A method and device for integral forging, spinning and hole expanding of a large-diameter disc-shaped ring forging

Abstract

The application provides a method and device for integral forging forming spinning hole expanding of a large-diameter disc-shaped ring forge piece, and relates to the field of forging technology. The method for integral forging forming spinning hole expanding of the large-diameter disc-shaped ring forge piece comprises the following steps: placing a hollow forge blank on a rotary table; adopting a spreading hammer head to perform spinning hole expanding on the hollow forge blank in a through-center symmetry loading mode; when the inner hole size of the hollow forge blank under the spinning hole expanding reaches a preset threshold value, the spreading hammer head performs eccentric spinning on the hollow forge blank until a disc-shaped ring forge piece with a target size is obtained.

Description

Technical Field

[0001] This invention relates to the field of forging technology, and more specifically, to a method and apparatus for integral forging and spinning to expand holes in large-diameter disc-shaped ring forgings. Background Technology

[0002] In the production of disc ring forgings, the traditional multi-stage reaming process has long faced challenges of low efficiency and unstable forming quality. To address this issue, existing technologies attempt to place the hollow forging billet on a rotary table and utilize the rotational motion of the rotary table combined with an asymmetric loading mode of repeated single-sided pressing of the anvil to perform the reaming operation. However, this asymmetric loading mechanism reveals significant drawbacks in practical applications: the flow distribution of the metal material during forming is extremely uneven, and it is difficult to achieve precise coordinated control of tangential and radial deformation. Due to the significant differences in metal flow resistance in different regions of the forging billet, the material tends to extend unidirectionally along the path of least resistance, requiring multiple repeated pressing and trimming processes to barely achieve the target size requirements. This not only significantly prolongs the overall forging cycle but also results in severely insufficient forming efficiency. Simultaneously, the non-uniform deformation caused by asymmetric forces easily induces forming defects such as uneven wall thickness and end face warping in the disc ring forging, thus forcing subsequent finishing processes to increase allowance requirements, reducing the effective utilization rate of material, and ultimately hindering the improvement of overall process efficiency and the reasonable control of production costs. Summary of the Invention

[0003] The problem this invention addresses is how to improve material utilization to reduce production costs.

[0004] To address the aforementioned problems, this invention provides a method for integral forging and spinning expansion of large-diameter disc-shaped ring forgings, comprising the following steps: Place the hollow forging billet on the rotary table; The hollow forging blank is spun and expanded using a widened hammerhead in a center-symmetric loading mode; When the inner diameter of the hollow forging blank under the spinning expansion reaches a preset threshold, the widening hammer performs eccentric spinning on the hollow forging blank until a disc-shaped ring forging of the target size is obtained.

[0005] Optionally, the over-centrosymmetric loading mode specifically includes: The widening hammerhead passes through the axis of the hollow forging blank; After each downward press of the widening hammer, the rotary table rotates by a preset angle until the inner hole size of the hollow forging billet reaches a preset threshold.

[0006] Optionally, in the over-central symmetric loading mode, the width of the widened hammerhead is greater than the anvil feed amount.

[0007] Optionally, the eccentric spinning specifically includes: Adjust the position of the widening hammer head to deviate from the center of the hollow forging blank; After each downward press of the widening hammer, the rotary table rotates by the same angle until the disc-shaped ring forging of the target size is obtained.

[0008] Optionally, adjusting the position of the widening hammer head specifically includes translating the widening hammer head radially along the hollow forging blank.

[0009] The preset threshold is when the inner hole size is close to the inner hole size of the disc-shaped ring forging and a predetermined allowance is left.

[0010] Optionally, the integral forging and spinning method for large-diameter disc-shaped ring forgings further includes heating, upsetting, and expanding a round bar billet to obtain the hollow forging billet.

[0011] Optionally, the hollow forging billet is heated before being placed on the rotary table.

[0012] Compared with related technologies, the integral forging and spinning expansion method for large-diameter disc-shaped ring forgings of the present invention, through a staged loading mode—first performing spinning expansion under a centrally symmetrical loading mode, and then performing eccentric spinning—effectively improves the problem of uneven metal material flow in traditional processes, achieving coordinated control of tangential and radial deformation. This significantly shortens the forging cycle, improves forming efficiency, and reduces the probability of forming defects such as localized uneven wall thickness and end-face warping in the disc-shaped ring forgings, thereby reducing finishing allowances and improving material utilization.

[0013] In another aspect, the present invention provides a spinning and expanding device for integral forging of large-diameter disc-shaped ring forgings, used to realize the spinning and expanding method for integral forging of large-diameter disc-shaped ring forgings as described above. The spinning and expanding device for integral forging of large-diameter disc-shaped ring forgings includes a widening hammer and a rotary table. The rotary table is used to carry the hollow forging blank and drive the hollow forging blank to rotate. The widening hammer is used to press down on the hollow forging blank through the axis of the hollow forging blank, and is also used to press down on the hollow forging blank away from the axis.

