Forging stock manufacturing method of disc-shaped forge piece

Abstract

The invention relates to the technical field of forging, in particular to a forging stock manufacturing method of a disc-shaped forging. Comprising the steps that S1, an initial bar is manufactured, S2, end covers are manufactured according to the size of the bar, S3, the end covers are arranged at the two ends of the bar to form a combined body, and the combined body is placed in a heating furnace to be heated and subjected to heat preservation; s4, taking out the combined body treated in the S3 from the heating furnace, placing the combined body on a workbench of a hydraulic machine for upsetting cakes, and then cooling the cakes to room temperature; s5, the combined body treated in the step S4 is placed in a heating furnace to be heated and subjected to heat preservation; and after heat preservation, placing in die forging equipment for die forging forming. According to the technical scheme, the forging stock manufacturing method for the disc-shaped forge piece comprises the steps that end covers are arranged at the two ends of a bar, the end covers can deform along with deformation of the bar in the cake upsetting and die forging forming process, the end covers wrap the bar all the time, it is guaranteed that the bar area does not make contact with a hydraulic machine or a die forging machine, and the yield of the disc-shaped forge piece is increased. And coarse grain layers on the bars are reduced, and the quality of formed forgings is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of forging, and particularly to a method for manufacturing a forging blank of a disc-shaped forging. Background Art

[0002] The superalloy disc is an important part of aeroengines and heavy-duty land gas turbines, and is a core key component of gas turbines. To achieve high performance of the engine, it is necessary to increase the service temperature of the core engine, which requires that the disc-shaped forging has excellent high-temperature creep and creep properties, and this in turn requires that the grain structure of the material must be uniform and fine. The mainstream manufacturing method of disc-shaped forgings widely used in industry is to forge a blank and then assemble it into a finished product after precision machining. In the actual production process, due to the influence of the die temperature and the deformation mode, a coarse grain layer will appear on the surface of the formed disc-shaped forging. The appearance of the coarse grain layer will seriously affect the quality of the disc-shaped forging, reduce the material utilization rate of the product, and increase the manufacturing cost of the product.

[0003] The reasons for the appearance of the coarse grain layer are as follows: First, the temperature of the traditional die forging die is much lower than the temperature of the blank. When the two come into contact, the temperature of the blank surface will drop rapidly, which will cause insufficient dynamic recrystallization of the material and form coarse grains. Second, in the traditional die forging process of blank making, the bar stock is upset into a cake blank, and then the cake blank is die forged and formed. In this process of die forging the cake blank, small deformation zones will be formed on the upper and lower surfaces, and these two zones often overlap, further deteriorating the structure and forming a coarse grain layer. Figure 1 The grain situation of the alloy disc forging manufactured by the existing process is shown. Figure 1 The left figure shows the results of sampling from top to bottom in area 2. The higher the grain grade is, the closer it is to the center of the forging, and coarse grains of grade 5 appear on the surface of the forging. Figure 1 The right figure shows the results of sampling from top to bottom in area 1. The higher the grain grade is, the closer it is to the center of the forging, and coarse grains of grade 5 appear on the surface of the forging. Figure 1 The middle figure shows fine grains with a grain grade of 10 in the center of the forging. The existing solution is to lay a layer of heat insulation felt on the surface of the forging die, but the effect is not significant because the heat insulation felt cannot deform plastically with the forging and will crack and break, resulting in a large amount of coarse grain layer on the surface of the forging. Another solution is isothermal forging or hot die forging, which requires large-scale transformation of traditional forging equipment to add heating and heat insulation equipment, greatly increasing the manufacturing cost. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for manufacturing a forging blank of a disc-shaped forging, which is used to reduce the generation of the coarse grain layer and improve the quality of the forging.

[0005] The technical solution adopted by the present invention to solve its technical problem is a method for manufacturing a forging blank of a disc-shaped forging, including the following steps:

[0006] S1: Manufacture a bar stock with a diameter a1 and a length a2 in millimeters (mm). The maximum diameter of the final forging is a3 and the thickness is a4, both in mm.

[0007] S2: Manufacture end caps according to the dimensions of the bar stock. The diameter of the end cap is the same as that of the bar stock, and the thickness n of the end cap is n = 21 + 0.02a3 - 0.04a1.

