Special-shaped rolling method for high-temperature alloy high-pressure compressor casing forged piece

Abstract

The invention discloses a high-temperature alloy high-pressure compressor casing forge piece special-shaped rolling method which comprises the following steps: S1, carrying out pretreatment on an original high-temperature alloy blank, including blanking and chamfering; s2, the blank obtained after broaching is subjected to two times of pre-rolling, and the pre-rolling deformation is controlled to range from 13% to 18%; s3, the pre-rolled ring blank is put into a tire mold cavity for staged forging forming; and S4, carrying out heat treatment on the forge piece subjected to loose tooling forging forming to obtain a target forge piece. According to the method, the problem of local filling defects can be solved without shaping after forming die forging and without increasing the outer diameter allowance.

Description

Technical Field

[0001] This invention belongs to the field of metal forming technology, and specifically relates to a method for irregular rolling of high-temperature alloy high-pressure compressor casing forgings. Background Technology

[0002] In the field of aero-engines, the precise forming of high-performance, irregularly shaped ring forgings for engine casings is one of the key technological challenges. These forgings are typically manufactured from difficult-to-deform materials such as high-temperature alloys, resulting in complex structures and extremely high requirements for dimensional accuracy and performance. Current mainstream forming process chains, encompassing forging billet preparation, preform design, and final forming, still face significant challenges in handling complex, irregularly shaped structures.

[0003] One prominent technical bottleneck is that the high-temperature alloy rear support casing forging is prone to local insufficiency during the forming process. To solve this problem, the industry generally adopts two methods: (1) increasing the local blank allowance of the outer diameter: attempting to compensate for insufficient filling by reserving more material; (2) adding a shaping process after die forging: performing additional correction processing after the initial forming.

[0004] However, these existing solutions have significant shortcomings: Method (1) leads to a significant increase in raw material consumption, a huge amount of subsequent machining, and low overall production efficiency and material utilization; Method (2) complicates the process flow, increases the uncertainty and control difficulty of the production process, and significantly increases energy consumption. Therefore, the industry urgently needs to develop a high-efficiency, low-consumption precision forming process for irregularly shaped ring forgings to solve the problem of local filling defects, while breaking through the excessive dependence of existing technologies on resources and energy consumption. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a method for irregularly shaped rolling of high-temperature alloy high-pressure compressor casing forgings, which eliminates the need for shaping after die forging and for increasing the outer diameter allowance, thereby resolving the problem of localized filling defects.

[0006] The main technical solution adopted in this invention is as follows:

[0007] A method for irregularly shaped rolling of a high-temperature alloy high-pressure compressor casing forging includes the following steps:

[0008] S1: Pretreatment of the original high-temperature alloy billet;

[0009] S2: The expanded blank is pre-rolled twice, and the pre-rolling deformation is controlled at 13%-18%;

[0010] S3: The pre-rolled ring billet is placed into the die cavity for staged forging and forming;

[0011] S4: Heat treatment is performed on the forging after it has been formed by die forging to obtain the target forging.

[0012] Preferably, the specific preprocessing method of S1 is as follows:

[0013] S1-1: Heat the billet to the preset temperature T0, hold for 60min-150min, and perform upsetting, spinning and punching according to the preset dimensions;

[0014] S1-2: Reheat the billet to T0 in the furnace, hold for 30 minutes, and then roll it into a round shape, controlling the final forging temperature to be ≥900℃;

[0015] S1-3: Heat the billet to the preset temperature T0, hold for 40min-130min, then expand the hole to the preset size, and control the final forging temperature ≥900℃.

[0016] Preferably, in step S2, the specific steps for the two pre-rolled rings are as follows:

[0017] S2-1: Heat the billet to the preset temperature T0, hold for 30-120 minutes, and perform a ring rolling according to the preset dimensions;

[0018] S2-2: The billet is reheated to T0℃ in the furnace, held for 30 minutes, and then rolled into a ring for the second time. The final forging temperature is controlled to be ≥900℃.

