A near-net forming method for a super-large conical cross-section ring forging

Abstract

The present application relates to the technical field of forging forming, and particularly relates to a near-net forming method of an extra-large conical-section ring forging, which comprises the following steps: performing inclined punching on a blank to obtain a conical ring blank; when the preparation of the conical ring blank is determined to be substandard according to a bottom end face wall thickness characteristic value, reducing a preset single-time pressing amount or issuing a warning; placing an inner hole conical surface side of the conical ring blank that meets the standard on a horse frame rod, performing pressing and hole expansion on the conical ring blank by a forging hammer to obtain a conical ring blank after hole expansion; after the conical ring blank after hole expansion is preserved for a preset preservation time, performing ring rolling on the conical ring blank after hole expansion by a ring rolling machine at a preset main roller rotating speed to obtain a conical-section ring forging; when the preparation of the conical-section ring forging is determined to be substandard according to a generatrix curvature characteristic value, determining whether the preparation of the conical-section ring forging meets the standard according to a hardness standard deviation; and cooling and packaging the conical-section ring forging that meets the standard. The present application improves the preparation yield of the extra-large conical-section ring forging.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of forging forming, in particular to a near-net forming method of a super-large conical section ring forging. BACKGROUND

[0002] The super-large conical section ring forging is widely used in high-end equipment fields such as wind power, nuclear power and aerospace due to its excellent force transmission characteristics and spatial adaptability, for example, key components such as launch vehicle cone bottom connecting ring and large wind power flange. This kind of forging usually has characteristics such as large diameter-thickness ratio, long generatrix length and strict conical profile precision, and the forming precision directly affects the subsequent assembly reliability and equipment operation safety.

[0003] At present, the traditional forming process of the super-large conical section ring forging mainly adopts rectangular ring rolling process, which is the most widely used conventional method in the industry. The core process is "rectangular section blank preparation - overall ring rolling expansion - subsequent turning machining forming". However, due to the limitation of its own principle, the rectangular ring rolling process cannot adapt to the asymmetric special section requirement of the super-large conical ring, resulting in problems such as product organization performance degradation, low production efficiency and long process in actual production, which cannot meet the manufacturing demand of near-net forming, high performance and high efficiency of high-end equipment.

[0004] Chinese patent application publication No. CN114309401A discloses a machine body outside free forging near-net forming method of a large-diameter difference replacement ring forging, which comprises the following steps: hot charging of a steel ingot, direct blanking, upsetting forming of a conical blank, preforming of an intermediate blank, forming of an inner hole excess block, preforming of an intermediate blank, forming of an outer circular step, step blank hole expansion forming, furnace return cooling and supplementary heating, machine body outside forming of a large end conical surface, and post-forging heat treatment adopting normalizing and high-temperature tempering heat treatment process.

[0005] It can be seen that the above technical solution does not consider the influence of the circumferential wall thickness of the super-large conical ring blank on the mandrel expansion, and does not consider the influence of the generatrix fluctuation of the super-large conical section ring forging on the forging precision, thereby causing the problem of poor yield of the prepared super-large conical section ring forging. SUMMARY

[0006] Therefore, the present application provides a near-net forming method of a super-large conical section ring forging, which overcomes the problem in the prior art that the influence of the circumferential wall thickness of the super-large conical ring blank on the mandrel expansion is not considered, and the influence of the generatrix fluctuation of the super-large conical section ring forging on the forging precision is not considered, thereby causing the problem of poor yield of the prepared super-large conical section ring forging.

[0007] To achieve the above-mentioned purpose, the present application provides a near-net forming method of a super-large conical section ring forging, comprising:

[0008] obtaining a plurality of circumferential wall thicknesses of the bottom end face of the conical ring blank, and obtaining a bottom end face wall thickness characteristic value of the conical ring blank;

[0009] When it is determined that the preparation of the conical ring blank does not meet the preset standard according to the bottom end face wall thickness characteristic value of the conical ring blank, a preset single pressing amount of subsequent pressing and expanding is reduced based on a difference between the first preset bottom end face wall thickness characteristic value and the bottom end face wall thickness characteristic value.