[0014] Optionally, the widening hammerhead includes an upper portion and a lower portion along its height direction, the width of the upper portion being greater than the width of the lower portion, and the lower portion being used for forging the hollow forging blank.

[0015] The integral forging and spinning reaming device for large-diameter disc-shaped ring forgings has all the beneficial effects of the integral forging and spinning reaming method for large-diameter disc-shaped ring forgings, which will not be elaborated here. Attached Figure Description

[0016] Figure 1This is a schematic diagram of the integral forging and spinning hole expansion method for a large-diameter disc-shaped ring forging in an embodiment of the present invention; Figure 2 This is a schematic diagram of the over-centrosymmetric loading mode in an embodiment of the present invention; Figure 3 This is a schematic diagram of eccentric spinning in an embodiment of the present invention.

[0017] Explanation of reference numerals in the attached figures: 1-Hollow forging blank; 2-Rotary table; 3-Expanded hammerhead. Detailed Implementation

[0018] It should be noted that the terms "first," "second," etc., used in the specification and claims of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein.

[0019] Combination Figures 1 to 3 As shown, this embodiment of the invention provides a method for integral forging and spinning to expand the hole of a large-diameter disc-shaped ring forging, including the following steps: Step 1: Place the hollow forging billet 1 on the rotary table 2; Step 2: Use the widened hammer 3 to spin expand the hollow forging blank 1 in a center-symmetric loading mode; Step 3: When the inner hole size of the hollow forging blank 1 under spinning expansion reaches the preset threshold, the widening hammer 3 performs eccentric spinning on the hollow forging blank 1 until a disc-shaped ring forging of the target size is obtained.

[0020] Specifically, the hollow forging billet 1 can be manually placed at the center of the rotary table 2, ensuring that it is aligned with the rotation axis of the rotary table 2. Alternatively, a mechanical clamp or lifting device can be used to lift the hollow forging billet 1 and place it on the rotary table 2, followed by centering by visual inspection or a positioning device.

[0021] Next, since the flow of the metal billet 1 during the forming process is mainly tangential elongation, a widening hammer 3 is used to spin-expand the hollow forging billet 1 using a center-symmetric loading mode. In this stage, the widening hammer 3 is positioned above the central region of the hollow forging billet 1, such as... Figure 2As shown, the hammer 3 presses down vertically, applying pressure to the hollow forging blank 1. Simultaneously, the rotary table 2 rotates via its corresponding drive structure, causing the hollow forging blank 1 to rotate continuously, ensuring that the pressing action of the widening hammer 3 is evenly distributed circumferentially over the hollow forging blank 1. For example, the widening hammer 3 can press down at a constant speed, while the rotary table 2 rotates at a constant angular velocity, thereby achieving radial expansion of the inner hole of the hollow forging blank 1. Alternatively, the widening hammer 3 can perform a periodic pressing action, with the rotary table 2 rotating after each press to ensure that the entire inner hole area is uniformly forged.

[0022] To prevent insufficient inner diameter allowance in the forging billet, when the reaming process continues until the inner diameter of the forging billet is close to the finished product size and a certain allowance is reserved, that is, when the inner diameter of the hollow forging billet 1 under spinning reaming reaches a preset threshold, the forging process enters the second stage, such as... Figure 3 As shown. The preset threshold can be a pre-set inner diameter value, for example, determined by empirical data or calculation. When the inner diameter of the hollow forging blank 1 reaches this value through measurement, the stage transition is triggered. After this, the widening hammer 3 performs eccentric spinning on the hollow forging blank 1 until a disc-shaped ring forging of the target size is obtained. Specifically, the position of the widening hammer 3 is adjusted to deviate from the central axis of the hollow forging blank 1, thereby applying asymmetrical pressure to the hollow forging blank 1 during rotation. For example, the widening hammer 3 can be moved to the eccentric position manually or by a mechanical adjustment device, and then the pressing operation is performed. The rotary table 2 continues to rotate during this stage, while the widening hammer 3 repeatedly presses down at the eccentric position, gradually enlarging the inner diameter of the hollow forging blank 1 and correcting its shape until the required inner and outer diameter dimensions of the disc-shaped ring forging are finally achieved.

[0023] Therefore, in this embodiment, by using a phased loading mode—first performing centrifugal spun forming and then eccentric spun forming—the problem of uneven metal material flow in traditional processes can be effectively improved, achieving coordinated control of tangential and radial deformation. This significantly shortens the forging cycle, improves forming efficiency, and reduces the probability of forming defects such as uneven wall thickness and end face warping in disc ring forgings, thereby reducing finishing allowances and improving material utilization.