[0019] Preferably, in step S3, the specific steps of mold forging are as follows:

[0020] S3-1: Heat the billet to the preset temperature T0, hold for 30-120 minutes, and perform a single spinning forging according to the preset dimensions;

[0021] S3-2: The billet is reheated to T0℃ in the furnace, held for 30 minutes, and then placed into the die cavity for staged forging. The final forging temperature is controlled to be ≥900℃. The staged forging includes:

[0022] Phase 1: Forging time is 0-10 seconds, and forging pressure is controlled at 12%-20% P. max Under low pressure, the preformed blank is initially fitted with the mold cavity;

[0023] Phase 2: Forging time is 10-20 seconds, and forging pressure is controlled at 47%-58% P. max Complete 60% cavity filling;

[0024] Phase 3: Forging time is 20-50 seconds, and forging pressure is controlled at 70%-100% P. max ;

[0025] Phase 4: Forging time is 50-70 seconds, and forging pressure is controlled at 43%-63% P. max ;

[0026] Phase 5: Forging time is 70-80 seconds, and forging pressure is controlled at 16%-28% P. max ;

[0027] P max Maximum forging pressure, and P max =k×σ×A;

[0028] Where σ is the flow stress of the high-temperature alloy at the forging temperature; A is the projected contact area between the forging and the die; and K is the process coefficient, which ranges from 1.5 to 2.0.

[0029] Preferably, in step S4, the specific method of heat treatment is as follows: the billet is loaded into the furnace at ≤750°C, heated to 900±10°C, held for 60 minutes, and then air-cooled.

[0030] Preferably, the tooling is preheated to 250-350°C before all forging processes, and the billet transfer time is ≤60 seconds.

[0031] Preferably, the billet is air-cooled after all forging processes.

[0032] Beneficial effects: This invention provides a method for irregularly shaped rolling of high-temperature alloy high-pressure compressor casing forgings, which has the following advantages:

[0033] (1) This invention uses a composite process of "spinning preforming + die forging" to precisely control the flow of metal, avoid the problem of insufficient local filling, eliminate the need for additional outer diameter allowance or subsequent shaping process, reduce material waste and processing volume, improve the consistency and density of finished products, and reduce rework caused by poor forming effect in forging, thereby improving overall efficiency and reducing energy consumption.

[0034] (2) By controlling the pressure in stages, optimizing the process flow, reducing energy consumption and costs, shortening the operation time of the high-pressure section, and avoiding the energy consumption and process complexity caused by multiple heating and shaping in the traditional process, the overall production efficiency is higher. Attached Figure Description

[0035] Figure 1 The heating curve in step 1-1 of Example 1;

[0036] Figure 2 The heating curves for steps 1-3 in Example 1;

[0037] Figure 3 The heating curve in step 2-1 of Example 1;

[0038] Figure 4 The heating curve in step 3-1 of Example 1;

[0039] Figure 5The heat treatment temperature curve in step 4 of Example 1;

[0040] Figure 6 The die forging dimensions are those for step 3 in Example 1;

[0041] Figure 7 The image shows the billet after optimization simulation in Example 1 (before die forging);

[0042] Figure 8 The image shown is a forging diagram after optimization simulation in Example 1 (after die forging). Detailed Implementation

[0043] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application are clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0044] Example 1

[0045] This embodiment uses high-temperature alloy GH4169 as raw material and employs a special-shaped rolling method to form the high-pressure compressor casing. The specific steps are as follows:

[0046] Step 1: Cut, chamfer, and pre-treat the original high-temperature alloy billet;

[0047] In this invention, the preset temperature is determined based on the material properties of the high-temperature alloy. At this temperature, the plasticity, microstructure control, and deformation resistance of the material can achieve a better balance. Those skilled in the art can adapt the preset temperature T0 according to actual process requirements. In this embodiment 1, the high-temperature alloy used is GH4169, with a corresponding T0 value of 1010℃ and a corresponding T0 value of 1010±1℃. In this embodiment 1, the holding coefficient for cold material during heating is calculated as 0.6 min / mm, and for hot material as 0.3 min / mm.

[0048] In Example 1, the original high-temperature alloy billet has a blanking size of Φ200(+3 / -2)×290(+5 / 0) mm and a blanking weight of 79(+3 / 0) kg; the chamfer is R10, in mm. The specific pretreatment method is as follows:

[0049] Step 1-1: After the billet is loaded into the furnace, according to... Figure 1The heating curve shown heats the billet to a preset temperature of 1010±10℃ and holds it for 60min-150min. Then, a 3150T high-speed forging machine is used to upset and punch the billet. During the upset process, the billet is spun to a smaller end to ~H=186±3mm and punched with a diameter of Φ120mm.

[0050] Steps 1-2: Reheat the billet to T0 (1010±10℃) in the furnace, hold for 30 minutes, roll it into a round shape, remove the chamfer to Φ285±5×Φ140±5×186±3mm, air cool, and allow the hot material to be returned to the furnace without damage, ensuring the transfer time is ≤60S; among which, ensure the final forging temperature is ≥900℃, preheat the tooling to 250-350℃ before forging, and the hammer head pressing speed is 20~70mm / s during the forging stage.