[0010] The inner hole conical surface side of the conical ring blank is placed on a mandrel rod, and the conical ring blank is pressed and expanded by a corresponding preset single pressing amount by a forging hammer to obtain a conical ring blank after pressing and expanding.

[0011] After the conical ring blank after pressing and expanding is heat preserved for a preset heat preservation time, a ring rolling machine rolls the conical ring blank at a preset main roller speed to obtain a conical cross-section ring forge piece, a plurality of generatrix curvatures of the conical cross-section ring forge piece are collected, and a generatrix curvature characteristic value of the conical cross-section ring forge piece is obtained.

[0012] When it is determined that the preparation of the conical cross-section ring forge piece does not meet the preset standard according to the generatrix curvature characteristic value of the conical cross-section ring forge piece, whether the preparation of the conical cross-section ring forge piece meets the preset standard is determined again according to a hardness standard deviation of the conical cross-section ring forge piece to reduce a preset main roller speed of the next batch.

[0013] The conical cross-section ring forge piece meeting the preset standard is cooled and packaged.

[0014] Further, whether the preparation of the conical ring blank meets the preset standard is determined according to the bottom end face wall thickness characteristic value of the conical ring blank, wherein

[0015] If the bottom end face wall thickness characteristic value is less than the first preset bottom end face wall thickness characteristic value, it is determined that the preparation of the conical ring blank meets the preset standard.

[0016] If the bottom end face wall thickness characteristic value is greater than or equal to the first preset bottom end face wall thickness characteristic value and less than the second preset bottom end face wall thickness characteristic value, it is determined that the preparation of the conical ring blank does not meet the preset standard, and a preset single pressing amount of subsequent pressing and expanding is reduced based on a difference between the first preset bottom end face wall thickness characteristic value and the bottom end face wall thickness characteristic value.

[0017] If the bottom end face wall thickness characteristic value is greater than or equal to the first preset bottom end face wall thickness characteristic value and less than the second preset bottom end face wall thickness characteristic value, it is determined that the preparation of the conical ring blank does not meet the preset standard, and an alarm is issued.

[0018] Further, the process of obtaining the bottom end face wall thickness characteristic value of the conical ring blank comprises:

[0019] A plurality of measuring points are selected at equal intervals along the circumferential direction of the bottom end surface of the conical ring blank, and the wall thickness values of the points are measured respectively;

[0020] An arithmetic mean value of the wall thickness values of the plurality of measuring points and a standard deviation of the wall thickness values of the plurality of measuring points are calculated;

[0021] The ratio of the standard deviation to the arithmetic mean value is recorded as the bottom end surface wall thickness characteristic value of the conical ring blank.

[0022] Further, a plurality of reduction modes of the single-time pressing amount are provided for the reduction of the preset single-time pressing amount, and each reduction mode has a different reduction range of the preset single-time pressing amount.

[0023] Further, whether the preparation of the conical cross-section ring forging meets the preset standard is determined according to the generatrix curvature characteristic value of the conical cross-section ring forging, wherein,

[0024] If the generatrix curvature characteristic value is less than a first preset generatrix curvature characteristic value, it is determined that the preparation of the conical cross-section ring forging meets the preset standard;

[0025] If the generatrix curvature characteristic value is greater than or equal to the first preset generatrix curvature characteristic value and less than a second preset generatrix curvature characteristic value, it is determined that the preparation of the conical cross-section ring forging does not meet the preset standard, and whether the preparation of the conical cross-section ring forging meets the preset standard is determined again according to the hardness standard deviation of the conical cross-section ring forging;

[0026] If the generatrix curvature characteristic value is greater than or equal to the second preset generatrix curvature characteristic value, it is determined that the preparation of the conical cross-section ring forging does not meet the preset standard, and the preset main roller speed of the next batch is reduced according to the difference between the second preset generatrix curvature characteristic value and the generatrix curvature characteristic value.

