A forming process and forming tool for an aero-engine deep-cylinder thin-wall part

Abstract

The application discloses an aero-engine deep-cylinder thin-wall part forming process and forming tool, belongs to the high-temperature alloy ring part forging technical field, and comprises the following steps: 1. the blank is placed in a heating furnace and heated to the initial forging temperature of the material. 2. the blank is upset, square elongated, rounded, upset, punched and expanded on a forging hammer. 3. the blank is roughly turned. 4. the blank is heated in a furnace. 5. the re-heated blank is expanded on a forging hammer to obtain a GH4169 load-cylinder forging. 6. the forging is subjected to solid solution heat treatment. 7. the solid-solution-treated forging is sampled and subjected to physical and chemical tests. 8. the forging that passes the physical and chemical tests is roughly turned. 9. the roughly-turned forging is subjected to ultrasonic inspection. The application can increase the upper limit of the forming weight of the GH4169 deep-cylinder thin-wall part by optimizing the forming process, meanwhile, the upsetting, square elongation, rounding and upsetting steps make the deformation of the forging uniform, and effectively ensure the uniformity of the grain structure of the forging.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high-temperature alloy ring forging technology, in particular, to an aero-engine deep cylinder thin-wall part forming process. In addition, the present application also relates to a forming tool applied to the aero-engine deep cylinder thin-wall part forming process. BACKGROUND

[0002] The information provided in this section is for the purpose of generally presenting the context of the application. To the extent that the descriptions in this section describe the work of the inventors, and to the extent that the descriptions are not considered prior art by themselves or in combination with other prior art, they are not an admission that the field investigated is the field of the application or a field sought to be investigated by the claimed application.

[0003] GH4169 alloy is widely used in the field of aviation and aerospace due to its excellent high-temperature performance. The load-bearing cylinder of a certain aero-engine is made of GH4169 alloy and is a deep cylinder thin-wall part. The wall thickness is thin, the height is high, and the total weight of a single forging is large. Due to the large height of the forging, combined with the large deformation resistance of GH4169, the inner hole forming is difficult, the inner hole size is difficult to guarantee during punching, and folding defects are prone to occur. In addition, uneven deformation is prone to occur, resulting in mixed crystals. Please refer to the schematic diagram of the high-magnification structure mixed crystal of the load-bearing cylinder formed by the existing process in the accompanying drawings. Figure 1 The schematic diagram of the high-magnification structure mixed crystal of the load-bearing cylinder formed by the existing process.

[0004] In order to improve the upper limit of the forging equipment for the deep cylinder thin-wall part made of GH4196 alloy and ensure the uniformity of the grain structure of the forging, an optimized forming process is provided, and a modified forming tool is used to effectively improve the quality of the final product.

[0005] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present application, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0006] In view of at least one of the above technical problems, the present application provides an aero-engine deep cylinder thin-wall part forming process. For GH4169 deep cylinder thin-wall parts, the upper limit of the forming weight of the GH4169 deep cylinder thin-wall part can be improved by optimizing the forming process. At the same time, in view of the uneven deformation characteristics during the upsetting process, the upsetting, square elongation, rounding, and upsetting steps are used to make the forging deformation uniform, effectively ensuring the uniformity of the grain structure of the forging.

[0007] The present application also provides a forming tool applied to the aero-engine deep cylinder thin-wall part forming process.

[0008] According to one aspect of the present application, an aero-engine deep cylinder thin-wall part forming process is provided, comprising the following steps:

[0009] S100, according to the size requirement of the deep-cylinder thin-wall part to be processed, the diameter and length of the GH4169 rod blank are selected;

[0010] S200, the blank is placed in a heating furnace for preheating, the preheating temperature is 800±10℃, and the blank is kept for 168-212min;

[0011] S300, the blank after preheating and keeping is heated to (980-1030) ±20℃, and then kept for 101-228min;

[0012] S400, the blank after heating is sequentially upset, square elongated, rounded, upset and punched on a free forging hammer device;

[0013] S500, the blank is roughed to the preset forming size;

[0014] S600, the blank after roughing is heated by re-melting, preheating at 800±10℃ and keeping for 64-104min, then heating to 960-1050℃ and keeping for 39-95min;

[0015] S700, the blank after re-melting is expanded on a free forging hammer to obtain a GH4169 load-bearing cylinder forging;

[0016] S800, the forging after expansion is subjected to solid solution heat treatment;

[0017] S900, the forging after solid solution heat treatment is sampled for physical and chemical tests, and the forging that passes the physical and chemical tests is roughed to the specified size, and the forging after roughing is subjected to ultrasonic inspection.

