Precise forging method and forging die for adaptive shaft of large-scale high-temperature alloy rotor

Abstract

The invention discloses a large-scale high-temperature alloy rotor adaptive shaft precision forging method and a forging die, and belongs to the technical field of high-end equipment manufacturing. Heating the blank to a forging temperature; the blank is placed in a cavity of the lower mold, and then the upper mold and the lower mold are controlled to be closed; controlling the left and right horizontal punches to move respectively to form an inner hole cavity of the blank; the left horizontal punch and the right horizontal punch are controlled to return to the initial positions; the left horizontal die and the right horizontal die are controlled to move respectively, and upsetting of the prefabricated blank is completed; an inner hole cavity of the forge piece is shaped; and finally, a required rotor adaptive shaft is obtained. The forging die comprises an upper die, a lower die, a left horizontal die, a right horizontal die, a left horizontal punch and a right horizontal punch. The method can meet the urgent requirements of advanced heavy duty gas turbines on the aspects of product quality, manufacturing cost and the like, and has great economic and social benefits.

Description

Technical Field

[0001] The present invention belongs to the field of high-end equipment manufacturing, and in particular to the field of forging technology, and specifically to a precision forging method and a forging die for a large high-temperature alloy rotor adapter shaft. Background Art

[0002] The rotor adapter shaft is one of the most important load-bearing components in heavy-duty gas turbines. Its shape is an axisymmetric rotating body, including a cylindrical body with a through hole, and a flange at each end of the cylindrical body. It is mainly used to connect the rotating shaft and needs to withstand high temperature, high pressure and transmission torque for a long time. The service conditions are extremely harsh, which places high requirements on the high-temperature tensile, high-temperature durability, high-temperature creep and high-cycle fatigue performance of the rotor adapter shaft. Therefore, in addition to the use of expensive high-temperature alloy materials, the rotor adapter shaft parts also have high requirements on their manufacturing process.

[0003] The rotor adapter shaft forgings for heavy-duty fuel turbines generally weigh more than 1 ton. They use traditional ordinary die forging technology. Due to the need for demolding, it is necessary to design and add a process block between the two flanges, which results in a great waste of expensive metal materials and high production costs. In addition, the streamlines of the cylindrical body of the rotor adapter shaft die forging are cut off and exposed, affecting the comprehensive mechanical properties of the parts such as service fatigue.

[0004] Multi-directional die forging technology is currently an important means of manufacturing hollow special-shaped parts. However, there are great challenges in using multi-directional die forging for large high-temperature alloy rotor adapter shaft forgings: high-temperature alloy materials have great deformation resistance. Using conventional multi-directional die forging technology, the horizontal forging load will exceed 20,000 tons, and the existing equipment capacity cannot provide such a high forging capacity; the deformation process window of high-temperature alloy materials is narrow. If the forging deformation is less than 30% in any fire, the risk of unqualified organizational properties of the forging will increase sharply, resulting in scrapping. Therefore, it is impossible to achieve rotor adapter shaft forging through multi-fire multi-directional die forging.

[0005] Therefore, how to reduce the forging forming load to achieve precision forging of the high-temperature alloy rotor adapter shaft has become a technical problem that technicians in this field continue to solve. Summary of the invention

[0006] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to solve the problems of large material consumption and incomplete streamlines in the traditional production process, and to provide a precision forging method and forging die for a large high-temperature alloy rotor adapter shaft, which can meet the urgent needs of advanced heavy-duty gas turbines in terms of product quality and manufacturing cost, and has great economic and social benefits.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: a method for precision forging of a large high-temperature alloy rotor adapter shaft, characterized in that it includes the following steps: Step 1: Process the cylindrical blank according to the outer dimensions of the forging; Step 2: Heat the blank to the forging temperature, then take out the blank, cover the surface of the blank with glass powder binder, and then cover it with insulation cotton, and heat and keep the blank warm again for a certain period of time; Step 3: Place the heated blank in the cavity of the lower mold, and then control the upper mold to move downward, and continue to move downward after contacting the blank until the upper mold and the lower mold are closed, completing the pressing action; Step 4: The upper die is kept in a downward pressing state, and then the left horizontal punch is controlled to move to the right to contact the blank, and at the same time, the right horizontal punch is controlled to move to the left to contact the blank; the left and right horizontal punches are continued to be controlled to move to the specified target positions respectively to form the inner cavity of the blank; Step 5: Control the left and right horizontal punches to perform return motion respectively until they return to their initial positions, thereby completing the preparation of the preform with the inner cavity; Step 6: Control the left horizontal die to move rightward until it contacts the preform, and at the same time, control the right horizontal die to move leftward until it contacts the preform, and then simultaneously control the left horizontal die and the right horizontal die to move to the designated target positions respectively, to complete the upsetting of the preform; Step 7: Control the left horizontal die and the right horizontal die to make a return motion respectively, and stop after reaching the specified position, and then control the left horizontal punch to move to the right again and enter the inner hole cavity of the billet. At the same time, control the right horizontal punch to move to the left and enter the inner hole cavity of the billet, until the left and right horizontal punches move to the specified target positions respectively, and complete the shaping of the inner hole cavity of the forging; Step 8: Finally, control the left horizontal punch, the right horizontal punch, the left horizontal die, the right horizontal die and the upper die to return to the initial positions to obtain the required rotor adapter shaft.