[0027] Further, the process of obtaining the generatrix curvature characteristic value of the conical cross-section ring forging comprises:

[0028] A plurality of corresponding profile curves of generatrixes are selected at a preset interval along the outer circle of the conical cross-section ring forging in a circumferential direction;

[0029] The curvature values of the plurality of profile curves at the same axial position are obtained, and the curvature standard deviation of the axial position is calculated;

[0030] The maximum curvature standard deviation corresponding to all axial positions is obtained, and is recorded as the generatrix curvature characteristic value of the conical cross-section ring forging.

[0031] Further, whether the preparation of the conical cross-section ring forging meets the preset standard is determined again according to the hardness standard deviation of the conical cross-section ring forging, wherein,

[0032] If the hardness standard deviation is less than the preset hardness standard deviation, it is determined that the preparation of the tapered section ring forging meets the preset standard;

[0033] If the hardness standard deviation is greater than or equal to the preset hardness standard deviation, it is determined that the preparation of the tapered section ring forging does not meet the preset standard, and the preset holding time of the next batch is increased according to the difference between the preset hardness standard deviation and the hardness standard deviation.

[0034] The hardness standard deviation is the standard deviation of the hardness of the tapered section ring forging.

[0035] Further, the increase range of the preset holding time of the next batch is positively correlated with the hardness standard deviation offset value, wherein the hardness standard deviation offset value is the difference between the preset hardness standard deviation and the hardness standard deviation.

[0036] Further, the inclined punching hole includes a first inclined punching hole and a second punching hole performed in sequence, wherein the first inclined punching hole uses an inclined punch with a preset taper angle to form a preliminary tapered inner hole in the blank, and the second punching hole uses a straight punch.

[0037] Further, before the ring rolling machine performs ring rolling at a preset main roller speed, the core shaft of the ring rolling machine is used to drive the expanded tapered ring blank to approach the main roller of the ring rolling machine, and then the tapered roller of the ring rolling machine is brought into contact with the expanded tapered ring blank and the axial position of the tapered roller is kept fixed.

[0038] Compared with the prior art, the beneficial effects of the present application are that by collecting the circumferential wall thickness of the bottom end face of the tapered ring blank immediately after the inclined punching hole and calculating the wall thickness representation value, the initial quality of the blank, especially the punching eccentricity, is quantitatively evaluated, when the wall thickness uniformity is not up to standard but has not been scrapped, the single pressing amount of the subsequent pressing and expanding process can be automatically reduced, thereby improving the geometric accuracy of the ring blank.

[0039] Further, by correlating the mechanical property index (hardness) with the geometric size index (generatrix curvature) for judgment, a multi-dimensional and more practical qualified judgment system is constructed; when the generatrix curvature of the ring piece is slightly over-standard, it is not immediately scrapped, but the hardness uniformity is detected; if the hardness uniformity is good, it means that the internal organization of the product is uniform and meets the use requirements, improving the material utilization and production economy; if the hardness is also not uniform, the heat treatment holding time of the next batch is automatically increased, thereby realizing the precise optimization of the heat treatment process parameters, and ensuring the reliability of the final performance of the product. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 Flowchart of the near-net forming method of the super-large tapered section ring forging of the embodiment of the present application;

[0041] Figure 2 Flow chart for determining whether the preparation of the conical ring blank meets the preset standard for the embodiment of the present application;

[0042] Figure 3 Flow chart for determining whether the preparation of the conical ring blank meets the preset standard according to the characteristic value of the generatrix curvature of the conical section ring forging for the embodiment of the present application;

[0043] Figure 4 Flow chart for determining whether the preparation of the conical section ring forging meets the preset standard according to the hardness standard deviation for the embodiment of the present application. DETAILED DESCRIPTION

[0044] In order to make the objects and advantages of the present application clearer, the present application will be further described below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0045] The preferred embodiments of the present application will be described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present application and not to limit the protection scope of the present application.