[0018] In some embodiments of the present application, the striking energy or tonnage of the free forging device is selected according to the deformation work required for the forging in step S400, and the calculation formula of the upsetting deformation work A required for upsetting the blank is as follows:

[0019]

[0020] In the formula, σ S is the true flow stress at the corresponding deformation temperature and speed, unit: MPa; D1 and H1 are the diameter and height of the blank, unit: mm; D2 and H2 are the diameter and height of the blank after upsetting, unit: mm; V is the volume of the forging, unit: mm 3 .

[0021] In some embodiments of the present application, in step S400, the calculation formula of the striking energy E of the free forging device during upsetting is as follows:

[0022]

[0023] In the formula: E is the required striking energy of the free forging equipment, in J; η is the striking efficiency, usually η = 0.7-0.9.

[0024] In some embodiments of the present application, in step S400, the calculation formula of the tonnage G of the forging hammer of the free forging equipment during upsetting is as follows:

[0025]

[0026] In the formula: g is the acceleration of gravity, g = 9.8 / s 2 ; v is the striking speed of the forging hammer, usually v = 5-6 m / s.

[0027] In some embodiments of the present application, in step S400, the blank is transferred from the heating furnace to the free forging equipment for forging, and the transfer time should not exceed 15 s.

[0028] In some embodiments of the present application, in step S400, the temperature of the forged piece should be paid attention to during the forging process on the free forging hammer equipment, and the temperature of the forged piece is detected by an optical pyrometer or an infrared temperature detector, and the final forging temperature of the forged piece should not be lower than 900℃.

[0029] In some embodiments of the present application, in step S400, the blank should be continuously rotated around the blank axis during upsetting, and the blank is flipped up and down when the upsetting process is half way.

[0030] In some embodiments of the present application, in step S800, when the forged piece is ≤780℃, it is put into the heating furnace, the heating temperature is (770℃-790℃) ±10℃, the temperature is kept for 2-4 h, the temperature is raised to (960℃-980℃) ±10℃ with the furnace, the temperature is kept for 2-2.5 h, and then the forged piece is oil-cooled.

[0031] According to another aspect of the present application, an aviation engine deep cylinder thin-wall piece forming tool is also provided, which is applied to the aviation engine deep cylinder thin-wall piece forming process, and comprises a forward punch and a backward punch. The forward punch is connected to a punching device to punch the deep cylinder thin-wall piece blank through the forward punch, and the backward punch is connected to the punching device to punch out the bottom sheet of the deep cylinder thin-wall piece blank through the backward punch.

[0032] In some embodiments of the present application, the forward punch and the backward punch are both conical frustums with the top wider than the bottom, and the bottom surface and the top surface of the forward punch and the backward punch are both chamfered at the same angle. The minimum diameter of the backward punch is smaller than that of the forward punch, and the height of the backward punch is higher than that of the forward punch.

[0033] The present application has the following beneficial effects:

[0034] The aero-engine deep cylinder thin-wall part forming process of the application is aimed at GH4169 deep cylinder thin-wall parts. By optimizing the forming process steps and process parameters, the upper limit of the forming weight of the GH4169 deep cylinder thin-wall part can be increased by more than 30%. At the same time, aiming at the uneven deformation characteristics of the upsetting process, the upsetting, square elongation, rounding, upsetting steps are used to make the deformation of the forgings uniform, effectively ensuring the uniformity of the grain structure of the forgings. Among them, the square elongation and rounding are used to make the forgings bear force in all directions. In addition, the application also provides a selection and calculation method for the striking energy or tonnage of the free forging equipment, which can further improve the precision of forging and effectively improve the quality of the product. The application overcomes the problems of punching forming difficulty and easy to produce mixed crystals of the existing process, and has significant economic benefits.

[0035] The aero-engine deep cylinder thin-wall part forming tool of the application also has the above beneficial effects. At the same time, the forming tool of the application can also achieve the effect of more easily punching out the punching bottom sheet, and the tool structure is simple and efficient, and is very convenient to use, which is beneficial to further improve the processing efficiency.