[0024] Based on the above embodiments, a process for integral forging of a large-diameter disc-shaped ring is provided, as follows: Step 1: The steel ingot is pre-drawn to a round bar shape of Φ1600mm×4500mm. Then, the entire riser and sprue of the billet are removed by gas cutting. The remaining billet is then divided equally into two round bar forging billets with a size of Φ1600mm×2145mm.

[0025] Step 2: After the round bar forging billet is heated and removed from the furnace, with the sprue end facing downwards, it is upset using a concave upper upsetting plate and platform to achieve a target size of Φ3130mm × 550mm. When the deformation resistance of the round bar forging billet increases and single-sided upsetting becomes difficult to continue, double-sided upsetting can be performed to reduce deformation resistance, effectively promoting the continued uniform diffusion of metal and ensuring that the final size is achieved. After the upsetting process is completed, the forging billet is obtained and transferred to a 10,000-ton hydraulic press. A punch and a special perforator are used to punch an Φ800mm through hole in the center of the forging billet, thus obtaining a hollow forging billet 1.

[0026] Step 3: Place the heated hollow forging billet 1 at the center of the rotary table 2, and use the over-center symmetrical loading mode of the widening hammer 3 (6250mm×550mm×1100mm) to widen and flatten the billet in the thickness direction. The reduction in each pass is controlled within 100mm to balance deformation resistance and ensure controllable metal flow. After each widening reduction, the rotary table 2 rotates 15° before the next pass, ensuring that the widening hammer 3 applies pressure sequentially and evenly at different positions around the forging billet, effectively avoiding excessive local deformation or stress concentration. During this process, under the strong pressure of the widening hammer 3, the forging billet mainly undergoes plastic flow along the length of the widening hammer 3 and perpendicular to the hammer direction. On the one hand, the flow along the length of the widened hammer head 3 directly causes the forging billet to thin in the contact area; on the other hand, due to the principle of constant volume and the constraint of the forging billet's annular structure, some metal is forced to flow radially, resulting in an increase in the outer diameter and a further expansion of the inner diameter, thereby achieving a uniform reduction in the thickness direction and a synchronous and coordinated expansion in the circumferential direction of the forging billet. Repeat the above indexing rotation and pressing operations until the inner diameter approaches the expected target value, at which point processing stops.

[0027] Step 4: When the inner hole size of the hollow forging blank 1 is close to the target value Φ2230mm, to ensure that the inner hole obtains a uniform and sufficient machining allowance, stop using the over-center symmetrical loading mode, adjust the position of the widening hammer 3 to deviate from the center of the hollow forging blank 1 for eccentric spinning, such as... Figure 3As shown. Under this eccentric loading state, the stress and plastic deformation experienced by different regions of the hollow forging billet 1 vary significantly. In the high deformation zone below the widened hammer head 3, the resistance to the metal flow in the outward circumferential direction is relatively small, so a large amount of metal is squeezed towards the outer edge of the forging billet, resulting in an increase in the outer diameter. The inner hole region, being far from the direct high-pressure point, experiences significantly lower compressive stress than the high deformation zone at the outer edge. Therefore, the amount of plastic flow in this region is relatively small and more uniform, resulting in moderate and controllable expansion, thus increasing the inner hole allowance. The eccentric spinning operation is repeated until the outer diameter of the forging reaches a precise 4100mm, and the inner hole shape is round and stable with a diameter of Φ2230mm. At this point, the final external dimensions (outer diameter Φ4100mm × thickness 340mm) and inner hole size (Φ2230mm) of the forging meet the requirements, and the entire forging process is complete, successfully achieving the near-net-shape forming goal of uniformly distributing the allowance across all parts of the forging.

[0028] Optionally, the over-centrosymmetric loading mode specifically includes: The hammer head 3 is widened to pass through the axis of the hollow forging blank 1; After each downward press of the widening hammer 3, the rotary table 2 rotates by a preset angle until the inner hole size of the hollow forging billet 1 reaches the preset threshold.

[0029] Specifically, when the widening hammer 3 performs a pressing operation, its centerline or main working area is aligned with the geometric axis of the hollow forging blank 1. This can be achieved in several ways. For example, a high-precision positioning system (such as a laser alignment instrument or a vision recognition system) can monitor the relative position of the widening hammer 3 and the hollow forging blank 1 in real time and drive a hydraulic or servo mechanism to make fine adjustments to ensure that the center of the hammer coincides with the axis of the forging blank; or, through precise tooling fixtures and guiding mechanisms, the horizontal position of the widening hammer 3 is always kept above the axis of the hollow forging blank 1 when it moves vertically.

