A forging process for high-temperature alloy disc-shaft integrated turbine rotor die forgings

Abstract

The present invention discloses a forging process for a high-temperature alloy disc-shaft integrated turbine rotor die forging, comprising the steps of determining the size of a bar stock; performing a first rough turning on the bar stock; preheating the rough-turned blank, applying a glass powder lubricating protective agent on the blank surface, charging the blank into a furnace for heating, quickly wrapping the blank with heat-insulating cotton after the blank is removed from the furnace, and reheating the blank; forging the heated blank into a blank using a single-fire forming method; performing a second rough turning; applying a glass powder lubricating protective agent on the blank surface, charging the blank into a furnace, performing pre-forging heating on the blank; performing final forging heating on the pre-forging heated blank; performing final forging heating on the final forging heated blank to obtain a forging; performing a third rough turning on the forging; and performing a solution-aging heat treatment on the forging to obtain a disc-shaft integrated turbine rotor die forging. The present invention can forge disc-shaft integrated rotor forgings for use in aerospace engines with stable mechanical properties and uniform structure.

Description

Technical Field

[0001] The invention belongs to the technical field of aerospace engine rotor forging, and relates to a forging process for a hard-to-deform nickel-based high-temperature alloy disc-shaft integrated turbine rotor die forging. Background Art

[0002] The turbine rotor, a key component of a turbopump, is made of GH4586 nickel-based superalloy. Driven by high-speed combustion gases, the turbine rotor in certain liquid rocket engines rotates at speeds reaching 30,000 rpm and temperatures as high as 1,123 K. Due to the high temperature, high pressure, intense vibration, and corrosion experienced by the rotor, the disk, spokes, and blades are subject to complex stresses, including both tensile and torsional stresses. Furthermore, each startup and shutdown process results in high-stress, low-cycle fatigue. Therefore, the engine places extremely high demands on rotor performance and stability.

[0003] This type of turbine rotor features an integrated disc-shaft structure, meaning the rotor's drive shaft and disc are integrated. The disc's outer diameter is approximately seven times the shaft's. Direct machining of rods would result in significant waste of raw materials, so integral forging is recommended. However, the GH4586 alloy's high alloying degree, strong deformation resistance, sensitivity to temperature and strain rate, and narrow forging window make forging difficult. Therefore, the proper selection of turbine rotor forging process parameters is crucial. High-temperature alloy disc-shaft forgings with large outer diameter ratios cannot be forged in a single forging process; multiple forging cycles involving shaft extraction and disc forming are required. However, mature process parameters are not yet available for the forging process of the nickel-based high-temperature GH4586 alloy. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above-mentioned defects and provide a forging process for high-temperature alloy disc-shaft integrated turbine rotor die forgings, which solves the technical problem that high-temperature alloy disc-shaft integrated forgings with a large aspect ratio are difficult to form. The present invention can forge disc-shaft integrated rotor forgings with stable mechanical properties and uniform structure for use in aerospace engines.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] A forging process for a high-temperature alloy disc-shaft integrated turbine rotor die forging, comprising:

[0007] S1 Determine the size of the bar material according to the size requirements of the required disc-shaft integrated turbine rotor die forgings;

[0008] S2 performs the first rough turning on the bar to obtain the rough turned blank;

[0009] S3: After preheating the rough-turned blank, apply glass powder lubricant and protective agent on the surface of the blank. After the glass powder lubricant and protective agent is dried, the blank is loaded into the furnace for heating. After the blank is taken out of the furnace, it is wrapped with insulation cotton and returned to the furnace for heating.

[0010] S4: The heated blank with the insulation cotton is forged by a double-die tumbling and fire forming method;

[0011] S5 performs a second rough turning on the forged billet;

[0012] S6: Brush glass powder lubricating protective agent on the surface of the blank after the second rough turning. After the glass powder lubricating protective agent is dried, the blank is loaded into the furnace and pre-forged and heated.

[0013] S7 pre-forging the pre-heated billet;

[0014] S8: The pre-forged billet is loaded into the furnace for final forging heating;

[0015] S9 performs final forging on the billet after final forging heating to obtain a forging;

[0016] S10 performs the third rough turning on the forging;

[0017] S11 performs a solution-aging heat treatment on the forging after the third rough turning to obtain a disk-shaft integrated turbine rotor die forging.

