Forging method for high-temperature alloy disk-shaft integrated component and die for forming

Abstract

The present invention relates to a forging method for a high-temperature alloy disk-shaft integrated component and a die for forming. The forging method includes the following steps: after spraying a lubricant on a cylindrical blank, putting it into a forging die for pre-forging, then performing a single drawing on the rod part of the pre-forged part to obtain a drawn pre-forged part, and using ultrasonic inspection technology to detect it. Then, removing the flash of the drawn pre-forged part and spraying the lubricant again for heating, and finally performing final die forging in the die to obtain a final forging. Again, using ultrasonic inspection technology to check the quality of the obtained disk-shaft part. The present invention uses the same die for two upsetting and extrusion forming operations. The second forming adds a detachable fillet ring on the basis of the first forming, relieving the tensile stress and shear stress of the material flow at the step during the first forming process. At the same time, a compressive stress is generated at the step during the second forming, which can reduce the possibility of damage and cracks in the transition zone of the formed disk-shaft part and make the grains in the transition zone more uniform.

Description

Technical Field

[0001] The present invention belongs to the technical field of forging, and particularly relates to a forging method for forming a high-temperature alloy disk-shaft integrated component and a die for forming. Background Art

[0002] With the increase in the thrust-to-weight ratio of aero-engines, more and more components in the engine adopt an integral structure. As an important load-bearing component in the engine, the component with a disk-shaft integrated structure has a relatively complex structure and is difficult to process. The existing processing methods generally use a press to extrude, forming the rod part by a single upsetting method, extruding the rod part while upsetting the disk body. Therefore, high requirements are imposed on the tonnage and accuracy of the equipment. At the same time, due to the large difference in the diameter dimensions between the disk and the shaft of the disk-shaft component, during the upsetting and extrusion forming process, large tensile stress and shear stress will be generated when the material flows at the step of the die, which will further cause damage and cracks at the connection of the disk-shaft component, and lead to the formation of mixed grains in this area, greatly reducing the mechanical properties of the disk-shaft component, and further affecting the comprehensive performance and service life of the produced disk-shaft integrated component. Therefore, the forming of the disk-shaft integrated component has high requirements for forging technology. Summary of the Invention

[0003] Based on the existing forging technology, the present invention provides a forging method for reducing the tensile stress and shear stress at the connection of a high-temperature alloy disk-shaft component and forming a disk-shaft integrated component with more uniform grains in the disk-shaft transition zone, and achieves this goal by designing the die structure required for forging.

[0004] To achieve the above object, the present invention provides a method for reducing the concentrated stress during forging of a disk-shaft integrated component, including the following steps:

[0005] (1) Cut the bar on a sawing machine to obtain an initial blank, and then turn the two end faces of the initial blank into rounded corners on a lathe.

[0006] (2) Spray a lubricant on the obtained blank, heat the blank, provide a set of dies on a forging press, first perform a first preforming on the blank. When preforming, the rounded corner pad ring is not assembled to the die, that is, only the upper die and the lower die are used for preforming. There is a smooth curved surface with a large curvature in the preforming die cavity, which can reduce the tensile stress and shear stress suffered by the blank during forming and avoid the generation of cracks. Then put the blank into the die cavity, apply pressure to the upper die through the forging press, so that the blank is forged and formed in the cavity to form a pre-forged part.

[0007] (3) Heat the obtained pre-forged part in a furnace, and then perform a single drawing on its rod part to obtain a drawn pre-forged part. This drawing is for the next final forging to be able to use the original preforming die in cooperation with the rounded corner pad ring for forming, so as to reduce the cost of the die.

[0008] (4) The drawn pre-forgings are inspected by ultrasonic inspection technology. This method can ensure that the surface of the drawn pre-forgings is not damaged, and then the internal cracks can be effectively detected, so that the structure is not damaged and the quality can be identified at the same time.

[0009] (5) A layer of glass lubricant is sprayed on the surface of the drawn pre-forgings, and a thicker layer of glass lubricant is sprayed at the intersection of the disc and the rod. Then it is heated in an electric furnace. Next, a fillet pad ring is placed on the lower die of the pre-forming die placed in step (2). The heated drawn pre-forgings are placed into this set of dies, and pressure is applied to the upper die by a forging press to perform die forging forming to form the final forgings. During this forming process, since a curved surface is formed at the intersection of the disc and the rod after the first pre-forging forming, this forming can effectively reduce the tensile stress and shear stress in the disc-shaft transition zone, and can effectively avoid the occurrence of cracks at the disc-rod junction.