[0036] Of course, implementing any product of the application does not necessarily need to achieve all the advantages described above. In addition to the purposes, features and advantages described above, the application has other purposes, features and advantages. The application will be further described below with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0037] The drawings that form a part of this application are intended to provide further understanding of the application, and the schematic embodiments of the application and their descriptions are used to explain the application, and do not constitute an improper limitation on the application. In the drawings:

[0038] Figure 1 is a schematic diagram of high-magnification mixed crystal of the bearing cylinder formed by the existing process;

[0039] Figure 2 is a process flow diagram of the preferred embodiment of the application;

[0040] Figure 3 is a structure schematic diagram of the positive punch of the preferred embodiment of the application;

[0041] Figure 4 is a structure schematic diagram of the reverse punch of the preferred embodiment of the application;

[0042] Figure 5 is a stress schematic diagram of the deep cylinder thin-wall part of the preferred embodiment of the application;

[0043] Figure 6 is a microstructure 100X structure diagram of the physicochemical test of the forging of the first embodiment of the application;

[0044] Figure 7 is a microstructure 500X tissue map of the forge physical and chemical test of the first embodiment of the application;

[0045] Figure 8 is a microstructure 100X tissue map of the forge physical and chemical test of the second embodiment of the application;

[0046] Figure 9 is a microstructure 500X tissue map of the forge physical and chemical test of the second embodiment of the application;

[0047] Figure 10 is a microstructure 100X tissue map of the forge physical and chemical test of the third embodiment of the application;

[0048] Figure 11 is a microstructure 500X tissue map of the forge physical and chemical test of the third embodiment of the application;

[0049] Legend: 1, forward punch; 2, reverse punch. DETAILED DESCRIPTION

[0050] The embodiments of the application are described in detail below with reference to the accompanying drawings, but the application can be implemented in various different manners limited and covered by the following description.

[0051] Figure 1 is a schematic diagram of high-magnification tissue mixed crystals of a force-bearing cylinder formed by an existing process; Figure 2 is a process flow schematic diagram of the preferred embodiment of the application; Figure 3 is a structural schematic diagram of a forward punch of the preferred embodiment of the application;

[0052] Figure 4 is a structural schematic diagram of a reverse punch of the preferred embodiment of the application; Figure 5 is a stress schematic diagram of a deep-cylinder thin-walled part of the preferred embodiment of the application; Figure 6 is a microstructure 100X tissue map of the forge physical and chemical test of the first embodiment of the application; Figure 7 is a microstructure 500X tissue map of the forge physical and chemical test of the first embodiment of the application; Figure 8 is a microstructure 100X tissue map of the forge physical and chemical test of the second embodiment of the application; Figure 9 is a microstructure 500X tissue map of the forge physical and chemical test of the second embodiment of the application; Figure 10 is a microstructure 100X tissue map of the forge physical and chemical test of the third embodiment of the application; Figure 11 is a microstructure 500X tissue map of the forge physical and chemical test of the third embodiment of the application.

[0053] An aero-engine deep-cylinder thin-walled part forming process, comprising the following steps:

[0054] S100, selecting the diameter and length of the GH4169 rod blank according to the size requirement of the deep-cylinder thin-wall part to be formed;

[0055] S200, preheating the blank in a heating furnace at a preheating temperature of 800±10 DEG C and holding for 168-212 min;

[0056] S300, heating the blank after preheating and holding to (980-1030) ±20 DEG C, and then holding for 101-228 min;

[0057] S400, sequentially performing upsetting, square elongation, round rolling, upsetting and punching on the blank after heating in the free forging hammer equipment;

[0058] S500, rough turning the inner hole of the blank to a preset forming size;

[0059] S600, reheating the blank after rough turning by preheating at a preheating temperature of 800±10 DEG C and holding for 64-104 min, and then heating to a heating temperature of 960-1050 DEG C and holding for 39-95 min;

[0060] S700, expanding the hole of the blank after reheating in the free forging hammer to obtain a GH4169 load-cylinder forging;

[0061] S800, performing solid solution heat treatment on the forging after expanding the hole;

[0062] S900, performing physical and chemical tests on the forging after solid solution heat treatment, and then rough turning the forging to a specified size, and then performing ultrasonic inspection on the forging after rough turning to check whether it is qualified.

[0063] The forming process of the deep-cylinder thin-wall part of the aviation engine according to the application is aimed at the GH4169 deep-cylinder thin-wall part, and by optimizing the forming process steps and process parameters, the upper limit of the forming weight of the GH4169 deep-cylinder thin-wall part can be increased by more than 30%. Meanwhile, aiming at the uneven deformation characteristics in the upsetting process, the upsetting, square elongation, round rolling and upsetting steps are performed to make the forging deformation uniform, effectively ensuring the uniformity of the grain structure of the forging. Among them, the square elongation and round rolling are to make the forging bear force in all directions. In addition, the application also provides a selection and calculation method of the striking energy or tonnage of the free forging equipment, which can further improve the forging precision and effectively improve the quality of the product. The application overcomes the problems of difficult punching forming of the forging and easy mixed crystal in the prior art, and has significant economic benefits.