[0008] S3: Coaxially arrange the end caps at both ends of the bar stock to form an assembly. The lower surface of the upper end cap is in close contact with the upper surface of the bar stock, and the upper surface of the lower end cap is in close contact with the lower surface of the bar stock. Then place the assembly in a heating furnace, heat it to a specified temperature and hold for a specified time. The heating temperature is 1000 to 1040 °C, and the holding time T1 is calculated as follows:

[0009] T1 = f * H, in minutes (min), where f is the heating coefficient with a value range of 0.2 to 0.8, and H is the maximum cross-sectional thickness of the assembly in mm.

[0010] S4: Take out the assembly processed in S3 from the heating furnace and place it on the working table of a hydraulic press for upsetting. The transfer time of the assembly is ≤ 50 s, and the upsetting rate is 5 mm / s to 10 mm / s. Upset the assembly to the required process dimensions and then cool it to room temperature. The working table needs to be preheated to a temperature in the range of 350 to 500 °C.

[0011] S5: Place the assembly processed in S4 in a heating furnace, heat it to a specified temperature and hold for a specified time. The heating temperature is 1000 to 1040 °C, and the holding time T2 is calculated as follows: T2 = f * D, in minutes (min), where f is the heating coefficient with a value range of 0.2 to 0.8, and D is the maximum cross-sectional thickness of the assembly processed in S4 in mm.

[0012] After holding, place the assembly into the die for a disk-shaped forging in a die forging equipment to perform die forging forming. The die needs to be preheated to a temperature in the range of 350 to 500 °C, and the die forging pressing rate is ≥ 5 mm / s.

[0013] S6: Use numerical simulation to determine the state of the assembly after being processed in steps S4 and S5, determine the area where the end cap is located, and use machining equipment to remove the area where the end cap is located.

[0014] Furthermore, coaxially arrange a first sleeve on the end cap, provide an internal thread on the inner wall of the first sleeve, and provide an external thread on the outer circumference of the bar stock that mates with the internal thread.

[0015] Furthermore, coaxially sleeved a second sleeve outside the bar stock. The second sleeve is fixedly connected to the end caps at both ends of the bar stock respectively, and the wall thickness s of the second sleeve is s = 8 + 0.1a4.

[0016] Further, the material of the bar stock is IN718 / GH4169, and the material of the end cap is 2Cr13.

[0017] The beneficial effects of the present invention are as follows: By arranging end caps at both ends of the bar stock, the end caps can deform along with the deformation of the bar stock during the processes of upsetting and die forging. The end caps always cover the bar stock, ensuring that the bar stock area does not come into contact with the hydraulic press or the die forging machine, reducing the heat loss of the bar stock, decreasing the generation of coarse grain layers on the bar stock, and improving the quality of the forged parts after forming. Description of the Drawings

[0018] Figure 1 is the grain distribution diagram of the forged part manufactured by the existing process;

[0019] Figure 2 is the schematic diagram of the present invention;

[0020] Figure 3 is the schematic diagram of the connection of the end cap, the first sleeve and the bar stock of the present invention;

[0021] Figure 4 is the schematic diagram of the connection of the end cap, the second sleeve and the bar stock of the present invention;

[0022] Figure 5 is Figure 2 the schematic diagram of the upsetting process of the embodiment of

[0023] Figure 6 is Figure 2 the schematic diagram of the upsetting process of the embodiment of

[0024] Figure 7 is Figure 2 the distribution diagram of the end cap and the bar stock after numerical simulation of the embodiment of

[0025] Reference Signs: 1 - bar stock; 2 - end cap; 3 - first sleeve; 4 - second sleeve. Detailed Embodiments

[0026] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, in which the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0027] As Figures 2 - 7 shown, a method for manufacturing a forging blank of a disc-shaped forging of the present invention includes the following steps:

[0028] A method for manufacturing a forging blank of a disc-shaped forging, characterized in that it includes the following steps:

[0029] S1: Manufacture the bar stock 1 with a diameter a1 and a length a2 in mm. The maximum diameter of the final forging is a3 and the thickness is a4 in mm. Determine the diameter a1 and the length a2 of the bar stock 1 according to the weight of the disc-shaped forging. The material of the bar stock 1 is IN718 / GH4169. According to the target weight of the disc-shaped forging, determine the diameter a1 and the length a2 of the bar stock 1 through the volume formula V = π×(a1 / 2) 2 ×c×ρ (where ρ is the material density). The maximum diameter of the final forging is a3 and the height is a4 in mm;

