: The parameters of the spectrum harmonic vibration aging treatment are: frequency of 200-1000 Hz, vibration time of 5-15 min, vibration times of 3-10 times, and after each spectrum harmonic vibration aging treatment, the temperature is adjusted to 2-4 mL / cm 2 The treatment liquid is sprayed on the surface of the forging with a spraying amount of , and then the same extrusion pressure is applied to the forging in the transverse / longitudinal / axial directions in sequence. The extrusion pressure of the first stage is 100-150MPa, the extrusion pressure of the second stage is 120-150% of the first stage, and the extrusion pressure of the third stage is 30-50% of the second stage; The treatment liquid comprises, by weight percentage, 25-35% agar, 3-7% water-based graphite lubricant, 6-10% chitin, and the remainder is an aqueous solution containing 8-12%wt of hydrocarbon phosphoric acid.

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