[0064] It should be noted that please refer to Figure 5, the upsetting of the forging piece can be divided into three zones according to the deformation degree, the first zone is the difficult deformation zone, the deformation degree is the smallest, the second zone is the large deformation zone, the deformation degree is the largest, and the third zone is the small deformation zone, the deformation degree is in the middle. Due to the uneven deformation of the forging piece, the grain in the II zone with the largest deformation degree is fine new grain, and the grain in the I zone and the III zone with smaller deformation degree may be in the critical deformation zone, the degree of grain crushing is different, which leads to local coarse grain. The forging piece is mainly subjected to axial compressive stress during upsetting, and the square elongation and rounding make the forging piece subjected to compressive stress in all directions, so that all regions of the forging piece are in the II zone deformation, thereby making the deformation of the forging piece uniform.

[0065] Preferably, in step S400, the striking energy or tonnage of the free forging equipment is selected according to the deformation work required for the forming of the forging piece, and the calculation formula of the upsetting deformation work A required for the upsetting of the blank is as follows:

[0066]

[0067] In the formula, σ S is the true flow stress at the corresponding deformation temperature and speed, unit: MPa; D1 and H1 are the diameter and height of the blank, unit: mm; D2 and H2 are the diameter and height of the blank after upsetting, unit: mm; V is the volume of the forging piece, unit: mm 3 .

[0068] It should be noted that the tonnage of the free forging equipment required is mainly related to the deformation area, the material of the forging piece, the deformation temperature and other factors. The contact area of the forging piece and the tool during upsetting is much larger than that during other deformation steps, and many forging processes are related to upsetting. Therefore, the tonnage of the free forging equipment is usually selected according to the size of the upsetting force. On the forging hammer, since the striking force is not fixed, the tonnage of the free forging equipment should be selected according to the deformation work required for the forming of the forging piece. According to formula (1), the work required for forging can be obtained, and the corresponding forging equipment can be selected.

[0069] Preferably, in step S400, the calculation formula of the striking energy E of the free forging equipment during upsetting is as follows:

[0070]

[0071] In the formula, E is the striking energy required for the free forging equipment, unit: J; η is the striking efficiency, usually η = 0.7-0.9.

[0072] It can be understood that the striking energy E of the free forging equipment can be calculated by formula (2) combined with formula (1), which facilitates the accurate control of the free forging equipment, improves the processing precision, and ensures the quality of the product.

[0073] Preferably, in step S400, the calculation formula of the tonnage G of the forging hammer of the free forging equipment during upsetting is as follows:

[0074]

[0075] wherein g is the acceleration of gravity, g = 9.8 / s 2 ; v is the forging hammer striking speed, usually v = 5-6 m / s.

[0076] It can be understood that the forging hammer tonnage of the free forging equipment can be calculated by formula (3) combined with formula (1), and the key operating parameters of the free forging equipment are obtained, so as to ensure high-quality forging of the product.

[0077] It should be noted that the relationship between the forging hammer tonnage G and the weight m of the forging of the free forging equipment under different working conditions can also be derived by formula (3) and formula (1), for example, when the forging hammer striking speed is v = 5.5 m / s and the striking efficiency is η = 0.8, then

[0078]

[0079] The relationship between the forging hammer tonnage G and the weight m of the forging can be derived as follows:

[0080]

[0081] wherein ρ is the density of the corresponding material of the forging.

[0082] Therefore, the greater the weight m of the forging, the greater the forging hammer tonnage G required for the upsetting of the forging. Since the diameter D2 and the height H2 of the blank after upsetting are unchanged, the flow stress σ S is a constant at a constant deformation temperature and speed, and when the forging hammer tonnage G is unchanged, the weight m of the forging increases with the decrease of H1 and the increase of D1. Therefore, in the case of a determined forging equipment, in order to increase the forming weight of the forging, the diameter D1 of the blank can be increased, and the height of the blank can be reduced, that is, the height-diameter ratio of the blank is reduced.

[0083] The height-diameter ratio of the GH4169 forging is generally 1.0-2.0, and in order to increase the upper limit of the forming weight of the forging by 30%, the height-diameter ratio of the GH4169 forging is further optimized to 1.0-1.5 in the present application.