[0008] Furthermore, the diameter of the cylindrical blank is 0.1-5 mm smaller than the maximum diameter of the inner hole formed after the upper mold and the lower mold are molded together.

[0009] Furthermore, the thickness of the thermal insulation cotton covering the surface of the cylindrical blank is 5 to 10 mm.

[0010] Furthermore, in step 4, after the left and right horizontal punches move to the specified target position, the spacing between the left and right horizontal punches is 40-60 mm, so that the thickness of the skin between the left inner cavity and the right inner cavity of the blank is 40-60 mm.

[0011] Furthermore, in step 4, the forging load of the billet is 2900 tons.

[0012] Furthermore, in step six, the forging load of upsetting is 5000 tons.

[0013] Furthermore, in step seven, the forging load for shaping the inner cavity is 800 tons. A precision forging die for a large high-temperature alloy rotor adapter shaft, characterized in that it includes an upper die, a lower die, a left horizontal die, a right horizontal die, a left horizontal punch and a right horizontal punch; the shape of the inner hole formed after the upper die and the lower die are combined matches the side shape of the rotor adapter shaft to be processed; the left horizontal die and the right horizontal die are respectively arranged at the two ends of the lower die, and their axis lines coincide with the axis line of the inner hole formed after the upper die and the lower die are combined, and can slide in the inner hole formed after the upper die and the lower die are combined; through holes are opened on the left horizontal die and the right horizontal die respectively along their axis lines, and the stamping ends of the left horizontal punch and the right horizontal punch respectively pass through the left horizontal die and the right horizontal die and extend into the lower die, and are respectively connected to the left horizontal die and the right horizontal die in a sliding manner.

[0014] Furthermore, the end faces of the left horizontal mold and the right horizontal mold extending into the lower mold are both stepped surfaces, wherein the inner ring surface close to the inner side of the end faces of the left horizontal mold and the right horizontal mold protrudes from the outer ring surface close to the outer side, and the thickness of the protruding part is 10~20mm, the area of ​​the inner ring surface is 0.8~1.2 times the area of ​​the outer ring surface, and the connection between the inner ring surface and the outer ring surface is chamfered.

[0015] Compared with the prior art, the present invention has the following advantages: 1) By adopting the method of multiple partitioned local loading, the traditional large contact area extrusion deformation in the horizontal direction of multi-directional die forging is transformed into extrusion punching + ring upsetting + punching shaping with a small contact area, which can greatly reduce the forming load of large high-temperature alloy rotor adapter shaft forgings during multi-directional die forging by more than 60%.

[0016] 2) The present invention adopts one-fire precision forging to avoid the problem of streamline being cut off at the cylindrical body of the rotor adapter shaft die forging. The maximum forming load is only 6,000 tons, the forging times are reduced by 75%, the forming load is reduced by 87.5%, the material consumption can be reduced by more than 30%, and the machining time can be reduced by more than 20%. The material cost alone can save 141,000 yuan per piece, which has significant economic benefits.

[0017] 3) It can realize the complete forming of the overall characteristic structure of the rotor adapter shaft, without adding auxiliary features such as process blocks and flash, realizing the full streamline forging of metal, improving the comprehensive mechanical properties of the product, ensuring product quality, and high production efficiency, which is helpful for the service requirements of advanced heavy equipment for the safety and reliability of key components. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A forging flow chart for machining a rotor adapter shaft forging according to the present invention.

[0019] Figure 2 It is a schematic diagram of the structure of the forging die in the present invention.