[0030] After the widening hammer 3 completes one downward press and deforms the hollow forging billet 1, the rotary table 2 will drive the hollow forging billet 1 to rotate around its axis by a preset angle. This preset angle can be a fixed value, for example, calculated based on the circumference of the forging billet and the width of the hammer, to ensure that the hammer performs overlapping forging of the forging billet at different positions.

[0031] As the widening hammer 3 repeatedly presses down in conjunction with the rotation of the rotary table 2, the inner diameter of the hollow forging billet 1 gradually expands. When this inner diameter reaches a preset threshold, the over-center symmetrical loading mode stops. This preset threshold is usually determined based on the inner diameter of the final disc-shaped ring forging and the machining allowance required for the subsequent eccentric spinning stage. For example, the inner diameter can be monitored in real time by an online measurement system (such as a laser diameter gauge or a contact probe). When the measured value reaches or exceeds the preset threshold, the control system issues a command to stop the current loading mode; alternatively, it can be indirectly controlled by a preset number of forging passes or total pressing amount. When the preset number of passes or pressing amount is reached, the inner diameter is considered to have reached the threshold.

[0032] Thus, by precisely positioning the widening hammer 3 at the axis of the hollow forging billet 1, the forging load is ensured to be evenly distributed radially, avoiding localized stress concentration caused by loading position deviation. By introducing the preset angle rotation mechanism of the rotary table 2, the widening hammer 3 can perform continuous circumferential uniform forging of the forging billet. Through the cyclical pressing and rotation, the metal material is forced to achieve symmetrical and uniform flow in the radial direction, thereby effectively avoiding non-uniform deformation caused by differences in material flow resistance before reaching the preset inner hole size threshold. This control method not only ensures that the hollow forging billet 1 has good geometric symmetry before entering the eccentric spinning stage, but also improves the stability and controllability of the overall forging process through standardized process paths, laying a solid foundation for the forming quality and efficiency of the subsequent eccentric spinning stage.

[0033] Optionally, in the over-central symmetric loading mode, the width of the extended hammer 3 is greater than the anvil feed amount.

[0034] Specifically, the width of the expanding hammer 3 refers to the effective size of its action on the hollow forging blank 1 in the radial or tangential direction when it contacts and applies pressure to the hollow forging blank 1. This width is a key parameter affecting the force-bearing area and flow behavior of the metal material. For example, the working surface of the expanding hammer 3 can be precisely designed and machined to have the expected width size during manufacturing; or, in actual operation, expanding hammers 3 with different working surface widths can be selected for installation and use according to different forging requirements and the size of the hollow forging blank 1.

[0035] The anvil advance refers to the chord length after each rotation of the hollow forging billet 1 by the rotary table 2. This chord length can be adjusted by the rotation angle of the rotary table 2, and it is less than the width of the widening hammer 3, so that any two adjacent pressing surfaces formed by the widening hammer 3 on the surface of the hollow forging billet 1 at least partially overlap. For example, the widening hammer 3 forms a first pressing surface on the surface of the hollow forging billet 1. Then, after the rotary table 2 rotates the hollow forging billet 1 by a certain angle, the widening hammer 3 forms a second pressing surface adjacent to the first pressing surface on the surface of the hollow forging billet 1. The second pressing surface at least partially overlaps with the first pressing surface. Alternatively, it can be understood that in the thickness direction (vertical direction) of the hollow forging billet 1, the downward projection of the second pressing surface and the downward projection of the first pressing surface at least partially overlap. In this process, the rotation angle of the rotary table 2 can be converted into the chord length of the hollow forging billet 1 after rotation, i.e., the anvil advance.

[0036] Throughout the spinning expansion process under the centrosymmetric loading mode, the effective working width of the widening hammer 3 always exceeds the chord length of the hollow forging billet 1 after each rotation. For example, this can be achieved by designing the width of the widening hammer 3 to be 1.2 to 2.5 times the anvil feed amount. The specific multiple can be optimized and determined through experimental verification or numerical simulation based on factors such as the plasticity of the hollow forging billet 1 material, the forging temperature, and the required deformation uniformity.

[0037] Thus, under the over-center symmetric loading mode, when the width of the widened hammer 3 is greater than the anvil feed amount, it ensures that at least two adjacent lower pressing surfaces on the hollow forging billet 1 partially overlap, ensuring the continuity of the upper and lower pressing surfaces of the hollow forging billet 1. This avoids forming defects such as end face warping or wall thickness deviation caused by uneven deformation between any two adjacent lower pressing surfaces, providing an intermediate billet with higher dimensional accuracy and more uniform microstructure for the subsequent eccentric spinning process, thereby improving the overall quality and forming efficiency of the final disc ring forging.