[0084] For example, the blank size is Φ160mm*288mm, and the size of the forging after upsetting is Φ234mm*135mm, and formula (5) is substituted as follows:

[0085]

[0086] After optimizing the height-diameter ratio of the blank, the blank size is Φ180mm*228mm, and the size of the forging after upsetting is Φ234mm*135mm, and formula (5) is substituted as follows:

[0087]

[0088] m2 is 32.8% higher than m1, and it can be seen that the upper limit of the forming weight of the GH4169 deep cylinder thin-walled part can be increased by more than 30% by optimizing the height-diameter ratio (1.0-1.5) without changing the weight of the forging.

[0089] Preferably, in step S400, the blank is transferred from the heating furnace to the free forging equipment for forging, and the transfer time should not exceed 15s.

[0090] It can be understood that, in order to reduce the heat loss of the blank as much as possible, the transfer time between the blank being transferred from the heating furnace to the free forging equipment should be as short as possible to ensure that the blank is forged within a suitable temperature range. By stipulating that the transfer time is less than 15s in the present application, the heat loss of the blank can be ensured to be within an acceptable range, facilitating the operation guidance for workers.

[0091] Preferably, in step S400, attention should be paid to the temperature of the forging during the forging process on the free forging hammer equipment, and the temperature of the forging is detected by an optical pyrometer or an infrared temperature detector, and the final forging temperature of the forging should not be lower than 900℃.

[0092] It can be understood that, in order to ensure the effect of forging and reduce the influence of temperature loss or temperature instability of the blank on the performance of the final product, the present application stipulates that the temperature of the forging is detected by an optical pyrometer or an infrared temperature detector during the forging process, so as to ensure that the final forging temperature of the forging is not lower than 900℃, thereby ensuring the final forging quality.

[0093] Preferably, in step S400, the blank should be continuously rotated around the axis of the blank during the upsetting process, and the blank is flipped up and down when the upsetting process is half completed.

[0094] It can be understood that the continuous rotation of the blank around the axis of the blank during the upsetting process and the flipping up and down once during the upsetting process can improve the uniformity of product processing and are beneficial to improving the consistency of the performance of the product in all parts. Flipping up and down once during the upsetting process is considered in view of the deformation characteristics of GH4169, which can prevent the lower head from being cooled too quickly due to heat absorption and thus causing the deformation resistance to increase.

[0095] Preferably, in step S800, the forging is put into the heating furnace when the temperature of the forging is ≤780℃, the heating temperature is (770℃-790℃)±10℃, the temperature is kept for 2h-4h, the temperature is raised to (960℃-980℃)±10℃ with the furnace, the temperature is kept for 2h-2.5h, and then the forging is oil-cooled.

[0096] It can be understood that, in step S800, the holding time of each heating section is extended to at least 2h or more, which can ensure the stability of the performance of the forging and reduce the influence of too rapid temperature change on the performance of the forging.

[0097] Example 1

[0098] 1, the bar size is Φ160mm*288mm, weight m = 47.8kg, height diameter ratio 1.8, the size of the forging after upsetting: Φ234mm*135mm, these data into equation (1) can be obtained: A = 6283.5σ S , so the work required for the forging upsetting. A = 6283.5σ S into equation (4) can be obtained: G = 510.9σ S , so as to determine the corresponding tonnage of forging equipment.

[0099] Bar size is Φ180mm*228mm, weight m = 47.8kg, height diameter ratio 1.27, the size of the forging after upsetting: Φ234mm*135mm, these data into equation (1) can be obtained: A = 4731σ S , so as to determine the corresponding tonnage of forging equipment. A = 4731σ S into equation (4) can be obtained: G = 385σ S , so the work required for the forging upsetting.

[0100] σ S The flow stress is a constant value under the same conditions, so the forging upsetting ratio is reduced from 1.8 to 1.27, the forging upsetting deformation work is reduced by 32.8%.

[0101] 2, the blank is placed in the heating furnace.

[0102] Bar ≤800℃ into the furnace heating, preheating: heating temperature 800±10℃, holding time 188~232min, after heating to: (980~1030)±20℃, holding time 113~258min.

[0103] 3, the heated blank is subjected to upsetting, four square elongation, rounding, upsetting, punching on the free forging hammer

[0104] Among them, the upsetting: the blank is upset to 135±3mm of forming height, the blank should be continuously rotated around the blank axis during upsetting, the blank should be turned up and down once when the upsetting is to 182±5mm, that is, the blank is turned up and down once again in the middle of the upsetting process, to prevent the lower head from being cooled too fast due to heat absorption and causing deformation resistance to increase;

[0105] Punching: using Φ90, taper 3° punch to punch first positive punching (L = 100) and then reverse punching (L = 130).