[0010] (6) The disc-shaft final forgings are air-cooled, and then the final forgings are inspected to check whether the dimensions of the disc shaft meet the requirements.

[0011] (7) Finally, the final forgings are inspected by ultrasonic inspection technology to check whether there are cracks in the disc-shaft transition zone.

[0012] On the other hand, the present invention also provides a die for forming a disc-shaft integrated component, which is used when forging a disc-shaft integrated component by using the above forging forming method. The disc-shaft integrated component includes a disc body and a rod body integrally formed. The forming die includes an upper die, a lower die and a fillet pad ring. The upper die includes an upper frustum and a lower frustum, and the diameter of the upper frustum is larger than that of the lower frustum; the outer shape of the lower die is cylindrical, and a cavity is provided inside the lower die. The upper part of the cavity is a cylindrical cavity, and the size of the cavity matches that of the lower frustum of the upper die. A curved surface is provided at the lower part of the cavity, and the diameter of the lower end surface is smaller than that of the upper end surface; the size of the outer curved surface of the fillet pad ring matches the size of the curved surface at the lower part of the cavity, and a cylindrical cavity is provided inside the fillet pad ring; the fillet pad ring is detachably nested in the lower part of the cavity in the lower die.

[0013] Further, the diameter of the cavity inside the fillet pad ring is smaller than the diameter of the lower end surface of the cavity inside the lower die.

[0014] Further, a fillet is provided at the intersection of the upper end surface of the fillet pad ring and the cavity inside the fillet pad ring.

[0015] Advantages of the present invention:

[0016] The present invention aims to reduce the tensile stress and shear stress in the transition region between the disk and the shaft during the forging of disk-shaft integrated components, and specifically provides a forging method and a die. By using the same die for upsetting and extruding twice, a detachable fillet ring is added in the second forming process on the basis of the first forming process. This forming process can greatly relieve the tensile stress and shear stress of the material flowing at the step during the first forming process. At the same time, compressive stress is generated in the material at the step during the second forming process, thereby greatly reducing the possibility of damage and cracks in the transition region of the formed disk-shaft component, and forming a more uniform grain in the transition region. The use of the detachable fillet ring saves die costs and reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic cross-sectional structure view of the disk-shaft integrated component in the embodiment;

[0018] Figure 2 It is a schematic cross-sectional structure view of the initial blank obtained after turning in the embodiment;

[0019] Figure 3 It is a schematic cross-sectional structure view of the overall die in the embodiment;

[0020] Figure 4 It is a schematic diagram of the operation process of the overall die in the embodiment.

[0021] In the figure: 1 - disk-shaft integrated component, 2 - disk body, 3 - rod body, 4 - upper die, 5 - lower die, 6 - fillet ring. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] In order to more clearly understand the above objects, features and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0023] Such as Figure 3The die for forming the integrated disk and shaft component shown is used when forging the integrated disk and shaft component 1. The integrated disk and shaft component 1 includes a disk body 2 and a rod body 3 formed integrally. The forming die includes an upper die 4, a lower die 5 and a fillet ring 6. The upper die 4 includes an upper frustum and a lower frustum, and the diameter of the upper frustum is larger than that of the lower frustum. The outer shape of the lower die 5 is cylindrical. There is a cavity in the lower die 5. The upper part of the cavity is a cylindrical cavity, and the size of the cavity matches that of the lower frustum of the upper die 4. The lower part of the cavity is provided with a curved surface, and the diameter of the lower end surface is smaller than that of the upper end surface. The size of the outer curved surface (i.e., the outer fillet) of the fillet ring 6 matches the size of the lower curved surface of the cavity. There is a cylindrical cavity in the fillet ring 6. The fillet ring 6 is detachably nested in the lower part of the cavity in the lower die 5. Among them, the diameter of the cavity in the fillet ring 6 is smaller than the diameter of the lower end surface of the cavity in the lower die 5. A chamfer is provided at the intersection of the upper end surface of the fillet ring 6 and the cavity in the fillet ring 6.

[0024] The whole set of dies is assembled by forging in two steps. When preforming for the first time, the fillet ring 6 does not need to be assembled, and only the upper die 4 and the lower die 5 need to be assembled. After the blank is preformed, the pre-forged part obtained has a curved surface. When finally forming, the fillet ring 6 needs to be assembled into the lower part of the cavity in the lower die 5 and used together with the fillet ring 6 to forge the final forging.