[0018] Furthermore, in step S2, the blank obtained after the first rough turning has a shape that is thin at both ends and thick in the middle, the middle and both ends are cylindrical, the edges and connections of the middle and both ends are rounded, and the middle and both ends are respectively a disk portion and a shaft portion;

[0019] In step S5, the second rough turning method is to rough turn the shaft portion of the blank according to a taper of 7 to 10 degrees, and make a smooth transition between the shaft portion and the disk portion of the blank;

[0020] In steps S7 and S9, the disk portion of the blank is pre-forged and final forged;

[0021] In step S10, the method of performing a third rough turning on the forging is to remove the machining allowance in the forging, remove 1 to 2 mm of surface cold structure, and form a fillet at the connection between the disk and the shaft of the forging. The disk and shaft of the resulting forging respectively correspond to the wheel disk and shaft of a turbine rotor die forging with a disk and shaft.

[0022] Furthermore, in step S3, the rough-turned blank is preheated at 50-150° C. for 10-30 minutes, a glass powder lubricant and protective agent is applied to the surface of the blank, and after the glass powder lubricant and protective agent is dried, the furnace temperature is raised to 950-980° C., the blank is loaded into the furnace, and kept at 950-980° C. for 120±10 minutes. After the holding period, the temperature is raised to 1080-1100° C. with the furnace, and after reaching the temperature, the blank is taken out of the furnace and covered with insulation cotton. After the covering is completed, the blank covered with insulation cotton is returned to the furnace, heated to 1080-1100° C., and kept at this temperature for not less than 90 minutes and not more than 140 minutes.

[0023] In step S4, the temperature of the die is not less than 250±50°C when forging starts, the temperature of the die is ≥980°C when forging ends, and the deformation of the shaft portion of the blank is 20-40%;

[0024] After the blank is returned to the furnace for reheating in step S3, the time from when the blank is taken out of the furnace to when the blank is transferred to the mold does not exceed 30 seconds.

[0025] Furthermore, in step S6, the method for pre-forging and heating the billet is to raise the furnace temperature to 950-980°C, charge the billet into the furnace, and keep it at 950-980°C for 120±10 minutes. After the insulation is completed, the temperature is raised to 1085±10-1100±10°C with the furnace and kept for not less than 100 minutes and not more than 200 minutes.

[0026] In step S7, the blank is pre-forged using a forging die on an electric screw press. The temperature of the forging die is not less than 250±50°C when forging starts and is ≥980°C when forging ends. The deformation of the blank disc is between 20% and 60%.

[0027] After the pre-forging heating of the billet is completed in step S6, the time from the billet being taken out of the furnace to the billet being transferred to the forging die does not exceed 30 seconds.

[0028] Furthermore, in step S8, the method of final forging heating is to raise the temperature of the billet to 1100±10-1110±10°C along with the furnace temperature and keep the temperature therein, wherein the holding time is greater than or equal to 40 minutes and less than or equal to 200 minutes;

[0029] In step S9, when the final forging is performed on the heated billet, the temperature of the forging die is not less than 250±50°C at the start of forging, and the temperature of the forging die is ≥980°C at the end of forging, and the deformation of the billet disc is between 25% and 70% during final forging;

[0030] After the final forging heating of the billet is completed in step S8, the time from the billet being taken out of the furnace to the billet being transferred to the forging die does not exceed 30 seconds.

[0031] Furthermore, the final forging in step S9 and the pre-forging in step S7 use the same forging die, the forging die including an upper die and a lower die, which are combined to form a die cavity, the die cavity including a shaft cavity and a disc cavity, the disc cavity having the same shape as the wheel disc of the final hot forging after adding machining allowance, and the shaft cavity having the same shape as the shaft portion of the blank obtained by the second rough turning; the dimensions of the hot forging can be converted from the forging drawing according to the thermal shrinkage rate;

[0032] The circumferential surface of the disk cavity is provided with an outward-facing, closed, conical flash-shaped cavity. A symmetrical inward depression is formed at a distance R / 2 from the center of the cavity, with a single-sided depression of 2 to 3 mm. R is the radius of the cavity, and the distance here refers to the distance between the center of the cavity and the lowest point of the depression. The conical flash-shaped cavity provided by the present invention is a throatless cavity, which helps improve the unit stress structure during the disk deformation process, ensuring a good metallographic grain structure during final forging and preventing the outer epitaxial part from contacting the mold wall first during disk forming, thereby changing the flow pattern of the disk's external radiation. The single-sided depression of 2 to 3 mm can increase the alloy deformation from the disk core to the disk R / 2, achieving the purpose of grain refinement in the process.

[0033] Furthermore, the glass powder lubricating and protective agent is FR35 glass powder lubricating and protective agent;

[0034] The thickness of the insulation cotton is 5 to 15 mm;

[0035] The aspect ratio of the bar is 2 to 3:1.