[0030] S2: Manufacture the end caps 2 according to the dimensions of the bar stock 1. The diameter of the end cap 2 is the same as that of the bar stock. The thickness n of the end cap 2 = 21 + 0.02a3 - 0.04a1. The end cap 2 can completely cover the upper and lower surfaces of the bar stock 1, and the thickness n = 21 + 0.02a3 - 0.04a1 satisfies that it can deform with the deformation of the bar stock 1 during the processes of upsetting and die forging and always covers the upper and lower end faces of the bar stock 1.

[0031] S3: Coaxially set the end caps 2 at both ends of the bar stock 1 to form an assembly. The lower surface of the upper end cap 2 is closely attached to the upper surface of the bar stock 1, and the upper surface of the lower end cap 2 is closely attached to the lower surface of the bar stock 1. Place the assembly in a heating furnace for heating and holding for a specified time. The heating temperature is 1000 to 1040 °C, and the holding time T1 is calculated as follows;

[0032] T1 = f*H in minutes, where f is the heating coefficient with a value of 0.2 - 0.8, and H is the maximum cross-sectional thickness of the assembly in mm. Here, the cross-section is the cross-section of the assembly, and the shape cut out is circular.

[0033] The end cap 2 can be fixedly connected to the two end faces of the bar stock 1 by welding. The material of the end cap 2 is selected as 2Cr13, which is a martensitic stainless steel, resistant to high-temperature oxidation and with a low cost. Machine it to the designed dimensions by turning to ensure the end face is flat. Place the assembly in a heating furnace and hold it at 1000 - 1040 °C for T1 minutes. For example, if the cross-sectional thickness of the assembly is 200 mm, then the holding time is 40 min - 160 min to make the material uniformly austenitized.

[0034] S4: Take out the assembly processed in S3 from the heating furnace and place it on the workbench of the hydraulic press for upsetting. The transfer time of the assembly ≤ 50 s, and the upsetting rate is 5 mm / s to 10 mm / s. Upset the assembly to the process requirements dimensions and then cool it to room temperature. The workbench needs to be preheated, and the preheating temperature is 350 - 500 °C. Control the transfer time within 50 S. At the same time, preheat the workbench, which can reduce heat loss.

[0035] S5: Place the assembly after being processed in S4 into a heating furnace, heat it, and hold for a specified time; the heating temperature is 1000 to 1040 °C, and the holding time T2 is calculated as follows: T2 = f * D, with the unit of min, where f is the heating coefficient, taking a value of 0.2 to 0.8, and D is the maximum cross-sectional thickness of the assembly after being processed in S4, with the unit of mm;

[0036] After holding, place the assembly into the die for disk forgings of a die forging equipment, and perform die forging on the assembly; the die needs to be preheated, and the preheating temperature is 350 to 500 °C, and the die forging pressing rate ≥ 5 mm / s.

[0037] S6: Use numerical simulation to simulate the state of the assembly after being processed in steps S4 and S5, determine the area where the end cover 2 is located, and use a machining device to remove the area where the end cover 2 is located.

[0038] As a preferred embodiment, further, refer to Figure 3 ., coaxially arrange a first sleeve 3 on the end cover 2, provide an internal thread on the inner wall of the first sleeve 3, and provide an external thread on the outer periphery of the bar stock 1 for mating with the internal thread. Coaxially install the first sleeve 3 on the end cover 2, the inner diameter of the first sleeve 3 is equal to the diameter of the bar stock 1, machine the internal thread on the inner wall of the first sleeve 3, and machine matching external threads at both ends of the bar stock 1. During assembly, the threaded connection between the end cover 2 and the bar stock 1 is realized by screwing, enhancing the anti-eccentricity ability of the assembly during upsetting. As Figure 6 shown, after simulating using a numerical simulation software, the dark blue area is the area where the end cover 2 is located, and subsequently, the area where the end cover 2 is located can be removed using a machining device.