[0051] Steps 1-3: After the billet is loaded into the furnace, according to... Figure 2 The heating curve shown heats the billet to a preset temperature of 1010±10℃ and holds it for 40-130 minutes. Then, a 3150T high-speed forging machine and a 0.6m ring mill are used to expand the billet to the preset size and flatten it to a height of Φ310±5×Φ180±5×180±3. The billet is then air-cooled and allowed to be returned to the furnace without damage. The final forging temperature is guaranteed to be ≥900℃. The tooling is preheated to 250-350℃ before forging.

[0052] Step 2: Roll the billet into rings using a 0.6m ring mill; the specific steps are as follows:

[0053] Step 2-1: After the billet is loaded into the furnace, according to... Figure 3 The heating curve shown heats the billet to a preset temperature of 1010±10℃ and holds it for 30-120 minutes. Then, it is rolled into a ring according to the preset size, with the end face flattened to Φ345±5×Φ230±5×174±5, in mm.

[0054] Step 2-2: Reheat the billet to 1010℃ in the furnace, hold for 30 minutes, and then perform a second ring rolling to flatten the end face to Φ394±3×Φ295±3×168±5 (unit: mm). Air cool. If there is no damage, hot material can be returned to the furnace. Ensure the final forging temperature is ≥900℃, control the pre-rolling deformation to 13%-18%, and preheat the tooling to 250-350℃ before forging.

[0055] Step 3: Use a 3150T high-speed forging mill to forge the billet after ring rolling using a die; the specific steps are as follows:

[0056] Step 3-1: After the billet is loaded into the furnace, according to... Figure 4 The heating curve shown heats the billet to a preset temperature of 1010±10℃ and holds it for 30min-120min. The heated billet is then spun and forged once according to the preset dimensions, with the spun dimensions reaching H=160±5mm.

[0057] Step 3-2: The billet is reheated to 1010℃ in the furnace and held for 30 minutes. Then, it is placed into the die cavity for staged forging. The formed forging is air-cooled, and the final forging temperature is controlled to be ≥900℃. The transfer time is ensured to be ≤60 seconds. The tooling is preheated to 250-350℃ before forging. The specific stages of staged die forging are as follows:

[0058] Phase 1: Forging time is 0-10 seconds, and forging pressure is controlled at 12%-20% P. max (≈450-745T), under low pressure, the preformed blank is initially fitted with the mold cavity to eliminate the initial gap. Under low pressure, the preformed blank is initially fitted with the mold cavity to avoid blank displacement or local stress concentration caused by sudden high pressure.

[0059] Phase 2: Forging time is 10-20 seconds, and forging pressure is controlled at 47%-58% P. max (≈1200-1470T), completing 60% cavity filling;

[0060] Phase 3: Forging time is 20-50 seconds, and forging pressure is controlled at 70%-100% P. max (≈1800-2550T), breaking through the peak value of alloy flow stress, and using pressure to fill the difficult-to-form area with metal, ensuring that the cavity is filled;

[0061] Phase 4: Forging time is 50-70 seconds, and forging pressure is controlled at 43%-63% P. max (≈1100-1600T), achieving dimensional accuracy control;

[0062] Phase 5: Forging time is 70-80 seconds, and forging pressure is controlled at 16%-28% P. max (≈400-720T), releasing residual stress and reducing pressure makes it easier for the forging to be demolded from the mold.

[0063] P max For maximum forging pressure, and P max =k×σ×A;

[0064] Where σ is the flow stress of the high-temperature alloy at the forging temperature; A is the projected contact area between the forging and the die; K is the process coefficient, with a value of 1.5-2.0. In this Example 1, P max It is 2550T.

[0065] Step 4: Perform solution heat treatment on the forgings after die forging. The heat treatment temperature curve is as follows: Figure 5 As shown. The billet is loaded into the furnace at ≤750℃, heated to 980±10℃, held for 60 minutes, and then air-cooled.

[0066] In step 3 (die forging process) of this embodiment, the punch is pressed in to a position flush with the end face of the billet. For specific dimensions, please refer to [reference needed]. Figure 6 . Figure 7 The simulation results for the blank before forging were shown below. The simulation parameters were set to shear stress and friction coefficient μ = 0.4, reflecting the interaction between the die, punch, and blank. The simulation results after forging are as follows: Figure 8 As shown. Comparison Figure 7 and Figure 8 It can be seen that when the "spinning preforming + die forging" composite process (step 3) is adopted, the spinning preforming in step 3-1 lays a good material foundation for the subsequent die forging, effectively ensuring the integrity of the mold cavity filling.