[0036] Furthermore, in step S7, an underpressure ring is used to control the pre-forging deformation during pre-forging, and in step S9, the underpressure ring is removed during final forging. The underpressure ring can be matched with the corresponding mold, and the thickness of the underpressure ring can be designed according to the required deformation amount.

[0037] Furthermore, in step S11, the method of performing the solution-aging heat treatment is:

[0038] Solution treatment stage: put the forging into the furnace at 650±10℃, heat it up to 800±10℃ and keep it for 2~3 hours, heat it up to 950±10℃ and keep it for 2~3 hours, heat it up to 1080±10℃ and keep it for 5~6 hours, then cool it in air and oil at room temperature after taking it out of the furnace;

[0039] Aging treatment stage: Place the forgings into the furnace at 650±10℃, heat up to 760±10℃ and keep warm for 16 to 20 hours, then air cool after taking them out of the furnace.

[0040] Furthermore, it also includes testing the surface quality, metallographic structure and mechanical properties of the disc-shaft integrated turbine rotor die forgings, and forgings that meet the testing standards are regarded as qualified forgings;

[0041] The standards for surface quality inspection include: no defects on the surface of forgings, including cracks, folds, delaminations, inclusions or voids;

[0042] The standards for metallographic structure testing include: grain purity is assessed according to the Class B rating chart specified in GB / T14999.5; low-magnification structure inspection shows no visible defects, including cracks, pinholes, slag inclusions, or porosity;

[0043] The standards for mechanical properties testing are as follows:

[0044]

[0045] Among them, Rm, Rp0.2, A, Z, impact ak, σ, and τ are tensile strength, yield strength, elongation, cross-sectional shrinkage, impact toughness, endurance stress, and endurance time, respectively.

[0046] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0047] (1) The present invention proposes a method for synchronously drawing the shafts at both ends for forgings with a large outer diameter ratio by designing a double-jointed die. This method can effectively reduce the number of forming cycles required for drawing the shaft, which is beneficial to the control of the internal structure of the shaft of the forging.

[0048] (2) During the second rough turning process of the present invention, the shaft portions at both ends of the blank have an inclination of 7 to 10 degrees, forming a gradient deformation structure perpendicular to the disk portion, ensuring that the pre-forging process increases the deformation of the root core portion at the transition between the disk and the shaft, forming a gradient deformation during the metal flow process;

[0049] (3) The pre-forging and final forging of the present invention are performed on an electric screw press using the same set of dies. The closed dimension at the disk R / 2 is reduced by 2 to 3 mm during die design. This is mainly to increase the alloy deformation from the disk core to the disk R / 2, thereby achieving the goal of refining the grain structure in the process. At the same time, a closed cavity with an inclined throat and no burr should be added to the periphery of the die disk, which is beneficial to improving the unit stress structure during the deformation process of the die, ensuring that a good metallographic grain structure is obtained during final forging, and avoiding the situation in which the outer epitaxial part contacts the die wall first during die forming, thereby changing the flow pattern of the outer radiation of the die.

[0050] (4) The present invention prevents oxidation of the blank by applying glass lubricant and soft coating process during the blank making process, reduces the depletion of alloy elements on the blank surface during the heating process, and secondly reduces the chilling effect of the die on the forging and has a certain heat preservation effect, thereby increasing the initial and final forging temperatures of the blank, greatly reducing the friction during the forging process, and effectively improving the quality of the finished forging.

[0051] (5) In the die forging process, the present invention removes the soft sleeve and only applies the glass lubricant through the reasonable design of the die in (3), thereby increasing the fluidity of the alloy forging and preventing large grains with incomplete grain boundaries caused by temperature change effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is a schematic diagram of the first rough turning of the present invention;

[0053] Figure 2 This is a schematic diagram of the second rough turning process of the present invention;

[0054] Figure 3 is a schematic diagram of a forging of the present invention;

[0055] Figure 4 This is a schematic diagram of the third rough turning of the present invention;

[0056] Figure 5 Schematic diagram of the blank making tooling of the present invention; wherein (a) is a front view and (b) is a side view;

[0057] Figure 6 Schematic diagram of the forging die of the present invention; wherein, (a) is an outline view, (b) is a cross-sectional view, (c) is a top view, and (d) is a partial view. DETAILED DESCRIPTION

[0058] The following detailed description of the present invention will make the features and advantages of the present invention more clear and explicit.

[0059] The word "exemplary" is used exclusively herein to mean "serving as an example, example, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise indicated.