[0039] As a preferred embodiment, further, refer to Figure 4 ., coaxially sleeved with a second sleeve 4 outside the bar stock 1, and the second sleeve 4 is fixedly connected to the end covers 2 at both ends of the bar stock 1 respectively. Sleeve the second sleeve 4 outside the bar stock 1, the inner diameter of the second sleeve 4 is equal to the diameter of the bar stock 1, the length of the second sleeve 4 is the sum of the length of the bar stock 1 and the lengths of the end covers on both sides, and the end cover 2 is welded and fixed on the inner wall of the second sleeve. Such a setting can restrict the radial expansion of the bar stock 1, reduce the loss of end materials during upsetting, improve the material utilization rate, and at the same time can ensure that the outer surface of the bar stock 1 does not contact the external air, reducing the temperature loss of the bar stock 1.

[0040] Example 1

[0041] Cut a bar stock made of IN718 / GH4169 with a diameter of 300 mm into bar segments with a length of 600 mm, machine the end faces flat by turning, and chamfer the end faces smoothly with a chamfer value of R25, which is called the bar stock for forging disk forgings. The final forging has a diameter of 700 mm and a thickness of 150 mm.

[0042] A bar with a material of 2Cr13 and a diameter of 300 mm is cut into circular discs with a thickness of 23 mm. The surface of the circular disc is made neat through turning to obtain an end cover. A first sleeve is coaxially welded to the end cover. The inner diameter of the first sleeve is 300 mm and the outer diameter is 346 mm. Internal threads are machined on the inner wall of the first sleeve, and matching external threads are machined at both ends of the bar stock. After assembly, a combined body is formed.

[0043] Then the above combined body is placed in a heating furnace and heated to 1000 °C, with a holding time of 69 min. Then, within 50 s, the heated combined body is placed on a hydraulic press to carry out upsetting work. The upsetting rate is 5 mm / s. The entire combined body is upset to a height of 300 mm (the height before upsetting is 646 mm) and a diameter of 550 mm. Then it is cooled to room temperature, and after appearance inspection, it is heated again to 1000 °C and held for 110 min. After holding, the combined body is taken out of the heating furnace and placed in a disk-shaped forging die. The die needs to be preheated, and the preheating temperature is 350 °C. The die forging pressing rate is ≥5 mm / s. It is struck with a die forging hammer according to the number of process hammer blows until it is formed.

[0044] A numerical simulation software is used to simulate the metal flow after upsetting and die forging, and identify the regions of the end cover and the first sleeve. This region is cut off by a CNC milling machine, and the main body of the disk-shaped forging is retained, and finally a net-shaped forging is obtained.

[0045] Example 2

[0046] A bar with a material of IN718 / GH4169 and a diameter of 300 mm is cut into bar segments with a length of 600 mm. The end faces are made flat through turning, and the end faces are chamfered smoothly with a chamfer value of R25, which is called the forging disk-shaped forging bar stock. The diameter of the final forging is 700 mm and the thickness is 150 mm.

[0047] A bar with a material of 2Cr13 and a diameter of 300 mm is cut into circular discs with a thickness of 23 mm. The surface of the circular disc is made neat through turning to obtain an end cover. A first sleeve is coaxially welded to the end cover. The inner diameter of the first sleeve is 300 mm and the outer diameter is 346 mm. Internal threads are machined on the inner wall of the first sleeve, and matching external threads are machined at both ends of the bar stock. After assembly, a combined body is formed.

[0048] Then put the above combination into a heating furnace, heat it to 1040 °C, keep it warm for 277 min, and then place the heated combination on a hydraulic press within 50 s to carry out upsetting work. The upsetting rate is 10 mm / s. Upset the entire combination to a height of 300 mm (the height before upsetting is 646 mm) and a diameter of 550 mm, and then cool it to room temperature for appearance inspection and then heat it again to 1040 °C and keep it warm for 440 min. After heat preservation, take out the combination from the heating furnace and place it in a disk-shaped forging die. The die needs to be preheated, and the preheating temperature is 500 °C. The die forging pressing rate is ≥5 mm / s. Use a die forging hammer to strike according to the number of process hammer blows until it is formed.

[0049] Use numerical simulation software to simulate the metal flow after upsetting and die forging, and identify the areas of the end cover and the first sleeve. Cut off this area by a CNC milling machine, keep the main body of the disk-shaped forging, and finally obtain a net-shaped forging.