[0046] It should be pointed out that the data in the present embodiment are obtained by comprehensive analysis and evaluation of the historical detection data and the corresponding historical detection results of the present application in the past three months before the present detection. Those skilled in the art can understand that the determination method of the present application for a single parameter can be to select the value with the highest proportion as the preset standard parameter according to the data distribution, to use weighted summation to obtain the value as the preset standard parameter, to substitute each historical data into a specific formula and to obtain the value by using the formula as the preset standard parameter, or other selection methods, as long as the present application can clearly define different specific situations in the single determination process by using the obtained value.

[0047] Please refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 , which are respectively flow charts of the near-net forming method of the extra-large conical section ring forging, the flow chart for determining whether the preparation of the conical ring blank meets the preset standard, the flow chart for determining whether the preparation of the conical section ring forging meets the preset standard, and the flow chart for determining whether the preparation of the conical section ring forging meets the preset standard for the embodiment of the present application.

[0048] The embodiment of the present application provides a near-net forming method of an extra-large conical section ring forging, which comprises:

[0049] Step S1, send the blank into the heating furnace, and raise the temperature from 800℃ to 1250℃ at a rate of 10℃ / min;

[0050] Step S2, the oil press adopts a φ990mm*φ550mm (taper angle 45°) inclined punch to punch the blank, to obtain a first punching semi-finished product with a size of φ1480mm*T300mm, and a φ550mm straight punch is used to punch the first punching semi-finished product for the second time, to obtain a tapered ring blank, and the circumferential wall thickness of the bottom end face of the tapered ring blank is collected to obtain the bottom end face wall thickness characteristic value of the tapered ring blank;

[0051] Step S3, when the preparation of the tapered ring blank does not meet the preset standard according to the bottom end face wall thickness characteristic value of the tapered ring blank, the preset single pressing amount of the subsequent pressing and expanding is reduced or an alarm is issued;

[0052] Step S4, after the tapered ring blank meeting the preset standard is reheated at 1250℃, the inner hole tapered surface side of the tapered ring blank is placed on a mandrel rod, and the tapered ring blank is pressed and expanded by a preset single pressing amount of 50mm by a forging hammer, to obtain an expanded tapered ring blank, wherein the tapered ring blank is processed by 10mm flattening every time a circumferential rotation is completed;

[0053] Step S5, after the expanded tapered ring blank is preserved for a preset preservation time of 24min, a ring rolling machine is used to roll the ring at a preset main roller speed of 700RPM, to obtain a tapered cross-section ring forging, and the curvatures of a plurality of generatrices of the tapered cross-section ring forging are collected to obtain the generatrix curvature characteristic value of the tapered cross-section ring forging;

[0054] Step S6, when the preparation of the tapered cross-section ring forging does not meet the preset standard according to the generatrix curvature characteristic value of the tapered cross-section ring forging, whether the preparation of the tapered cross-section ring forging meets the preset standard is determined again according to the hardness standard deviation of the tapered cross-section ring forging, or the preset main roller speed of the next batch is reduced;

[0055] Step S7, the tapered cross-section ring forging meeting the preset standard is cooled and packaged.

[0056] It should be noted that the data in the present embodiment are all results obtained through preliminary experiments before the present detection by the method of the present application, and each preset value can be adjusted according to the specific use, as long as the method of the present application can determine different specific conditions in the single determination process through the obtained values. The preset values set in the present embodiment are all obtained according to preliminary experiments, and each correction coefficient is also selected through experimental verification.

[0057] Specifically, before the ring rolling mill rolls the ring at a preset main roller speed, the mandrel of the ring rolling mill drives the expanded conical ring blank close to the main roller of the ring rolling mill. Then, the conical roller of the ring rolling mill contacts the expanded conical ring blank and keeps the axial position of the conical roller fixed. The main roller speed is 700 RPM, and the mandrel feed adopts segmented ring rolling. In the first stage, the mandrel-main roller spacing is 463.5-440mm, and the feed is 0.4mm / s. In the second stage, the mandrel-main roller spacing is 440mm-343.5mm, and the feed is 2mm / s. In the third stage, the mandrel-main roller spacing is 343.5mm-276.5mm, and the feed is 1.4mm / s. In the fourth stage, the mandrel-main roller spacing is 276.5mm-130mm, and the feed is 0.8mm. In the fifth stage, the mandrel-main roller spacing is 130mm-124.5mm, and the feed is 0.4mm.