[0060] The present invention belongs to the technical field of rotor forging for aerospace engines, and relates to a forging process for a hard-to-deform nickel-based high-temperature alloy disc-shaft integrated turbine rotor die forging, and belongs to the technical field of aerospace engine turbine rotor forging. The process steps are as follows: blanking, first rough turning, blank heating, blank making, second rough turning, pre-forging heating, pre-forging, third rough turning, final forging heating, final forging, heat treatment and final inspection. The engine turbine rotor forged by the forging process of the present invention has a complete rotor forging shape, good surface quality, stable mechanical properties of the forging, large performance margins, uniform organization, and metallographic structure that meets design requirements. The present invention can forge rotor forgings for aerospace engines with stable mechanical properties and uniform organization, and is a hard-to-deform alloy aerospace engine turbine rotor forging process.

[0061] A forging process for a hard-to-deform nickel-based high-temperature alloy disk-shaft integrated turbine rotor die forging comprises the following steps:

[0062] (1) Cutting: According to the required part size requirements, the height-to-diameter ratio of GH4586 high-temperature alloy bar is (2-3):1;

[0063] (2) First rough turning: After the bar is rough-cut and exposed to light, the rough turning size of the shaft is calculated according to the deformation of the shaft. Finally, the bar is rough-turned into a shape with thin ends and thick middle. The sharp corners are rounded R2. There are no pinholes on the two end surfaces and no obvious cutting marks on the surface.

[0064] (3) Blank heating: Preheat the rough-turned blank at (50-150)℃ for 10-30min, evenly brush the surface with glass powder lubricant and protective agent, and after the glass powder protective agent is dry, raise the furnace temperature to (950-980)℃ and start loading the furnace. After reaching the temperature, keep it warm for 120±10min. After the end of the (950-980)℃ insulation, raise the temperature to (1080-1100)℃ with the furnace. After reaching the temperature, take the blank out of the furnace and quickly wrap the circumference and end (i.e., the middle and both ends) of the blank with high-temperature cotton. After the wrapping is completed, return the furnace to heat to (1080-1100)℃ and keep it warm for not less than 90min. The longest insulation time of the blank shall not exceed 140min. The maximum loading capacity is ≤20 pieces.

[0065] (4) Blank making: The temperature of the die must not be lower than 250±50℃ when starting forging. The deformation of the shaft (both ends) should be 20-40% in one fire. The end temperature of forging should be ≥980℃. The transfer time (the time from the blank being taken out of the furnace to the blank being transferred into the die) should not exceed 30s.

[0066] (5) Second rough turning: The shafts at both ends of the blank are rough turned at a taper of 7-10°. The rest of the surface is polished and has a smooth transition. No pinholes are allowed on the two end surfaces, and no obvious cutting marks are allowed on the surface. Black skin is allowed on some parts of the blank.

[0067] (6) Pre-forging heating: Brush the surface of the blank with glass powder lubricant and protective agent evenly. After the glass powder protective agent is dry, the forging must be placed in the effective heating zone of the furnace for heating. The furnace temperature rises to (950-980)℃ and the furnace is loaded. After reaching the temperature, it is kept warm for 120±10min. After the (950-980)℃ insulation is completed, the temperature is raised to (1085-1100)±10℃ and the temperature is kept warm for not less than 100min. The longest insulation time of the blank shall not exceed 200min. The maximum loading capacity is ≤20 pieces. The temperature reaching a certain temperature means that the temperature reaches a certain temperature.

[0068] (7) Pre-forging: Pre-forging is performed using a die on an electric screw press (the die cavity is designed according to the final hot forming size of the forging). The die temperature must not be lower than 250±50℃ when forging begins, the transfer time (the time it takes to transfer the billet from the furnace to the die) must not exceed 30s, the forging end temperature must be ≥980℃, and the deformation must be between 20% and 60%;

[0069] (8) Final forging heating: Forgings must be placed in the effective heating zone of the furnace. The hot state is returned to the furnace and the temperature is raised to (1100~1110)±10℃. After reaching (1100~1110)±10℃, the temperature must be kept at least 40min. The longest holding time of the billet shall not exceed 200min. The maximum loading capacity is ≤20 pieces.

[0070] (9) Final forging: Final forging is performed using a die on an electric screw press. The die temperature must not be lower than 250±50°C when forging begins, the transfer time must not exceed 30s, the final forging temperature must be ≥980°C, and the deformation must be between 25% and 70%. The deformation here is the ratio of the disc dimensions before and after final forging.

[0071] (10) Third rough turning: The forging after final forging is machined symmetrically along the center line with equal allowance, removing 1-2 mm of surface cold structure, and rounding the sharp corners with R2 fillet. No obvious cutting marks are allowed on the surface, and black skin is allowed on some parts of the blank.