[0050] Example 3

[0051] Cut a bar with a material of IN718 / GH4169 and a diameter of 300 mm into bar segments with a length of 600 mm. Plane the end face by turning, and chamfer the end face smoothly. The chamfer value is R25, which is called the forging bar stock of the disk-shaped forging. The diameter of the final forging is 700 mm and the thickness is 150 mm.

[0052] Cut a bar with a material of 2Cr13 and a diameter of 316 mm into circular wafers with a thickness of 23 mm. Make the surface of the circular wafer clean by turning to obtain an end cover. The inner diameter of the second sleeve is 300 mm, the outer diameter is 346 mm, and the length is 646 mm. Place the bar stock in the second sleeve and weld it to the end cover by welding to form a combination.

[0053] Then put the above combination into a heating furnace, heat it to 1000 °C, keep it warm for 69 min, and then place the heated combination on a hydraulic press within 50 s to carry out upsetting work. The upsetting rate is 5 mm / s. Upset the entire combination to a height of 300 mm (the height before upsetting is 646 mm) and a diameter of 550 mm, and then cool it to room temperature for appearance inspection and then heat it again to 1000 °C and keep it warm for 110 min. After heat preservation, take out the combination from the heating furnace and place it in a disk-shaped forging die. The die needs to be preheated, and the preheating temperature is 350 °C. The die forging pressing rate is ≥5 mm / s. Use a die forging hammer to strike according to the number of process hammer blows until it is formed.

[0054] Use numerical simulation software to simulate the metal flow after upsetting and die forging, and identify the areas of the end cover and the second sleeve. Cut off this area by a CNC milling machine, keep the main body of the disk-shaped forging, and finally obtain a net-shaped forging.

[0055] Example 4

[0056] A bar made of IN718 / GH4169 with a diameter of 300 mm is cut into bar segments with a length of 600 mm. The end faces are flattened by turning, and the end faces are chamfered smoothly with a chamfer value of R25, which is called the bar stock for the forged disk-shaped forging. The diameter of the final forging is 700 mm, and the thickness is 150 mm.

[0057] A bar made of 2Cr13 with a diameter of 316 mm is cut into circular wafers with a thickness of 23 mm. The surface of the wafer is made clean by turning to obtain an end cover. The inner diameter of the second sleeve is 300 mm, the outer diameter is 346 mm, and the length is 646 mm. The bar stock is placed in the second sleeve and welded to the end cover by welding to form a combined body.

[0058] Then the above combined body is put into a heating furnace, heated to 1040 °C, and held for 277 min. Then, within 50 s, the heated combined body is placed on a hydraulic press to carry out upsetting work. The upsetting rate is 10 mm / s. The whole combined body is upset to a height of 300 mm (the height before upsetting is 646 mm) and a diameter of 550 mm. Then it is cooled to room temperature for appearance inspection and then heated again to 1040 °C and held for 440 min. After holding, the combined body is taken out of the heating furnace and placed into a disk-shaped forging die. The die needs to be preheated, and the preheating temperature is 500 °C. The die forging pressing rate is ≥5 mm / s. A die forging hammer is used to strike according to the process number of blows until it is formed.

[0059] Use numerical simulation software to simulate the metal flow after upsetting and die forging, and identify the areas of the end cover and the second sleeve. Cut off these areas by a CNC milling machine, and retain the main body of the disk-shaped forging to finally obtain a net-shaped forging.

[0060] Comparative Example 1

[0061] A bar made of IN718 / GH4169 with a diameter of 300 mm is cut into bar segments with a length of 600 mm. The end faces are flattened by turning, and the end faces are chamfered smoothly with a chamfer value of R25, which is called the initial bar segment for the forged disk-shaped forging.

[0062] The bar stock is put into a heating furnace, heated to 1000 °C, and held for 60 min. Then it is placed on a hydraulic press to carry out upsetting work. The whole combined body is upset to a height of 300 mm (the height before upsetting is 600 mm) and a diameter of 550 mm. Then it is cooled to room temperature for appearance inspection and then heated again to 1000 °C and held for 110 min. The bar stock is taken out of the heating furnace and placed into a disk-shaped forging die, and a die forging hammer is used to strike according to the process number of blows until it is formed.