[0038] Optionally, eccentric spinning specifically includes: Adjust the position of the widening hammer 3 so that it is off-center from the center of the hollow forging billet 1; After each downward press of the widening hammer 3, the rotary table 2 rotates by the same angle until the disc-shaped ring forging of the target size is obtained.

[0039] Specifically, adjusting the position of the widening hammer 3 to deviate from the center of the hollow forging blank 1 refers to changing the relative positional relationship between the widening hammer 3 and the hollow forging blank 1, so that its pressing center no longer coincides with the axis of the hollow forging blank 1. This allows for the application of asymmetrical local forging pressure to the hollow forging blank 1 in the later stages of spinning and expanding the hole. This asymmetrical loading mode can specifically guide metal flow to correct local defects that may occur during the early forming process. Specifically, the lateral movement mechanism of the widening hammer 3 can be controlled by a CNC system to make it precisely translate radially, thereby causing its pressing point to deviate from the central axis of the hollow forging blank 1 by a preset distance. Alternatively, the mounting base or fixture of the widening hammer 3 can be adjusted on the worktable to achieve eccentric alignment with the central axis of the hollow forging blank 1.

[0040] Each time the widening hammer 3 is pressed down, the rotary table 2 rotates at a fixed angle, causing the widening hammer 3 to apply an eccentric load at different circumferential positions of the hollow forging blank 1, thereby achieving uniform correction and forming of the entire ring forging. One implementation method is to equip the rotary table 2 with a high-precision encoder and servo motor. After each pressing and lifting of the widening hammer 3, the control system instructs the servo motor to drive the rotary table 2 to precisely rotate by a preset fixed angle, such as 15 degrees, 30 degrees, 45 degrees, or 60 degrees, to ensure uniform coverage in the circumferential direction. Another implementation method is to set up an equal-division positioning mechanism on the rotary table 2. After each pressing down, mechanical limit or sensor triggering causes the rotary table 2 to rotate to the next equal-division position, thereby ensuring the consistency of the rotation angle each time.

[0041] The process continues until the target size of the disc-shaped ring forging is achieved. One approach is to monitor the inner diameter, outer diameter, or wall thickness of the hollow forging blank 1 in real time using an online measurement system (such as a laser rangefinder or vision inspection system). When these parameters reach the preset target values ​​or are within the allowable tolerance range, the system automatically issues a stop command. Another approach is to pre-set the number of eccentric spinning operations or the total processing time based on empirical formulas or finite element simulation results. Once the preset number of operations or time is reached, the target size is considered to have been achieved, and processing stops.

[0042] Thus, by adjusting the position of the widened hammer 3 to deviate from the center of the hollow forging blank 1, the contact geometry between the hammer and the forging blank is changed. This causes the forging pressure to no longer be concentrated on the axis, but rather to generate a specific lateral extrusion force through the eccentric pressing. This asymmetric loading can effectively compensate for the uneven local deformation of the forging blank during the initial hole expansion process. By targeting specific areas with forging pressure, the uniformity of the wall thickness distribution of the disc ring forging can be effectively improved. By coordinating the rotation of the rotary table 2 at the same angle each time, it is ensured that the eccentric forging pressure can uniformly cover the circumference of the hollow forging blank 1. This periodic eccentric loading method allows for coordinated control of the metal's tangential and radial extension, avoiding excessive metal extension along a single direction of least resistance. As a result, while achieving the target dimensions, the geometric accuracy of the forging is significantly improved, reducing the allowance required for subsequent finishing.

[0043] Optionally, adjusting the position of the widening hammer 3 specifically includes translating the widening hammer 3 radially along the hollow forging blank 1.

[0044] Specifically, translating the widening hammer 3 refers to using a mechanical device to translate the widening hammer 3 radially along the hollow forging blank 1 before eccentric spinning, thereby creating a preset deviation between its centerline and the axis of the hollow forging blank 1. There are various ways to achieve this translation of the widening hammer 3. For example, it can be achieved using a precision linear guide system driven by a hydraulic cylinder or servo motor, which can translate the widening hammer 3 radially along the hollow forging blank 1 according to a preset eccentricity command.

[0045] Thus, during the eccentric spinning stage, by radially translating and widening the hammer head 3 along the hollow forging blank 1, its relative position to the axis of the hollow forging blank 1 can be stably changed, thereby achieving controllable eccentric loading. This effectively avoids eccentricity deviation caused by improper adjustment methods, ensuring that the widened hammer head 3 maintains a stable stress state and working posture even after deviating from the center. Therefore, the subsequent eccentric spinning process, which involves rotating the rotary table 2 and repeatedly pressing down, can be carried out on this precise and stable eccentric basis. This effectively suppresses the non-uniformity of metal flow, reduces the risk of forming defects such as uneven wall thickness and end face warping in the disc ring forging, and ultimately ensures the dimensional accuracy and geometric stability of the disc ring forging during the forming stage, improving product quality and material utilization.