[0025] In order to reduce the tensile stress and shear stress in the transition area between the disk and the shaft during forging of the integrated disk and shaft components, form grains that are more uniform in the transition area, and obtain forgings with good comprehensive properties, the forging and forming method provided by the present invention mainly includes the following steps:

[0026] (1) Cut the bar on a sawing machine to obtain an initial blank, and then turn the two end faces of the initial blank on a lathe to form chamfers (as Figure 2 shown);

[0027] (2) Spray glass lubricant on the surface of the blank with chamfers turned, and heat the blank in an electric furnace;

[0028] (3) Provide a complete set of dies on a forging press. First, preform the blank for the first time. When preforming, the fillet ring 6 does not need to be assembled into the die (as Figure 4 shown in (a)), and only the upper die 4 and the lower die 5 need to be used. There is a smooth curved surface with a large curvature in the cavity of the preforming die, which can reduce the tensile stress and shear force received by the blank during forming and avoid the generation of cracks. Then put the blank into the die cavity, and apply pressure to the upper die 4 through the forging press, so that the blank is forged and formed in the cavity to form a pre-forged part (as Figure 4 shown in (b)). The upper part of the pre-forged part is a larger disk body, and the lower part is a thicker rod body. At this time, a curved surface with a large curvature is formed at the intersection of the disk body and the rod body;

[0029] In this embodiment, the curvature of the lower surface of the inner cavity of the lower die 5 is 1000R - 1500R (that is, the radius of curvature of the surface is 1000 mm - 1500 mm. At this time, the diameter of the disc of the disc-shaft integral forging is 500 mm, and the diameter of the rod is 300 mm). In other embodiments, the curvature of the surface can be adjusted accordingly according to the size of the forging;

[0030] (4) The obtained pre-forging is reheated in a furnace, and then its rod part is drawn once to obtain the drawn pre-forging as shown in Figure 4 (b). This drawing is to enable the final forging forming in the next step to use the original pre-forging die in cooperation with the fillet spacer 6 for forming, so as to reduce the cost of the die;

[0031] (5) The drawn pre-forging is detected by ultrasonic inspection technology. This method can ensure that the surface of the drawn pre-forging is not damaged, and then the internal cracks can be effectively detected, so that the structure is not damaged and the quality can be identified at the same time;

[0032] (6) The flash of the drawn pre-forging is removed, and a layer of glass lubricant is sprayed on the surface of the above-mentioned drawn pre-forging, and a thicker layer of glass lubricant is sprayed at the intersection of the disc and the rod. Then it is heated in an electric furnace;

[0033] (7) The fillet spacer 6 is placed on the lower die 5 placed in step (3). The whole set of dies is as shown in Figure 4 (c). The heated drawn pre-forging is placed into this set of dies. At this time, the rod of the drawn pre-forging is located inside the fillet spacer 6, and the disc of the drawn pre-forging is located on the fillet spacer 6 and inside the lower die 5. Pressure is applied to the upper die 4 by a forging press, so that the upper die 4, the lower die 5, and the fillet spacer 6 jointly apply pressure to the drawn pre-forging for die forging forming to form the final forging (as shown in Figure 4 (d)). In this forming process, since a curved surface is formed at the intersection of the disc and the rod during the first pre-forging forming, this forming can effectively reduce the tensile stress and shear stress in the disc-shaft transition zone and effectively avoid the occurrence of cracks at the disc-rod junction;

[0034] (8) The disc-shaft final forging is air-cooled, and then the final forging is inspected to check whether the dimensions of the disc-shaft meet the requirements;

[0035] (9) Finally, the final forging is detected by ultrasonic inspection technology to check whether there are cracks in the disc-shaft transition zone.

[0036] The present invention addresses the problem of forming and manufacturing a disk-shaft integrated component used in an aeroengine. It is processed by a composite forging method combining two upsetting-extrusion forming processes with free forging, that is, two upsetting-extrusion forming processes are carried out using the same die. In the second forming process, a detachable fillet ring is added on the basis of the first forming process. This forming process can greatly relieve the tensile stress and shear stress of the material flow at the step in the first forming process. At the same time, compressive stress is generated in the material at the step during the second forming process, thereby greatly reducing the possibility of damage and cracks in the transition zone of the formed disk-shaft component, and forming a more uniform grain in the transition zone to ensure obtaining a forging with good comprehensive mechanical properties. The setting of this fillet ring greatly improves the forming quality of the disk-shaft forging. Since the fillet ring needs to bear a large amount of friction and shear force during the forming process, the material selected for it is different from that of the upper and lower dies, which is a superalloy. The material of the upper die can be die steel such as 3Cr2NiMo or 3Cr2W8V, the material of the lower die can be die steel such as 3Cr2NiMo or 3Cr2W8V, and the material of the fillet ring can be die steel such as 4Cr5MoSiV1 or 4Cr13MoV. In addition, the use of the detachable fillet ring saves the die cost, reduces the production cost, and the fillet ring also has the characteristics of convenient processing and disassembly. The disk-shaft integrated component processed by the die and method of the present invention has a compact structure, good rigidity, a long service life, is suitable for high-speed operation, and is beneficial to improving the performance of the engine.