[0058] Specifically, the fabrication of the conical ring blank is determined based on the characterization value of the bottom end wall thickness, indicating whether the fabrication meets the preset standard.

[0059] If the bottom end wall thickness characterization value is less than the first preset bottom end wall thickness characterization value of 0.005, then the preparation of the conical ring blank is determined to meet the preset standard;

[0060] If the bottom end face wall thickness characterization value is greater than or equal to the first preset bottom end face wall thickness characterization value and less than the second preset bottom end face wall thickness characterization value by 0.01, then it is determined that the preparation of the conical ring blank does not meet the preset standard, and the preset single pressing amount of the subsequent pressing hole expansion is reduced according to the difference between the first preset bottom end face wall thickness characterization value and the bottom end face wall thickness characterization value.

[0061] If the bottom end face wall thickness characterization value is greater than or equal to the first preset bottom end face wall thickness characterization value and less than the second preset bottom end face wall thickness characterization value, then it is determined that the preparation of the conical ring blank does not meet the preset standard, and an alarm is issued.

[0062] Specifically, the first preset bottom end face wall thickness characterization value ranges from [0.003, 0.008], and the second preset bottom end face wall thickness characterization value ranges from [0.008, 0.015]. Preferably, the first preset bottom end face wall thickness characterization value is 0.005, and the second preset bottom end face wall thickness characterization value is 0.01.

[0063] Specifically, the bottom end face wall thickness characterization value reflects the circumferential wall thickness uniformity of the billet. The smaller the ratio, the higher the uniformity. If the wall thickness characterization value is less than the first preset bottom end face wall thickness characterization value, it indicates that the billet wall thickness fluctuation is minimal (excellent uniformity), which meets the high requirements of near-net-shape forming for the geometric accuracy of the billet. If the wall thickness characterization value is greater than or equal to the second preset bottom end face wall thickness characterization value, it indicates that the wall thickness fluctuation is significant (poor uniformity), which is prone to stress concentration, cracks, or poor ellipticity during hole expansion.

[0064] Specifically, the process of obtaining the characterization value of the bottom end wall thickness of the conical ring blank includes:

[0065] Several measuring points are selected at equal intervals along the circumference of the bottom end face of the conical ring blank, and the wall thickness value of each point is measured respectively.

[0066] Calculate the arithmetic mean of the wall thickness values ​​at several measurement points and the standard deviation of the wall thickness values ​​at several measurement points;

[0067] The ratio of the standard deviation to the arithmetic mean is denoted as the characterization value of the bottom end wall thickness of the conical ring blank.

[0068] Specifically, several methods for reducing the preset single pressure amount are provided, among which,

[0069] If the wall thickness deviation value is less than the first preset wall thickness deviation value, the preset single pressing amount is reduced to the corresponding value using the first adjustment coefficient of 0.96.

[0070] If the wall thickness deviation value is greater than or equal to the first preset wall thickness deviation value and less than the second preset wall thickness deviation value, then the preset single downward pressure amount is reduced to the corresponding value using the second adjustment coefficient of 0.94.

[0071] If the wall thickness deviation value is greater than or equal to the second preset wall thickness deviation value, then the preset single downward pressure amount is reduced to the corresponding value using the third adjustment coefficient of 0.92;

[0072] The wall thickness deviation value is the difference between the first preset bottom end wall thickness characterization value and the bottom end wall thickness characterization value.

[0073] Specifically, the fabrication of the tapered cross-section ring forging is determined to meet a preset standard based on the generatrix curvature characterization value of the forging.

[0074] If the curvature value of the busbar is less than the first preset curvature value of the busbar by 0.0003 mm -1 If the preparation of the tapered cross-section ring forging is deemed to meet the preset standard, then the preparation of the ring forging is deemed to meet the preset standard.