[0046] Optionally, the preset threshold is that the inner hole size is close to the inner hole size of the disc-shaped ring forging with a predetermined allowance.

[0047] Specifically, the preset threshold can be determined through theoretical calculations, empirical formulas, or experimental verification, based on factors such as the final size requirements of the target disc-shaped ring forging, material properties, processing equipment accuracy, and subsequent finishing process requirements.

[0048] After the spinning and reaming stage, the inner diameter of the hollow forging blank 1 is very close to the design inner diameter of the final disc ring forging. This degree of closeness is usually defined by a small dimensional difference, for example, it can be set to 95% to 99% of the target inner diameter, or a small fixed value can be subtracted from the target size.

[0049] The predetermined allowance refers to the material thickness reserved for subsequent finishing when the inner hole size of the hollow forging billet 1 reaches a preset threshold and is between its inner hole size and the inner hole size of the final disc-shaped ring forging. Setting this allowance is crucial to ensuring the dimensional accuracy and surface quality of the final product. For example, this predetermined allowance can be determined based on factors such as the process requirements of subsequent finishing processes (e.g., turning, grinding), machine tool accuracy, tool wear, and material removal, and is typically several millimeters to tens of millimeters. By reserving this allowance, dimensional deviations, surface roughness, and localized deformation that may occur during the spinning and reaming process can be effectively compensated for, thereby ensuring the quality of the final product.

[0050] Thus, when the widened hammer 3 spins and expands the hollow forging blank 1, the change in the inner hole size of the hollow forging blank 1 can be monitored in real time. Once the inner hole size reaches the preset threshold, it indicates that it has sufficiently approached the inner hole size of the target disc ring forging and has reserved sufficient finishing allowance. At this point, the spinning and expanding stage can be stopped in time. This effectively avoids the problems of insufficient or excessive expanding caused by the lack of a clear endpoint judgment in traditional methods. That is, insufficient expanding will cause the forging to fail to reach the target size, requiring additional machining passes; while excessive expanding may cause the forging wall thickness to be reduced, material waste, or even internal defects. By accurately setting the preset threshold, this application ensures that the forging can obtain sufficient dimensional expansion during the spinning and expanding stage, while reserving a reasonable material allowance for subsequent finishing, thereby effectively balancing the requirements between forming efficiency and final product accuracy. This not only improves the dimensional control accuracy and forming quality of forgings, reduces the difficulty and material consumption of subsequent finishing, but also helps to reduce the risk of defects such as uneven wall thickness and end face warping caused by non-uniform deformation, thereby improving the overall quality stability of forgings.

[0051] Optionally, the integral forging and spinning method for large-diameter disc ring forgings also includes heating, upsetting and expanding a round bar billet to obtain a hollow forging billet 1.

[0052] Specifically, heating round bar billets aims to effectively reduce the metal's resistance to deformation, improve the material's plasticity, and create favorable conditions for subsequent plastic processing. For example, a gas furnace or resistance furnace can be used to heat the round bar billets. By setting the furnace temperature profile and holding time, the billets can reach the required forging temperature, such as 1100℃-1250℃ for common alloy steels.

[0053] Upsetting is a process of axially compressing heated billets to improve their internal microstructure, eliminate casting defects, and provide a suitable geometry for subsequent reaming. For example, heated round bar billets can be axially upset using upper and lower anvils on a hydraulic or mechanical press to reduce their height and increase their diameter, forming short, thick disc-shaped or drum-shaped billets. Alternatively, multi-directional forging equipment can be used to upset round bar billets in multiple directions to more uniformly compress the material, further refine the grains, and improve the material's density.

[0054] The reaming step transforms the upset solid billet into a hollow forging billet 1 that meets the requirements of the spinning process. This process not only ensures the initial geometric dimensions required for subsequent spinning reaming but also, through pre-deformation treatment, ensures that the metal material possesses good fluidity and uniformity before entering the spinning stage. For example, a punch and die can be used on a hydraulic or mechanical press to punch a hole in the center of the upset billet, forming an initial inner hole. Then, the inner hole diameter is gradually enlarged using a reaming die until the preset size is reached. Alternatively, a mandrel reaming process can be used, where the heated, upset billet is fitted onto a mandrel, and a press is used to axially compress and radially expand the billet, causing it to extend along the mandrel direction and enlarge the inner hole. The resulting hollow forging billet 1 has inner hole dimensions, outer diameter dimensions, and height dimensions that meet the initial geometric requirements of the subsequent spinning reaming process. For example, the inner hole dimensions match the initial widening hammer head 3 dimensions for spinning reaming.