[0072] (11) Heat treatment: solution-aging heat treatment is adopted;

[0073] (12) Inspection: Check the size, surface quality, metallographic structure and mechanical properties of the rotor forgings.

[0074] In a specific embodiment, in step (3), the glass powder lubricating protective agent is FR35 glass powder lubricating protective agent, and the thickness of the thermal insulation cotton used for the sheath is 5 to 15 mm.

[0075] In a specific embodiment, in the heating step, the heating equipment is an electric furnace for heating.

[0076] In a specific embodiment, in step (7), an underpressure ring is required to be added during pre-forging to control the pre-forging deformation; in step (9), the underpressure ring is removed during final forging;

[0077] In a specific embodiment, the pre-forging and final forging of the present invention are performed using the same set of dies on an electric screw press. Figure 6The mold includes an upper mold 1 and a lower mold 2. The upper mold 1 and the lower mold 2 are combined to form a mold cavity 3. When designing the mold, the closed size at the disk R / 2 is reduced by (2 to 3) mm, mainly to increase the alloy deformation from the disk core to the disk R / 2, so as to achieve the purpose of refining the microstructure grain in the process. At the same time, a closed cavity with an inclined shape and no throat flash should be added to the periphery of the mold disk, which is beneficial to improving the unit stress structure of the disk deformation process, ensuring a good metallographic grain structure during the final forging, and avoiding the outer extension of the disk from contacting the mold wall first during the forming of the disk, which changes the flow law of the external radiation of the disk.

[0078] In a specific embodiment, in step (11), the heat treatment method is as follows: solution treatment stage: put into the furnace at 650°C, heat up to 800°C with the furnace and keep warm for 2 hours, heat up to 950°C with the furnace and keep warm for 2 hours, heat up to 1080°C with the furnace and keep warm for 5 hours, take out of the furnace and air cool and then oil cool; aging treatment stage: put into the furnace at 650°C, heat up to 760°C with the furnace and keep warm for 16 hours, and air cool.

[0079] In a specific embodiment, in step (12), the rotor forging size surface quality inspection standard is: no defects such as cracks, folds, delamination, inclusions, and voids are allowed on the forging surface; the metallographic structure inspection standard is: take a test piece for grain size inspection, record the measured results, and evaluate the purity according to the Class B rating chart specified in GB / T14999.5. Under low-magnification structure inspection, no defects such as cracks, pinholes, slag inclusions, and loose traces visible to the naked eye are allowed to exist; the mechanical property energy inspection standard is shown in Table 1.

[0080] Table 1 Mechanical properties required values

[0081]

[0082] Example 1

[0083] This example uses a certain type of liquid rocket engine turbine rotor forging as an example. The glass powder lubricant and protective agent used is FR35, and the insulation coating is approximately 5mm thick. A 3T open die forging hammer is used for blanking, and a 4000T electric screw press is used for pre-forging and final forging. The forging furnace used complies with the requirements of Class III furnaces in GJB904A, with a temperature uniformity of ±10°C and a temperature control accuracy of ±5°C. Each furnace produces ≤20 forgings continuously. The time specified in the process steps is a time range, and the pre-forging process can be controlled within this time range.

[0084] (1) Cutting: According to the required part size requirements, select GH4586 bar material with a specification of Φ100mm and a length of 280mm;

[0085] (2) First rough turning: Press the blank into Figure 1The shape is rough turned, and the sharp corners are rounded to R2;

[0086] (3) Blank making and heating: preheat the rough-turned blank at 100°C for 30 minutes, evenly brush the surface with glass powder lubricant and protective agent, wait for the glass powder protective agent to dry, raise the furnace temperature to 950°C and start loading the furnace, keep it warm for 120 minutes after reaching the temperature, and then raise the temperature to 1080°C with the furnace after the 950°C insulation is completed. After reaching the temperature, the blank is taken out of the furnace and wrapped with high-temperature cotton. After the wrapping is completed, return the furnace and heat it to 1080°C and keep it warm for 100 minutes;

[0087] (4) Blank making: When forging, the temperature of the die must not be lower than 250℃, and the 3T free forging hammer is used. Figure 5 The tooling shown is formed into the required dimensions by one fire, with the shaft deformation of 36%, the final forging temperature ≥ 980℃, and the transfer time not exceeding 30s;

[0088] (5) Second rough turning: Press the blank after forming Figure 2 The shape is rough turned, and black skin is allowed locally on the blank;

[0089] (6) Pre-forging heating: Brush the surface of the blank with glass powder lubricant and protective agent evenly. After the glass powder protective agent is dry, the forging must be placed in the effective heating zone of the furnace for heating. The furnace temperature rises to 980℃ and then starts to load the furnace. After reaching the temperature, keep it warm for 120 minutes. After the end of the 980℃ holding, the temperature is raised to 1095℃ and kept warm for 100 minutes.