[0106] 4, rough turning the inner hole of the blank to the specified size

[0107] Rough turning the inner hole size to Φ120±1mm.

[0108] 5. The billet is heated by re-melting.

[0109] The billet is heated by re-melting.

[0110] 6. The re-melted billet is expanded on a free forging hammer.

[0111] The Φ110 core rod is used for expansion, and attention is paid to correction and uniform rotation during expansion. The minimum wall thickness of the forged piece is noted during expansion, and the forged piece is air-cooled after expansion.

[0112] 6. The forged piece is subjected to solid solution heat treatment.

[0113] The forged piece is heated to (770-790) ±10°C, and is kept at this temperature for 2-4 hours. The forged piece is then raised to (960-980) ±10°C, and is kept at this temperature for 2-2.5 hours. The forged piece is then oil-cooled.

[0114] 8. The solid-solution-treated forged piece is sampled for physical and chemical testing.

[0115] 9. The forged piece that passes the physical and chemical testing is subjected to rough turning.

[0116] 10. The rough-turned forged piece is subjected to ultrasonic inspection.

[0117] The GH4169 load-bearing cylinder is thus completed.

[0118] The physical and chemical testing high-magnification microstructure of the forged piece subjected to the conventional forming process is shown in Figure 1 , and the forged piece has uneven grain structure and obvious mixed grains.

[0119] The physical and chemical testing high-magnification microstructure of the forged piece subjected to the forging, square elongation, rounding, upsetting, punching, rough turning and expansion steps is shown in Figure 6 and Figure 7 , and the forged piece has uniform grain structure.

[0120] Example Two

[0121] 1. The bar stock has a size of Φ160mm*228mm, a height-to-diameter ratio of 1.43, and a weight of m=37.8kg. After upsetting, the forged piece has a size of Φ204mm*140mm. These data are substituted into Formula ① to obtain A=2620σ. S Thus, the work required for forging upsetting can be obtained. Substituting A=2620σ S into Formula ④ gives G=213σ S , and thus the corresponding tonnage of the forging equipment is determined.

[0122] 2. The billet is heated in a heating furnace.

[0123] Bar ≤800 ℃ into the furnace heating, preheating: heating temperature 800 ± 10 ℃, holding time 168 ~ 212 min, after heating to: (980 ~ 1030) ± 20 ℃, holding time 101 ~ 228 min.

[0124] 3. The heated blank on the free forging hammer is upset, square elongated, rounded, upset, punched.

[0125] Upset: the blank is upset to 140 ± 3 mm, and the blank should be continuously rotated around the blank axis during the upsetting process, and the blank should be turned up and down once when it is upset to 180 ± 5;

[0126] Punching: use Φ90, taper 3° punch (special punch) to punch (L = 100) first and then reverse punch (L = 130).

[0127] 4. Rough turning the inner hole of the blank to the specified size

[0128] The inner hole size is turned to Φ120 ± 1 mm.

[0129] 5. The blank is reheated.

[0130] The blank is ≤800 ℃ into the furnace heating, preheating: heating temperature 800 ± 10 ℃, holding time 51 ~ 105 min, after heating to: (980 ~ 1030) ± 20 ℃, holding time 31 ~ 87 min.

[0131] 6. The reheated blank is expanded on the free forging hammer.

[0132] Use Φ110 core rod to expand, pay attention to correction during expansion, and rotate uniformly, pay attention to the minimum wall thickness of the forging during expansion, and air cool after expansion.

[0133] 7. The forged piece is subjected to solid solution heat treatment.

[0134] The forging ≤780 ℃ into the furnace, (770 ℃ ~ 790 ℃) ± 10 ℃, holding 2h ~ 3h, furnace to (960 ℃ ~ 980 ℃) ± 10 ℃, holding 2h ~ 2.5h, forging oil cooling.

[0135] 8. The solid solution of the forged piece is sampled for physical and chemical test.

[0136] 9. The forged piece that passes the physical and chemical test is rough turned.

[0137] 10. The forged piece after rough turning is subjected to ultrasonic inspection.

[0138] Thus the preparation of GH4169 load cylinder is completed.

[0139] The forging piece is subjected to the forging steps of upsetting, square lengthening, round, upsetting, punching, rough turning, and hole expanding. The high-magnification microstructure of the forging piece is shown in the following table Figure 8 and Figure 9 The forging piece has uniform grain size.