[0020] Figure 3 It is a schematic diagram of the structure of a rotor adapter shaft forging for a heavy-duty gas turbine in an embodiment of the present invention.

[0021] In the figure: 1—cylindrical blank, 2—lower die, 3—upper die, 4—left horizontal punch, 5—right horizontal punch, 6—left horizontal die, 7—right horizontal die. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0023] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In the description of the present invention, it should be noted that the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the invention product is usually placed when used, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In addition, the terms "horizontal", "vertical", etc. do not mean that the components are absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] Example: See Figure 1 A method for precision forging a large high-temperature alloy rotor adapter shaft comprises the following steps: Step 1: Process the cylindrical blank 1 according to the outer dimensions of the forging (rotor adapter shaft to be processed); at the same time, select or process the corresponding combined die according to the size of the forging.

[0026] Step 2: Heat the blank to the forging temperature, then take out the blank, cover the surface of the blank with glass powder binder, and then cover it with insulation cotton, and heat and keep the blank again for a certain period of time; wherein, the thickness of the insulation cotton covering the surface of the cylindrical blank 1 is 5~10mm; thereby improving the insulation effect.

[0027] Step 3: Place the heated blank in the cavity of the lower mold 2, and then control the upper mold 3 to move downward, and continue to move downward after contacting the blank until the upper mold and the lower mold are closed, and the pressing action is completed. Among them, the diameter of the cylindrical blank 1 is smaller than the maximum diameter of the inner hole formed after the upper mold 3 and the lower mold 2 are closed, which is 0.1-5mm; in this way, the diameter of the cylindrical blank 1 is slightly smaller than the diameter of the cylindrical body of the sleeve forging. When the upper mold and the lower mold are closed to extrude the cylindrical blank 1, no flash will be formed at the die mouth of the combined mold; thereby effectively reducing the processing steps, ensuring the processing quality, and improving the processing efficiency.

[0028] Step 4: The upper die 3 is kept in the downward pressure state, and then the left horizontal punch 4 and the right horizontal punch 5 are added to the action, and the left horizontal punch 4 is controlled to move to the right to contact the blank, and at the same time, the right horizontal punch 5 is controlled to move to the left to contact the blank; continue to control the left and right horizontal punches 5 to move to the specified target position respectively, and form the inner hole cavity of the blank. That is, a cylindrical groove is formed at both ends of the cylindrical blank 1, and the interval between the two cylindrical grooves forms a skin; by controlling the stroke of the horizontal punch, the thickness of the formed skin can be accurately controlled to avoid secondary processing, thereby helping to improve the processing accuracy and efficiency of the entire forging. Among them, the forging load of the blank is 2900 tons. As an embodiment, after the left and right horizontal punches 5 move to the specified target position, the spacing between the left and right horizontal punches 5 is 40-60mm, so that the skin thickness between the inner hole cavity on the left side of the blank and the inner hole cavity on the right side is 40~60mm.

[0029] Step 5: Control the left and right horizontal punches 5 to perform return motion respectively until they return to their initial positions, thereby completing the preparation of the preform with an inner cavity.

[0030] Step 6: The left horizontal die 6 and the right horizontal die 7 join the action, control the left horizontal die 6 to move rightward until it contacts the prefabricated blank, and at the same time, control the right horizontal die 7 to move leftward until it contacts the prefabricated blank, and then simultaneously control the left horizontal die 6 and the right horizontal die 7 to move to the designated target positions respectively, completing the upsetting of the prefabricated blank. Among them, the upsetting forging load is 5000 tons.

[0031] Step 7: Control the left horizontal die 6 and the right horizontal die 7 to make a return movement respectively, until they reach the designated position and stop; then the left horizontal punch 4 and the right horizontal punch 5 join the action again, control the left horizontal punch 4 to move to the right and enter the inner hole of the blank, and at the same time, control the right horizontal punch 5 to move to the left and enter the inner hole of the blank, until the left and right horizontal punches 5 move to the designated target positions respectively, and complete the shaping of the inner hole of the forging; wherein, the forging load of the inner hole shaping is 800 tons. When shaping the inner hole, the side wall of the forging is always under the constraint of the upper and lower dies 2, so it will not deform; at the same time, the overall deformation of the inner hole shaping is very small, and the deformation is mainly concentrated in the inner hole of the forging, so the deformation of the end face of the forging can be ignored.