[0090] (7) Pre-forging: Used on 4000T electric screw press Figure 6 The mold shown in the figure is pre-forged. When starting forging, the mold temperature must not be lower than 250℃, the transfer time must be ≤20s, the final forging temperature must be ≥980℃, the deformation must be 55%, and the mold cavity must be kept warm after pre-forging.

[0091] (8) Final forging heating: Forgings must be placed in the effective heating zone of the charging furnace. Heat the furnace temperature to 1105℃ and keep it at 1105℃ for 90 minutes;

[0092] (9) Final forging: Use the die on the electric screw press for final forging. The temperature of the die must not be lower than 250℃ when forging, the transfer time must be ≤20s, the final forging temperature must be ≥980℃, the deformation of the disc must be 45%, and the forging after final forging must be as follows: Figure 3 As shown;

[0093] (10) The third rough turning: Press the forging after final forging Figure 4 The shape is machined, and the blank is allowed to have black skin locally;

[0094] (11) Heat treatment: Solution treatment stage: put into furnace at 650℃, heat up to 800℃ and keep warm for 2 hours, heat up to 950℃ and keep warm for 2 hours, heat up to 1080℃ and keep warm for 5 hours, then air cool and oil cool. Aging treatment stage: put into furnace at 650℃, heat up to 760℃ and keep warm for 16 hours, then air cool.

[0095] (12) Inspection: According to the requirements of the final inspection process, the dimensions of the forged turbine rotor forgings shall be inspected. The dimensions of the rotor forgings shall meet the process requirements, the forgings shall be complete in appearance, and there shall be no defects such as cracks, folds, or crushing on the surface. The mechanical properties requirements are shown in Table 2:

[0096] Table 2 Physical and chemical test results of turbine rotor forgings of Example 1

[0097]

[0098] Example 2

[0099] This embodiment takes a certain type of liquid rocket engine turbine rotor forging as an example. The heating equipment, forging equipment and auxiliary equipment used are the same as those in Example 1.

[0100] (1) Cutting: According to the required part size requirements, select GH4586 bar material with a specification of Φ120mm and a length of 282mm;

[0101] (2) First rough turning: Press the blank into Figure 1 The shape is rough turned, and the sharp corners are rounded to R2;

[0102] (3) Blank heating: Preheat the rough-turned blank at 150°C for 20 minutes, evenly brush the surface with glass powder lubricant and protective agent, and after the glass powder protective agent is dry, raise the furnace temperature to 950°C and start loading the furnace. After reaching the temperature, keep it warm for 130 minutes. After the end of the 950°C insulation, raise the temperature to 1085°C with the furnace. After reaching the temperature, take the blank out of the furnace and quickly wrap it with high-temperature cotton. After the wrapping is completed, return the furnace to heat it to 1085°C and keep it warm for 90 minutes.

[0103] (4) Blank making: When forging, the temperature of the die must not be lower than 250℃, and the 3T free forging hammer is used. Figure 5 The tooling shown is formed into the required dimensions by the process in one fire, the shaft deformation is 25%, the final forging temperature is ≥980℃, and the transfer time does not exceed 20s;

[0104] (5) Second rough turning: Press the blank after forming Figure 2 The shape is rough turned, and black skin is allowed locally on the blank;

[0105] (6) Pre-forging heating: Brush the surface of the blank with glass powder lubricant and protective agent evenly. After the glass powder protective agent is dry, the forging must be placed in the effective heating zone of the furnace for heating. The furnace temperature rises to 950℃ and then starts to load the furnace. After reaching the temperature, keep it warm for 130 minutes. After the end of the 950℃ holding period, heat it up to 1085℃ and keep it warm for 150 minutes.

[0106] (7) Pre-forging: used on 4000t electric screw press Figure 4 The die shown in the figure is pre-forged. When starting forging, the die temperature must not be lower than 250°C, the transfer time must be ≤20s, the final forging temperature must be ≥980°C, the disk deformation must be 47%, and the die cavity must be kept warm after pre-forging.