[0140] Example Three

[0141] 1. The size of the bar is Φ180mm*186mm, the height-diameter ratio is 1.03, the weight m is 39kg, and the size of the forged piece after upsetting is Φ211mm*135mm. These data are substituted into formula ① to obtain A=1865σ S , and thus the work required for the upsetting forging can be obtained. Substituting A=1865σ S into formula ④, G=152σ S is obtained, and thus the tonnage of the corresponding forging equipment is determined.

[0142] 2. The blank is heated in a heating furnace.

[0143] The bar is heated in the furnace at ≤800℃, the preheating temperature is 800±10℃, the holding time is 182-230min, the temperature is then raised to (980-1030)±20℃, and the holding time is 110-255min.

[0144] 3. The heated blank is subjected to upsetting, square lengthening, round, upsetting, and punching on a free forging hammer, and a special punch is used for punching.

[0145] Upsetting: the blank is upset to 135±3mm, and the blank should be continuously rotated around the blank axis during the upsetting. When the blank is upset to 160±5, the blank should be turned upside down once.

[0146] Punching: a punch with a diameter of Φ90 and a taper of 3° is used for punching (special punch). The punch is first used for forward punching (L=100) and then for reverse punching (L=130).

[0147] 4. The blank is rough-turned to the specified size of the inner hole.

[0148] The size of the inner hole is turned to Φ120±1mm.

[0149] 5. The forged piece is subjected to solid solution heat treatment.

[0150] The forged piece is put into the furnace at ≤780℃, the temperature is (770-790)±10℃, the holding time is 3-4h, the temperature is raised to (960-980)±10℃ with the furnace, the holding time is 2-2.5h, and the forged piece is oil-cooled.

[0151] 6. The forged piece after the solid solution is sampled for physical and chemical tests.

[0152] 7. The forged piece that passes the physical and chemical tests is rough-turned.

[0153] 8. The forged piece after the rough turning is subjected to ultrasonic inspection.

[0154] At this point, the GH4169 force cylinder preparation is completed.

[0155] The forging piece is subjected to the forging steps of drawing, elongating, rolling, upsetting, punching, rough turning, and hole expanding, and the high-magnification microstructure diagram of the forging piece is shown in Figure 10 and Figure 11 The forging piece has uniform grain structure.

[0156] According to another aspect of the present application, an aero-engine deep-cylinder thin-wall piece forming tool is also provided, which is applied to the aero-engine deep-cylinder thin-wall piece forming process. The aero-engine deep-cylinder thin-wall piece forming tool comprises a forward punch 1 and a backward punch 2. The forward punch 1 is connected to a punching device to punch the deep-cylinder thin-wall piece blank through the forward punch 1. The backward punch 2 is connected to the punching device to punch out the bottom sheet of the deep-cylinder thin-wall piece blank through the backward punch 2.

[0157] The aero-engine deep-cylinder thin-wall piece forming tool of the present application also has the beneficial effects described above. Meanwhile, the forming tool of the present application can also achieve the effect of more easily punching out the punching bottom sheet, and has a simple and efficient tool structure and is very convenient to use, which is conducive to further improving the processing efficiency.

[0158] Preferably, as shown in Figure 3 and Figure 4 The forward punch 1 and the backward punch 2 are both conical frustums with a wide upper part and a narrow lower part. The bottom surface and the top surface of the forward punch 1 and the backward punch 2 are both chamfered at the same angle. The minimum diameter of the backward punch 2 is smaller than the diameter of the forward punch 1, and the height of the backward punch 2 is higher than that of the forward punch 1.

[0159] It can be understood that the overall structure of the forward punch 1 and the backward punch 2 is simple and efficient. By designing punches of different sizes and using different ways, the punching bottom sheet can be punched out efficiently, which is conducive to improving the processing efficiency of punching.

[0160] It should be noted that in this document, the terms "comprising", "including", or any other variant thereof are intended to cover non-exclusive inclusions, so that processes, methods, articles, or devices including a series of elements not only include those elements, but also include other elements not explicitly listed, or inherent to such processes, methods, articles, or devices.

[0161] The principles and implementations of the present application are described herein with specific examples. The above examples are only used to help understand the method and its core idea of the present application. The above description is only the preferred embodiments of the present application. It should be pointed out that due to the limited nature of the language expression, there are objectively infinite specific structures, and for ordinary skilled persons in the art, without departing from the principles of the present application, a number of improvements, refinements or changes can be made, or the above technical features can be combined in an appropriate manner. The improvements, refinements, changes or combinations, or the application of the inventive concept and technical solution to other fields without improvement, shall be regarded as the protection of the present application.