[0032] Step 8: Finally, control the left horizontal punch 4, the right horizontal punch 5, the left horizontal die 6, the right horizontal die 7 and the upper die 3 to return to the initial positions to obtain the required rotor adapter shaft. See also Figure 2 The present invention also discloses a precision forging die for a large high-temperature alloy rotor adapter shaft, comprising an upper die 3, a lower die 2, a left horizontal die 6, a right horizontal die 7, a left horizontal punch 4 and a right horizontal punch 5. The shape of the inner hole formed after the upper die 3 and the lower die 2 are molded together matches the side shape of the rotor adapter shaft to be processed, and the inner hole formed after the molds are molded together is a horizontal hole. The left horizontal die 6 and the right horizontal die 7 are respectively arranged at the two ends of the lower die 2, and their axis center lines coincide with the axis center lines of the inner hole formed after the upper die 3 and the lower die 2 are molded together, and can slide in the inner hole formed after the upper die 3 and the lower die 2 are molded together. On the left horizontal die 6 and the right horizontal die 7, through holes are respectively opened along their axis center lines, and the punching ends of the left horizontal punch 4 and the right horizontal punch 5 respectively pass through the left horizontal die 6 and the right horizontal die 7 and extend into the lower die 2, and are respectively connected with the left horizontal die 6 and the right horizontal die 7 in a sliding fit. Among them, the diameter of the horizontal punch is consistent with the inner hole diameter of the rotor adapter shaft forging, with a draft angle of 1~2°; the inner diameter of the horizontal die is 5~10mm larger than the diameter of the horizontal punch; the outer diameter of the horizontal die is 20~30mm smaller than the outer diameter of the rotor adapter shaft forging flange.

[0033] During implementation, the end faces of the left horizontal die 6 and the right horizontal die 7 extending into the lower die 2 are both stepped surfaces, wherein the inner ring surface close to the inner side of the end faces of the left horizontal die 6 and the right horizontal die 7 protrudes from the outer ring surface close to the outer side, and the thickness of the protruding part is 10-20 mm, the area of ​​the inner ring surface is 0.8-1.2 times the area of ​​the outer ring surface, and the connection between the inner ring surface and the outer ring surface is chamfered. In this way, by forming a drop at the forging end faces of the left horizontal die 6 and the right horizontal die 7, there is a time difference in the contact between the horizontal die and the blank during the ring upsetting deformation, the inner ring surface contacts the outer ring surface first, and as the deformation proceeds, the outer ring surface contacts the blank, which can effectively slow down the increase speed of the deformation load of the ring upsetting, and can further reduce the horizontal forging forming load. In order to improve the stability and service life of the entire forging die and reduce the cost, different materials are used for the horizontal punch and the horizontal die; preferably, the material of the horizontal punch is a high-temperature alloy material with excellent high-temperature performance, such as GH4169; the material of the horizontal die is an ordinary die steel material, such as 5CrMnMo.

[0034] During the forging process, the blank is placed horizontally in the lower die 2, and the upper die 3 driven by the hydraulic cylinder is used to apply force to the top of the blank. The left horizontal die 6, the right horizontal die 7, the left horizontal punch 4 and the right horizontal punch 5 are driven by hydraulic cylinders respectively, and the ends of the left horizontal punch 4 and the left horizontal die 6 can be respectively extended into the left opening of the die body and used to apply force to the left side of the blank, and the ends of the right horizontal punch 5 and the right horizontal die 7 can be respectively extended into the right opening of the die body and used to apply force to the right side of the blank.

[0035] This scheme adopts the method of multiple partitioned local loading to transform the traditional large contact area extrusion deformation in the horizontal direction of multi-directional die forging into small contact area extrusion punching + ring upsetting + punching shaping, which can greatly reduce the forming load of large high-temperature alloy rotor adapter shaft forgings during multi-directional die forging by more than 60%.