[0107] (8) Final forging heating: Forgings must be placed in the effective heating zone of the furnace. Heat the furnace temperature to 1100℃ and keep it at 1100℃ for 50 minutes;

[0108] (9) Final forging: Use a special die on an electric screw press for final forging. The die temperature must not be lower than 250°C when forging, the transfer time must be ≤20s, the final forging temperature must be ≥980°C, and the disc deformation must be 62%;

[0109] (10) The third rough turning: Press the forging after final forging Figure 4 The shape is machined, and the blank is allowed to have black skin locally;

[0110] (11) Heat treatment: Solution treatment stage: put into furnace at 650℃, heat up to 800℃ and keep warm for 2 hours, heat up to 950℃ and keep warm for 2 hours, heat up to 1080℃ and keep warm for 5 hours, then air cool and oil cool. Aging treatment stage: put into furnace at 650℃, heat up to 760℃ and keep warm for 16 hours, then air cool.

[0111] (12) Inspection: According to the requirements of the final inspection process, the dimensions of the forged turbine rotor forgings shall be inspected. The dimensions of the rotor forgings shall meet the process requirements, the forgings shall be complete in appearance, and there shall be no defects such as cracks, folds, or crushing on the surface. The mechanical properties requirements are shown in Table 3:

[0112] Table 3 Physical and chemical test results of turbine rotor forgings of Example 2

[0113]

[0114] The turbine rotor forgings produced using this method can be successfully applied to a certain type of aerospace liquid engine. This invention provides a basis for future forging die design, forging process development, and production experience for GH4586 material, filling a technological gap. Furthermore, the successful application of this method in mass production can effectively reduce costs.

[0115] The present invention has been described in detail above with reference to specific embodiments and exemplary examples. However, these descriptions should not be construed as limiting the present invention. Those skilled in the art will appreciate that various equivalent substitutions, modifications, or improvements may be made to the technical solutions and implementations of the present invention without departing from the spirit and scope of the present invention, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be determined by the appended claims.

[0116] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A forging process for a high-temperature alloy disc-shaft integrated turbine rotor die forging, characterized in that: include: S1 Determine the size of the bar material according to the size requirements of the required disc-shaft integrated turbine rotor die forgings; S2 performs the first rough turning on the bar to obtain the rough turned blank; S3: After preheating the rough-turned blank, apply glass powder lubricant and protective agent on the surface of the blank. After the glass powder lubricant and protective agent is dried, the blank is loaded into the furnace for heating. After the blank is taken out of the furnace, it is wrapped with insulation cotton and returned to the furnace for heating. S4: The heated blank with the insulation cotton is forged by a double-die tumbling and fire forming method; S5 performs a second rough turning on the forged billet; S6: Brush glass powder lubricating protective agent on the surface of the blank after the second rough turning. After the glass powder lubricating protective agent is dried, the blank is loaded into the furnace and pre-forged and heated. S7 pre-forging the pre-heated billet; S8: The pre-forged billet is loaded into the furnace for final forging heating; S9 performs final forging on the billet after final forging heating to obtain a forging; S10 performs the third rough turning on the forging; S11 performs a solution-aging heat treatment on the forging after the third rough turning to obtain a disk-shaft integrated turbine rotor die forging; In step S2, the blank obtained after the first rough turning is in a shape of thin ends and thick middle, the middle and both ends are cylindrical, the edges and joints of the middle and both ends are rounded, and the middle and both ends are respectively a disk portion and a shaft portion; In step S5, the second rough turning method is to rough turn the shaft portion of the blank according to a taper of 7 to 10 degrees, and make a smooth transition between the shaft portion and the disk portion of the blank; In steps S7 and S9, the disk portion of the blank is pre-forged and final forged; In step S10, the third rough turning of the forging is performed to remove the machining allowance in the forging, remove 1 to 2 mm of surface cold die structure, and form a fillet at the connection between the disk and the shaft of the forging. The disk and shaft of the resulting forging correspond to the disk and shaft of a turbine rotor die forging of a disk-shaft integrated type, respectively. In step S3, the rough-turned blank is preheated at 50-150°C for 10-30 minutes, a glass powder lubricant and protective agent is applied to the surface of the blank, and after the glass powder lubricant and protective agent is dried, the furnace temperature is raised to 950-980°C, the blank is loaded into the furnace, and kept at 950-980°C for 120±10 minutes. After the holding period, the temperature is raised to 1080-1100°C with the furnace. After reaching the temperature, the blank is taken out of the furnace and the entire blank is wrapped with insulation cotton. After the wrapping is completed, the blank wrapped with insulation cotton is returned to the furnace and heated to 1080-1100°C and kept at this temperature for not less than 90 minutes and not more than 140 minutes. In step S4, the temperature of the die is not less than 250±50°C when forging starts, the temperature of the die is ≥980°C when forging ends, and the deformation of the shaft portion of the blank is 20-40%; After the blank is returned to the furnace for reheating in step S3, the time from the blank being taken out of the furnace to the blank being transferred into the mold shall not exceed 30 seconds; The final forging in step S9 and the pre-forging in step S7 use the same forging die, the forging die including an upper die and a lower die, which are combined to form a die cavity, the die cavity including a shaft cavity and a disc cavity, the disc cavity having the same shape as the wheel disc of the final hot forging after adding machining allowance, and the shaft cavity having the same shape as the shaft portion of the blank obtained by the second rough turning; The circumferential surface of the disc cavity is provided with an outward closed conical flash cavity, and the disc cavity forms a symmetrical depression inward at a distance R / 2 from the center of the disc cavity, with a single side depression of 2 to 3 mm, where R is the radius of the disc cavity.