Claims

1. A forming process for a deep-cylinder thin-walled part for an aero-engine, characterized in that, Includes the following steps: S100. Select the diameter and length of the GH4169 bar stock according to the size requirements of the deep cylindrical thin-walled parts to be processed and formed. S200. Place the blank in a heating furnace for preheating at a temperature of 800±10℃ and hold for 168~212min. S300. The preheated and heat-preserved blank is heated to (980~1030)±20℃, and then heat-preserved for 101~228min. S400: The heated billet is sequentially upset, drawn into a square shape, rolled, upset again, and punched on a free forging hammer. During the upset process, the billet should continuously rotate around its axis. When the upset is halfway complete, the billet is flipped over. The height-to-diameter ratio of the GH4169 forging is optimized to 1.0–1.

5. The striking energy or tonnage of the free forging equipment is selected based on the deformation work required for forging. The formula for calculating the upset deformation work A required for the billet is as follows: In the formula: σ S The actual flow stress at the corresponding deformation temperature and speed is expressed in MPa; D1 and H1 are the diameter and height of the billet, in mm; D2 and H2 are the diameter and height of the billet after upsetting, in mm; V is the volume of the forging, in mm. 3 ; S500: Roughly machine the inner hole of the blank to the preset forming size; S600. The billet completed by roughing is reheated in the furnace. First, it is preheated at a temperature of 800±10℃ and held for 64 to 104 minutes. Then, it is heated to a temperature of 960 to 1050℃ and held for 39 to 95 minutes. S700: The blank that has been reheated in the furnace is enlarged on a free forging hammer to obtain the GH4169 load-bearing cylinder forging; S800: The forging with enlarged holes is subjected to solution heat treatment; S900. Forgings that have undergone solution heat treatment are sampled and subjected to physical and chemical tests. Forgings that pass the physical and chemical tests are then rough-machined to the specified dimensions. After rough machining, the forgings are subjected to ultrasonic testing to determine whether they are qualified.

2. The forming process for a deep-cylinder thin-walled part of an aero-engine according to claim 1, characterized in that, In step S400, during upsetting, the calculation formula for the impact energy E of the free forging equipment is as follows: In the formula: E is the impact energy required by the free forging equipment, in J; η is the impact efficiency, usually taken as η = 0.7 to 0.

9.

3. The forming process for a deep-cylinder thin-walled part of an aero-engine according to claim 1, characterized in that, In step S400, during upsetting, the calculation formula for the forging hammer tonnage G of the free forging equipment is as follows: In the formula: g is the acceleration due to gravity, g = 9.8 / s² 2 v is the striking speed of the forging hammer, usually taken as v = 5~6m / s.

4. The forming process for a deep-cylinder thin-walled part of an aero-engine according to claim 1, characterized in that, In step S400, the billet is transferred from the heating furnace to the free forging equipment for forging, and the transfer time shall not exceed 15 seconds.

5. The forming process for a deep-cylinder thin-walled part of an aero-engine according to claim 1, characterized in that, In step S400, attention should be paid to the temperature of the forging during the forging process on the free forging hammer equipment. The temperature of the forging should be detected by an optical pyrometer or an infrared thermometer. The final forging temperature of the forging should not be lower than 900℃.

6. The forming process for a deep-cylinder thin-walled part of an aero-engine according to claim 1, characterized in that, In step S800, when the forging is ≤780℃, it enters the heating furnace and is heated to (770℃~790℃)±10℃. It is held for 2h~4h, and then the furnace temperature is raised to (960℃~980℃)±10℃ and held for 2h~2.5h. After that, the forging is oil cooled.

7. A forming fixture for aero-engine deep-cylinder thin-walled parts, characterized in that, The forming fixture for deep-cylinder thin-walled parts of aero-engines is applied to the forming process of deep-cylinder thin-walled parts of aero-engines as described in any one of claims 1-6. The forming fixture for deep-cylinder thin-walled parts of aero-engines includes a positive punch (1) and a negative punch (2). The positive punch (1) is used to connect to a punching device to punch the deep-cylinder thin-walled part blank through the positive punch (1). The negative punch (2) is used to connect to a punching device to punch out the bottom sheet of the deep-cylinder thin-walled part blank through the negative punch (2).

8. The forming fixture for aero-engine deep-cylinder thin-walled parts according to claim 7, characterized in that, Both the forward punch (1) and the reverse punch (2) are truncated cone structures that are wider at the top and narrower at the bottom. The bottom and top surfaces of both the forward punch (1) and the reverse punch (2) are chamfered at the same angle. The minimum diameter of the reverse punch (2) is smaller than the diameter of the forward punch (1), and the height of the reverse punch (2) is higher than that of the forward punch (1).

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