[0063] Comparative Example 2

[0064] A bar made of IN718 / GH4169 with a diameter of 300 mm is cut into bar segments with a length of 600 mm. The end faces are flattened by turning, and the end faces are chamfered smoothly with a chamfer value of R25, which is called the initial bar segment of the forged disc forging.

[0065] The bar stock is placed in a heating furnace, heated to 1040 °C, and held for 240 min. Then it is placed on a hydraulic press for upsetting work. The entire assembly is upset to a height of 300 mm (the height before upsetting is 600 mm) and a diameter of 550 mm. Then it is cooled to room temperature, inspected for appearance, and reheated. It is heated to 1040 °C and held for 440 min. The bar stock is taken out of the heating furnace and placed in a disc forging die, and struck with a die forging hammer according to the number of process hammer blows until it is formed.

[0066] Compare Examples 1 to 4 with Comparative Examples 1 and 2, and respectively detect the grain size of the forgings after completion. As can be seen from the following table data, the process of the present invention can significantly improve the grain size of the disc forgings.

[0067]

[0068]

[0069] The embodiments of this specific implementation manner are all preferred embodiments of the present invention, and do not limit the protection scope of the present invention accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for manufacturing a forging blank of a disc-shaped forging, characterized in that, It includes the following steps: S1: Manufacture a bar stock (1) with a diameter a1 and a length a2 of the bar stock (1). The maximum diameter of the final forging is a3 and the thickness is a4, all in mm; S2: Manufacture an end cap (2) according to the dimensions of the bar stock (1), where the diameter of the end cap (2) is the same as that of the bar stock, and the thickness n of the end cap (2) = 21 + 0.02a3 - 0.04a1; S3: Coaxially arrange the end caps (2) at both ends of the bar stock (1) to form an assembly. The lower surface of the upper end cap (2) is in close contact with the upper surface of the bar stock (1), and the upper surface of the lower end cap (2) is in close contact with the lower surface of the bar stock (1); and place the assembly in a heating furnace for heating and holding for a specified time. The heating temperature is 1000 to 1040 °C, and the holding time T1 is calculated as follows; T1 = f * H, in minutes, where f is the heating coefficient with a value of 0.2 to 0.8, and H is the maximum cross-sectional thickness of the assembly, in mm; S4: Take out the assembly processed in S3 from the heating furnace and place it on the workbench of a hydraulic press for upsetting. The transfer time of the assembly ≤ 50 s, the upsetting rate is 5 mm / s to 10 mm / s. Upset the assembly to the process requirement dimensions and then cool it to room temperature; the workbench needs to be preheated, and the preheating temperature is 350 to 500 °C; S5: Place the assembly processed in S4 in a heating furnace for heating and holding for a specified time; the heating temperature is 1000 to 1040 °C, and the holding time T2 is calculated as follows; T2 = f * D, in minutes, where f is the heating coefficient with a value of 0.2 to 0.8, and D is the maximum cross-sectional thickness of the assembly processed in S4, in mm; After holding, place the assembly into the die for a disk-shaped forging in a die forging equipment to perform die forging forming on the assembly; the die needs to be preheated, and the preheating temperature is 350 to 500 °C, and the die forging pressing rate ≥ 5 mm / s; S6: Use numerical simulation to determine the area where the end cap (2) is located for the state of the assembly after being processed in steps S4 and S5, and use a machining device to remove the area where the end cap (2) is located.

2. The forging blank manufacturing method of a disc-shaped forging as described in claim 1, characterized in that Coaxially arrange a first sleeve (3) on the end cap (2), provide an internal thread on the inner wall of the first sleeve (3), and provide an external thread on the outer circumference of the bar stock (1) that is used in cooperation with the internal thread.

3. The forging blank manufacturing method of a disc-shaped forging as claimed in claim 1, characterized in that, Coaxially sleeved with a second sleeve (4) outside the bar stock (1), and the second sleeve (4) is fixedly connected to the end caps (2) at both ends of the bar stock (1) respectively. The wall thickness s of the second sleeve (4) = 8 + 0.1a4.

4. The forging blank manufacturing method of a disc-shaped forging as described in claim 1, characterized in that, The material of the bar stock (1) is IN718 / GH4169, and the material of the end cap (2) is 2Cr13.

Images