2. The forging process of a high-temperature alloy disc-shaft integrated turbine rotor die forging according to claim 1, characterized in that: In step S6, the method for pre-forging and heating the billet is to raise the furnace temperature to 950-980°C, load the billet into the furnace, and keep it at 950-980°C for 120±10 minutes. After the insulation is completed, the temperature is raised to 1085±10-1100±10°C with the furnace and kept at this temperature for not less than 100 minutes and not more than 200 minutes. In step S7, the blank is pre-forged using a forging die on an electric screw press. The temperature of the forging die is not less than 250±50°C when forging starts and is ≥980°C when forging ends. The deformation of the blank disc is between 20% and 60%. After the pre-forging heating of the billet is completed in step S6, the time from the billet being taken out of the furnace to the billet being transferred to the forging die does not exceed 30 seconds.

3. The forging process of a high-temperature alloy disc-shaft integrated turbine rotor die forging according to claim 2, characterized in that: In step S8, the method of final forging heating is to raise the temperature of the billet to 1100±10-1110±10°C along with the furnace temperature and keep the temperature for a time greater than or equal to 40 minutes and less than or equal to 200 minutes; In step S9, when the final forging is performed on the heated billet, the temperature of the forging die is not less than 250±50°C at the start of forging, and the temperature of the forging die is ≥980°C at the end of forging, and the deformation of the billet disc is between 25% and 70% during final forging; After the final forging heating of the billet is completed in step S8, the time from the billet being taken out of the furnace to the billet being transferred to the forging die does not exceed 30 seconds.

4. The forging process of a high-temperature alloy disc-shaft integrated turbine rotor die forging according to claim 1, characterized in that: The glass powder lubricating and protective agent is FR35 glass powder lubricating and protective agent; The thickness of the insulation cotton is 5 to 15 mm; The aspect ratio of the bar is 2 to 3:

1.

5. The forging process of a high-temperature alloy disc-shaft integrated turbine rotor die forging according to claim 1, characterized in that: In step S7, the under-pressure ring is used to control the pre-forging deformation during pre-forging, and in step S9, the under-pressure ring is removed during final forging.

6. The forging process for a high-temperature alloy disc-shaft integrated turbine rotor die forging according to claim 1, characterized in that: In step S11, the method for performing solution-aging heat treatment is: Solution treatment stage: put the forging into the furnace at 650±10℃, heat it up to 800±10℃ and keep it for 2~3 hours, heat it up to 950±10℃ and keep it for 2~3 hours, heat it up to 1080±10℃ and keep it for 5~6 hours, then cool it in air and oil at room temperature after taking it out of the furnace; Aging treatment stage: Place the forgings into the furnace at 650±10℃, heat up to 760±10℃ and keep warm for 16 to 20 hours, then air cool after taking them out of the furnace.

7. The forging process for a high-temperature alloy disc-shaft integrated turbine rotor die forging according to claim 1, characterized in that: It also includes testing the surface quality, metallographic structure and mechanical properties of disc-shaft integrated turbine rotor die forgings, and forgings that meet the testing standards are considered qualified forgings; The standards for surface quality inspection include: no defects on the surface of forgings, including cracks, folds, delaminations, inclusions or voids; The standards for metallographic structure testing include: grain purity is assessed according to the Class B rating chart specified in GB / T14999.5; low-magnification structure inspection shows no visible defects, including cracks, pinholes, slag inclusions, or porosity; The standards for mechanical properties testing are as follows: Among them, Rm, Rp0.2, A, Z, impact ak, σ, and τ are tensile strength, yield strength, elongation, cross-sectional shrinkage, impact toughness, endurance stress, and endurance time, respectively.

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