[0055] Thus, by incorporating the pretreatment steps of the round bar billet (heating, upsetting, and reaming) into the overall forming process, source control from raw materials to the hollow forging billet 1 is achieved. This ensures that the hollow forging billet 1 entering the spinning reaming stage has a better initial state, such as a more uniform microstructure, more suitable geometric dimensions, and better plasticity, thereby providing high-quality starting material for subsequent spinning reaming and eccentric spinning under centrosymmetric loading modes. This helps improve the stability of the spinning reaming process, reduce forming defects, and ultimately obtain large-diameter disc-shaped ring forgings with high dimensional accuracy and excellent performance.

[0056] Optionally, the hollow forging 1 is heated before being placed on the rotary table 2.

[0057] Specifically, the purpose of heating the hollow forging billet 1 is to increase its temperature, thereby improving the plasticity of the metal material, reducing its deformation resistance, making it easier for uniform plastic deformation to occur during subsequent spinning and reaming processes, reducing defects, and lowering equipment load. Heating the hollow forging billet 1 can be achieved in various ways. For example, a gas-fired furnace can be used, where high-temperature flames and hot flue gas are generated by burning gas to heat the hollow forging billet 1. This method has high heating efficiency and is suitable for large-scale production.

[0058] Thus, by heating the hollow forging billet 1 at the initial stage of the spinning and expanding process, the plasticity of the metal material can be effectively improved, while its yield strength and deformation resistance can be reduced. When the hollow forging billet 1 is at a higher temperature, its internal grain structure becomes more active, and dislocation movement is more likely to occur. This allows the material to achieve greater plastic deformation with less force when subjected to the pressure of the expanding hammer 3. This fundamentally solves the problems of poor plasticity and high deformation resistance of forging billets at room temperature, which lead to internal cracks, uneven structure, high equipment load, low forming efficiency, and poor final forging quality. After the hollow forging billet 1 has undergone spinning and expanding under a centrally symmetrical loading mode and eccentric spinning, the increased plasticity and reduced deformation resistance allow the metal material to flow more uniformly and smoothly in the radial and tangential directions under the action of the expanding hammer 3. This helps to achieve more precise synergistic control, reduce metal flow inhomogeneity, and effectively avoid forming defects such as uneven local wall thickness and end face warping that are prone to occur in traditional processes. Meanwhile, it reduces energy consumption and mechanical wear during the spinning process, extends equipment lifespan, and significantly improves overall forming efficiency and the quality of the final disc-shaped ring forging. Heating also allows for smaller allowances in subsequent finishing processes, improving material utilization.

[0059] Another embodiment of the present invention provides a spinning and expanding device for integral forging of large-diameter disc-shaped ring forgings, used to realize the aforementioned integral forging and expanding method for large-diameter disc-shaped ring forgings. The spinning and expanding device for integral forging of large-diameter disc-shaped ring forgings includes a widening hammer 3 and a rotary table 2. The rotary table 2 is used to carry the hollow forging blank 1 and drive the hollow forging blank to rotate. The widening hammer 3 is used to press the hollow forging blank 1 through the axis of the hollow forging blank, and is also used to press the hollow forging blank 1 away from the axis.

[0060] Specifically, in the initial stage of hole expansion forming, the widening hammer 3 presses down on the hollow forging billet 1 in an axial manner to achieve a symmetrical loading mode. During this process, the rotary table 2 drives the hollow forging billet 1 to rotate continuously, and the widening hammer 3 applies pressure evenly along the axis, making the radial distribution of metal tend to be uniform, effectively suppressing the flow resistance difference caused by unilateral force, and reducing the phenomenon of metal preferentially extending towards the direction of least resistance. When the inner hole size of the hollow forging billet 1 reaches the preset threshold, the widening hammer 3 switches to an off-axis pressing mode to perform eccentric spinning operation. At this time, by adjusting the eccentric position of the widening hammer 3 and coordinating it with the rotation of the rotary table 2, the wall thickness and end face shape of the hollow forging billet 1 are finely controlled, and local deformation deviations are accurately corrected.

[0061] Thus, the rotary table 2 supports the hollow forging billet 1 and drives its rotation, while the widened hammer 3 presses down on the hollow forging billet 1 through its axis and also presses it off-axis, achieving precise guidance of the metal flow path. Due to the organic combination of symmetrical and eccentric loading modes, tangential and radial deformation are synergistically controlled, significantly improving the non-uniformity of metal flow. Therefore, the need for multiple passes of repeated pressing and finishing in traditional processes is avoided, shortening the forging cycle and improving forming efficiency. Simultaneously, the problems of localized wall thickness unevenness and end-face warping caused by non-uniform deformation are effectively suppressed, reducing the subsequent finishing allowance and improving material utilization, thereby optimizing process economy while solving technical problems.