[0037] Those skilled in the art should understand that although the present invention is described in the manner of multiple embodiments, not each embodiment only contains an independent technical solution. Such a description in the specification is only for the sake of clarity. Those skilled in the art should understand the specification as a whole and regard the technical solutions involved in each embodiment as ways that can be combined with each other to form different embodiments to understand the protection scope of the present invention. The above is only the schematic specific implementation manner of the present invention and is not used to limit the scope of the present invention. Any equivalent changes, modifications and combinations made by those skilled in the art without departing from the concept and principle of the present invention shall fall within the protection scope of the present invention.

Claims

1. A forging method for a high-temperature alloy disc-shaft integrated component, wherein the component comprises a disc body and a rod body formed integrally, characterized in that: The forging forming method comprises the following steps: (1) Cut the bar on a sawing machine to obtain an initial blank, and then use a lathe to round the two end faces of the initial blank; (2) Spraying lubricant on the obtained blank and heating the blank, providing a set of dies on a forging press, first preforming the blank, during preforming, the die does not need to be equipped with a fillet gasket, only an upper die and a lower die are needed, a smooth curved surface with a large curvature exists in the cavity of the preforming die, and the curvature radius of the curved surface is 1000 mm to 1500 mm, which can reduce the tensile stress and shear force of the blank during forming and avoid the generation of cracks; placing the blank into the die cavity, applying pressure to the upper die through the forging press, so that the blank is forged and formed in the cavity to form a preforged part; (3) The obtained pre-forged piece is reheated in the furnace, and then the rod portion is stretched once to obtain a stretched pre-forged piece. The stretching is to enable the original pre-forging die to be formed with a rounded corner washer in the next step of final forging, so as to reduce the cost of the die; (4) The drawn pre-forgings are inspected by ultrasonic inspection technology. This method can ensure that the surface of the drawn pre-forgings is not damaged, and then effectively detect the internal cracks, so that the structure is not damaged and the quality can be identified; (5) spraying a layer of glass lubricant on the surface of the above-mentioned drawn pre-forging, and spraying a thicker layer of glass lubricant on the intersection of the coil and rod, and then heating it in an electric furnace; then placing a fillet gasket on the lower die placed in step (2); placing the heated drawn pre-forging into this set of dies, applying pressure to the upper die by a forging press, and performing die forging to form a final forging; in this forming process, since a curved surface is formed at the intersection of the coil and rod after the first pre-forging, the tensile stress and shear force in the transition zone between the coil and shaft are effectively reduced, and the occurrence of cracks at the coil and rod can be effectively avoided; (6) Air cool the final forgings of the disc shaft, and then inspect the final forgings to check whether the disc shaft and dimensions meet the requirements; (7) Finally, the final forgings are inspected using ultrasonic testing technology to check whether there are cracks in the transition zone between the disc and the shaft.

2. A die for forming a disk-shaft integrated component, used when forging a disk-shaft integrated component by the forging forming method according to claim 1, wherein the disk-shaft integrated component comprises a disk body and a rod body formed integrally, characterized in that: The forming mold includes an upper mold, a lower mold and a rounded corner gasket. The upper mold includes an upper cone and a lower cone, and the diameter of the upper cone is larger than the diameter of the lower cone. The lower mold is cylindrical in shape, and a cavity is provided in the lower mold. The upper part of the cavity is a cylindrical cavity, and the size of the cavity matches the lower cone of the upper mold. A curved surface is provided at the lower part of the cavity, and the diameter of the lower end face is smaller than the diameter of the upper end face. The size of the outer curved surface of the rounded corner gasket matches the size of the lower curved surface of the cavity, and a cylindrical cavity is provided in the rounded corner gasket. The rounded corner gasket is detachably nested in the lower part of the cavity in the lower mold.

Images