[0036] At the same time, the use of one-shot precision forging avoids the problem of streamline being cut off at the cylindrical body of the rotor adapter shaft die forging. The maximum forming load is only 6,000 tons, the number of forging shots is reduced by 75%, the forming load is reduced by 87.5%, the material consumption can be reduced by more than 30%, and the machining time can be reduced by more than 20%. The material cost alone can save 141,000 yuan per piece, which has significant economic benefits. In the end, the complete forming of the overall characteristic structure of the rotor adapter shaft can be achieved, without the need to add auxiliary features such as process blocks and flash, and the full streamline forging of the metal is realized, which improves the comprehensive mechanical properties of the product, ensures product quality, and has high production efficiency, which helps to meet the service requirements of advanced heavy equipment for the safety and reliability of key components. See also Figure 3The following is a detailed description of the manufacturing method of the present invention, taking a rotor adapter shaft forging for a heavy-duty gas turbine as an example. The outer contour dimensions of the forging are 646 (outer diameter) * 250 (inner diameter) * 475 (height) mm, the widths of the left and right flanges are both 116 mm, the outer diameter of the cylindrical body of the forging is 496 mm, and the weight of the forging is 905 kg. The specific manufacturing steps are as follows: Step 1: Design the die and cylindrical blank according to the forging dimensions. The horizontal punch has a diameter of 250mm and a draft angle of 1°; the horizontal die has an outer diameter of 620mm and an inner diameter of 255mm. The end in contact with the blank (forging end) is a stepped surface with a drop (height difference) of 15mm. The step transition is an R10mm rounded transition; the blank dimensions are 490mm in diameter and 610mm in length.

[0037] Step 2: Heat the blank to the forging temperature of 1010℃, then take out the blank, cover the surface with glass powder binder and then wrap it with 10mm thick insulation cotton, return the blank to the furnace and heat it for 90 minutes, and then place the heated blank in the lower mold cavity.

[0038] Step 3: The upper die moves downward and contacts the blank to complete the downward pressing action. This step is similar to the conventional forging deformation process, but the diameter of the cylindrical blank is 0~5mm smaller than the diameter of the cylindrical body of the sleeve forging. Therefore, after the upper die and the lower die are closed, no flash will be formed at the horizontal die opening.

[0039] Step 4: The upper die maintains the pressure (downward pressure state) and stops, the left horizontal punch and the right horizontal punch join the action, the left horizontal punch moves to the right and contacts the blank, at the same time, the right horizontal punch moves to the left and contacts the blank, the left horizontal punch and the right horizontal punch move 270mm to the target position respectively, and extrude and punch the blank.

[0040] Step 5: The left horizontal punch and the right horizontal punch make a return motion respectively, and stop after reaching the specified position. At this time, the prefabricated part with a skin thickness of 60 mm is completed.

[0041] Step 6: The left horizontal die and the right horizontal die join the action, the left horizontal die moves to the right to contact the preform, at the same time, the right horizontal die moves to the left to contact the preform, the left horizontal die and the right horizontal die move 107mm to the target position respectively, completing the ring upsetting of the preform to obtain the preformed forging.

[0042] Step 7: The left horizontal mold and the right horizontal mold make a return motion respectively, and stop after reaching the specified position. The left horizontal punch and the right horizontal punch join the action. The left horizontal punch moves to the right and contacts the inner hole of the preform. At the same time, the right horizontal punch moves to the left and contacts the inner hole of the preform. The left and right horizontal punches move 270mm to the target position respectively to shape the inner hole of the preform.

[0043] Step 8: Finally, control the left horizontal punch, the right horizontal punch, the left horizontal die, the right horizontal die and the upper die to return to the initial positions to obtain the required precision rotor adapter shaft forging.

[0044] If the traditional die forging method is used, the weight of the forging is 1255Kg, the weight of the feed is 1380Kg, and it needs 2 rounds of blank making, 1 round of pre-forging, and 1 round of final forging. After die forging, the flash needs to be removed. However, by adopting the technology of the present invention, the weight of the forging can be reduced from 1255Kg to 905Kg, a decrease of 27.9%; the feed weight is reduced from 1380Kg to 910Kg, a decrease of 34.1%; the number of forging rounds is reduced from 4 rounds to 1 round, a decrease of 75%; after die forging, only the burrs need to be polished, and there is no need to remove the flash; the material cost of a single piece can save 141,000 yuan. According to the annual demand of 50 gas turbines, 7.05 million yuan can be saved each year, which has great economic benefits. It can be seen from the above data that compared with the existing technology, this scheme has significant improvements, and has better processing accuracy, processing efficiency and cost control.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the technical solution. Those skilled in the art should understand that those modifications or equivalent substitutions of the technical solution of the present invention that do not depart from the purpose and scope of the technical solution should be included in the scope of the claims of the present invention.