[0062] Optionally, the widened hammerhead 3 includes an upper part and a lower part along its height direction, the width of the upper part being greater than the width of the lower part, and the lower part being used for forging hollow forging blanks.

[0063] Specifically, the widened hammerhead 3, along its height direction, includes an upper and lower portion, meaning that the cross-sectional shape of the widened hammerhead 3 in the vertical direction presents a stepped or conical structure. The area near the top of the hammerhead (or the end furthest from the forging) has a larger lateral dimension, while the area near the forging surface (or the end in contact with the forging) has a smaller lateral dimension. For example, the upper portion can be rectangular or trapezoidal, and the lower portion can be a narrower rectangular or trapezoidal shape, forming a distinct step; alternatively, the hammerhead can be designed with an overall taper, so that the width gradually decreases from top to bottom, with the upper portion referring to the wider taper area and the lower portion referring to the narrower taper area.

[0064] Thus, by designing the widened hammer head 3 with an upper width greater than the lower width, the lower part can concentrate its force on the hollow forging blank with a smaller contact area during the forging action, thereby increasing the forging pressure per unit area and promoting effective metal flow and filling in local areas. Simultaneously, the larger upper width provides the hammer head with better structural rigidity and stability, acting as support and guide during forging to prevent the hammer head from shifting or tilting under force. This structural design makes metal flow more controllable during forging, effectively improving the wall thickness uniformity of the forging and reducing defects such as end face warping caused by uneven stress. Therefore, while ensuring forming efficiency, it improves the overall quality and dimensional accuracy of the disc ring forging.

[0065] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for integral forging and spinning to expand the hole of a large-diameter disc-shaped ring forging, characterized in that, Includes the following steps: The hollow forging blank (1) is placed on the rotary table (2); The hollow forging blank (1) is spun and expanded using a centrally symmetrical loading mode by using a widened hammer head (3); When the inner hole size of the hollow forging blank (1) under the spinning expansion reaches a preset threshold, the widening hammer (3) performs eccentric spinning on the hollow forging blank (1) until a disc-shaped ring forging of the target size is obtained.

2. The method for integral forging and spinning to expand the hole of a large-diameter disc-shaped ring forging according to claim 1, characterized in that, The over-centrosymmetric loading mode specifically includes: The widening hammer (3) passes through the axis of the hollow forging blank (1); After each press of the widening hammer (3), the rotary table (2) rotates by a preset angle until the inner hole size of the hollow forging blank (1) reaches a preset threshold.

3. The method for integral forging and spinning to expand the hole of a large-diameter disc-shaped ring forging according to claim 2, characterized in that, In the over-central symmetric loading mode, the width of the widened hammer (3) is greater than the amount of anvil feed.

4. The method for integral forging and spinning to expand the hole of a large-diameter disc-shaped ring forging according to claim 1, characterized in that, The eccentric spinning specifically includes: Adjust the position of the widening hammer (3) so that it deviates from the center of the hollow forging blank (1); After each downward press of the widening hammer (3), the rotary table (2) rotates by the same angle until the disc-shaped ring forging of the target size is obtained.

5. The method for integral forging and spinning to expand the hole of a large-diameter disc-shaped ring forging according to claim 4, characterized in that, The adjustment of the position of the widening hammer (3) specifically includes translating the widening hammer (3) radially along the hollow forging blank (1).

6. The method for integral forging and spinning to expand the hole of a large-diameter disc-shaped ring forging according to claim 1, characterized in that, The preset threshold is when the inner hole size is close to the inner hole size of the disc-shaped ring forging and a predetermined allowance is left.

7. The method for integral forging and spinning to expand the hole of a large-diameter disc-shaped ring forging according to claim 1, characterized in that, It also includes obtaining the hollow forging blank (1) by heating, upsetting and expanding the hole of the round bar blank.

8. The method for integral forging and spinning to expand the hole of a large-diameter disc-shaped ring forging according to claim 1, characterized in that, The hollow forging blank (1) is heated before being placed on the rotary table (2).

9. A spinning and expanding device for integral forging of large-diameter disc-shaped ring forgings, used to realize the spinning and expanding method for integral forging of large-diameter disc-shaped ring forgings as described in any one of claims 1-8, characterized in that, It includes a widening hammer (3) and a rotary table (2). The rotary table (2) is used to carry the hollow forging blank (1) and drive the hollow forging blank (1) to rotate. The widening hammer (3) is used to press down on the hollow forging blank (1) through the axis of the hollow forging blank (1) and also to press down on the hollow forging blank (1) away from the axis.

10. The integral forging and spinning reaming device for large-diameter disc-shaped ring forgings according to claim 9, characterized in that, The widening hammer (3) includes an upper part and a lower part along its height direction, the width of the upper part being greater than the width of the lower part, and the lower part being used for forging the hollow forging blank (1).

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