[0067] The reason for introducing the spinning preforming process is that when the shape of the blank after ring rolling differs significantly from the final shaped part, direct die forging can easily lead to a large amount of material extrusion, resulting in insufficient forming and material waste. Therefore, in step 3-1 of this embodiment, by spinning the blank to a preset size, the material is initially distributed under controllable unidirectional pressure, and local thick-walled areas are pre-accumulated, so that the metal fills the die cavity more evenly during die forging, reducing internal defects and improving the density of the microstructure. The optimized blank morphology is as follows: Figure 7 As shown. Subsequently, in the staged die forging design of step 3-2, by precisely controlling the metal flow and optimizing the stress state of the die, the forming quality is improved while also considering production efficiency and cost control. Combining spin preforming with staged die forging can significantly shorten the high-pressure action time and avoid typical defects such as "uneven flow lines" and "folding". Figure 8 As shown, the final forging achieved good forming results.

[0068] Hardness tests were performed on three evenly distributed test points on one end face of the forging prepared in Example 1. The measured values ​​were HB = 265, 272, and 268, respectively. Furthermore, the grain size of the forging was determined to be 5.5-6.0 grade, meeting the aerospace standard requirements (≥4 grade).

[0069] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for irregularly shaped rolling of a high-temperature alloy high-pressure compressor casing forging, characterized in that, Includes the following steps: S1: Pretreatment of the original high-temperature alloy billet; S2: The expanded billet is pre-rolled twice, and the pre-rolling deformation is controlled at 13%-18%; S3: The pre-rolled ring billet is placed into the die cavity for staged forging and forming; S4: Heat treatment is performed on the forging after it has been formed by die forging to obtain the target forging.

2. The method for irregular rolling of high-temperature alloy high-pressure compressor casing forgings according to claim 1, characterized in that, The specific preprocessing method for S1 is as follows: S1-1: Heat the billet to the preset temperature T0, hold for 60min-150min, and perform upsetting, spinning and punching according to the preset dimensions; S1-2: Reheat the billet to T0 in the furnace, hold for 30 minutes, and then roll it into a round shape, controlling the final forging temperature to be ≥900℃; S1-3: Heat the billet to the preset temperature T0, hold for 40min-130min, then expand the hole to the preset size, and control the final forging temperature ≥900℃.

3. The method for irregular rolling of high-temperature alloy high-pressure compressor casing forgings according to claim 1, characterized in that, In step S2, the specific steps for the two pre-rolled rings are as follows: S2-1: Heat the billet to the preset temperature T0, hold for 30-120 minutes, and perform a ring rolling according to the preset dimensions; S2-2: The billet is reheated to T0℃ in the furnace, held for 30 minutes, and then rolled into a ring for the second time. The final forging temperature is controlled to be ≥900℃.

4. The method for irregular rolling of high-temperature alloy high-pressure compressor casing forgings according to claim 1, characterized in that, In step S3, the specific steps of mold forging are as follows: S3-1: Heat the billet to the preset temperature T0, hold for 30-120 minutes, and perform a single spinning forging according to the preset dimensions; S3-2: The billet is reheated to T0℃ in the furnace, held for 30 minutes, and then placed into the die cavity for staged forging. The final forging temperature is controlled to be ≥900℃. The staged forging includes: Phase 1: Forging time is 0-10 seconds, and forging pressure is controlled at 12%-20% P. max Under low pressure, the preformed blank is initially fitted with the mold cavity; Phase 2: Forging time is 10-20 seconds, and forging pressure is controlled at 47%-58% P. max Complete 60% cavity filling; Phase 3: Forging time is 20-50 seconds, and forging pressure is controlled at 70%-100% P. max ; Phase 4: Forging time is 50-70 seconds, and forging pressure is controlled at 43%-63% P. max ; Phase 5: Forging time is 70-80 seconds, and forging pressure is controlled at 16%-28% P. max ; P max Maximum forging pressure, and P max =k×σ×A; Where σ is the flow stress of the high-temperature alloy at the forging temperature; A is the projected contact area between the forging and the die; and K is the process coefficient, which ranges from 1.5 to 2.

0.

5. The method for irregular rolling of high-temperature alloy high-pressure compressor casing forgings according to claim 1, characterized in that, In S4, the specific heat treatment method is as follows: the billet is loaded into the furnace at ≤750℃, heated to 900±10℃, held for 60 minutes, and then air-cooled.

6. The method for irregular rolling of high-temperature alloy high-pressure compressor casing forgings according to claim 1, characterized in that, Preheat the tooling to 250-350℃ before all forging processes, and the billet transfer time should be ≤60 seconds.

7. The method for irregular rolling of high-temperature alloy high-pressure compressor casing forgings according to claim 1, characterized in that, After all forging processes, the billet is air-cooled.

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