Claims

1. A precision forging method for a large high-temperature alloy rotor adapter shaft, characterized in that: The steps include: Step 1: Process the cylindrical blank according to the outer dimensions of the forging; Step 2: Heat the blank to the forging temperature, then take out the blank, cover the surface of the blank with glass powder binder, and then cover it with insulation cotton, and heat and keep the blank warm again for a certain period of time; Step 3: Place the heated blank in the cavity of the lower mold, and then control the upper mold to move downward, and continue to move downward after contacting the blank until the upper mold and the lower mold are closed, completing the pressing action; Step 4: The upper die is kept in a downward pressing state, and then the left horizontal punch is controlled to move to the right to contact the blank, and at the same time, the right horizontal punch is controlled to move to the left to contact the blank; the left and right horizontal punches are continued to be controlled to move to the specified target positions respectively to form the inner cavity of the blank; Step 5: Control the left and right horizontal punches to perform return motion respectively until they return to their initial positions, thereby completing the preparation of the preform with the inner cavity; Step 6: Control the left horizontal die to move rightward until it contacts the preform, and at the same time, control the right horizontal die to move leftward until it contacts the preform, and then simultaneously control the left horizontal die and the right horizontal die to move to the designated target positions respectively, to complete the upsetting of the preform; Step 7: Control the left horizontal die and the right horizontal die to make a return motion respectively, and stop after reaching the specified position, and then control the left horizontal punch to move to the right again and enter the inner hole cavity of the billet. At the same time, control the right horizontal punch to move to the left and enter the inner hole cavity of the billet, until the left and right horizontal punches move to the specified target positions respectively, and complete the shaping of the inner hole cavity of the forging; Step 8: Finally, control the left horizontal punch, the right horizontal punch, the left horizontal die, the right horizontal die and the upper die to return to the initial positions to obtain the required rotor adapter shaft.

2. The method for precision forging of a large high-temperature alloy rotor adapter shaft according to claim 1, characterized in that: The diameter of the cylindrical blank is 0.1-5 mm smaller than the maximum diameter of the inner hole formed after the upper mold and the lower mold are molded together.

3. The method for precision forging of a large high-temperature alloy rotor adapter shaft according to claim 1, characterized in that: The thickness of the thermal insulation cotton covering the surface of the cylindrical blank is 5~10mm.

4. The method for precision forging of a large high-temperature alloy rotor adapter shaft according to claim 1, characterized in that: In step 4, after the left and right horizontal punches move to the specified target position, the spacing between the left and right horizontal punches is 40-60 mm, so that the thickness of the skin between the left inner hole cavity and the right inner hole cavity of the blank is 40-60 mm.

5. The method for precision forging of a large high-temperature alloy rotor adapter shaft according to claim 1, characterized in that: In step 4, the forging load of the billet is 2900 tons.

6. The method for precision forging of a large high-temperature alloy rotor adapter shaft according to claim 1, characterized in that: In step six, the forging load for upsetting is 5000 tons.

7. The method for precision forging of a large high-temperature alloy rotor adapter shaft according to claim 1, characterized in that: In step seven, the forging load for shaping the inner cavity is 800 tons.

8. A precision forging die for a large high-temperature alloy rotor adapter shaft, characterized in that: It includes an upper mold, a lower mold, a left horizontal mold, a right horizontal mold, a left horizontal punch and a right horizontal punch; the shape of the inner hole formed after the upper mold and the lower mold are combined matches the side shape of the rotor adapter shaft to be processed; the left horizontal mold and the right horizontal mold are respectively arranged at the two ends of the lower mold, and their axis lines coincide with the axis line of the inner hole formed after the upper mold and the lower mold are combined, and can slide in the inner hole formed after the upper mold and the lower mold are combined; through holes are opened on the left horizontal mold and the right horizontal mold along their axis lines, and the stamping ends of the left horizontal punch and the right horizontal punch respectively pass through the left horizontal mold and the right horizontal mold and extend into the lower mold, and are respectively connected with the left horizontal mold and the right horizontal mold in a sliding fit.

9. The large high-temperature alloy rotor adapter shaft precision forging die according to claim 8, characterized in that: The end faces of the left horizontal mold and the right horizontal mold extending into the lower mold are both stepped surfaces, wherein the inner ring surface close to the inner side of the end faces of the left horizontal mold and the right horizontal mold protrudes from the outer ring surface close to the outer side, and the thickness of the protruding part is 10~20mm, the area of ​​the inner ring surface is 0.8~1.2 times the area of ​​the outer ring surface, and the connection between the inner ring surface and the outer ring surface is chamfered.

Images