[0075] If the busbar curvature characterization value is greater than or equal to the first preset busbar curvature characterization value and less than the second preset busbar curvature characterization value by 0.0006 mm... -1 If the preparation of the tapered cross-section ring forging does not meet the preset standard, the preparation of the tapered cross-section ring forging will be determined a second time based on the hardness standard deviation of the tapered cross-section ring forging.

[0076] If the curvature characterization value of the busbar is greater than or equal to the second preset busbar curvature characterization value, it is determined that the preparation of the tapered cross-section ring forging does not meet the preset standard, and the preset main roll speed of the next batch is reduced according to the difference between the second preset busbar curvature characterization value and the busbar curvature characterization value.

[0077] Specifically, the range of the first preset busbar curvature characterization value is [0.00025mm]. -1 , 0.000550mm -1 The first preset busbar curvature characterization value ranges from [0.00055mm]. -1 0.00085mm -1 Preferably, the first preset busbar curvature characterization value is 0.0003 mm. -1 The second preset busbar curvature characterization value is 0.0006 mm. -1 .

[0078] Specifically, the curvature characterization value reflects the accuracy of the conical ring profile. For key structural components such as extra-large wind turbine towers, there are extremely high requirements for roundness and straightness of the busbar. The curvature characterization value essentially quantifies the non-straightness of the busbar.

[0079] Specifically, the process of obtaining the generatrix curvature characterization value of the tapered cross-section ring forging includes:

[0080] Along the outer circle of the tapered cross-section ring forging, a number of corresponding contour curves of generatrices are uniformly selected at preset intervals in the circumferential direction.

[0081] Obtain the curvature values ​​of several contour curves at the same axial position, and calculate the standard deviation of curvature at that axial position;

[0082] Obtain the largest standard deviation of curvature corresponding to all axial positions, and denot it as the generatrix curvature characterization value of the tapered cross-section ring forging.

[0083] Specifically, the preparation of the tapered cross-section ring forging is determined twice based on the standard deviation of its hardness, to determine whether the forging meets the preset standard.

[0084] If the hardness standard deviation is less than the preset hardness standard deviation of 18HB, then the preparation of the tapered cross-section ring forging is determined to meet the preset standard.

[0085] If the hardness standard deviation is greater than or equal to the preset hardness standard deviation, it is determined that the preparation of the tapered cross-section ring forging does not meet the preset standard, and the preset heat preservation time of the next batch is increased according to the difference between the preset hardness standard deviation and the hardness standard deviation.

[0086] The hardness standard deviation is the standard deviation of several hardnesses of the tapered cross-section ring forging.

[0087] In this embodiment, the preset hardness standard deviation is 18HB. The 50 alternating load tests of the wind turbine main shaft bearing show that when the hardness standard deviation is less than 18HB, the fatigue life deviation of each part of the ring blank is less than 10%, and there is no risk of local early failure. However, the above value is not limited to this, and those skilled in the art can also adjust the value according to actual needs.

[0088] Specifically, the increase in the preset heat preservation time for the next batch is positively correlated with the hardness standard deviation offset value. The positive correlation can be linear or non-linear. The linear slope of the linear positive correlation is not specifically limited. It can be understood that the larger the hardness standard deviation offset value, the greater the increase in the preset heat preservation time. The hardness standard deviation offset value is the difference between the preset hardness standard deviation and the hardness standard deviation.

[0089] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A near-net-shape forming method for an extra-large conical cross-section ring forging, characterized in that, include: The billet is punched at an angle to obtain a conical ring billet. Several circumferential wall thicknesses of the bottom end face of the conical ring billet are collected, and the characterization value of the bottom end face wall thickness of the conical ring billet is obtained. The quality of the conical ring blank's preparation is determined based on the characterization value of the bottom end wall thickness. This characterization determines whether the preparation of the conical ring blank meets the preset standard. If the bottom end wall thickness characterization value is less than the first preset bottom end wall thickness characterization value, then the preparation of the conical ring blank is determined to meet the preset standard; If the bottom end face wall thickness characterization value is greater than or equal to the first preset bottom end face wall thickness characterization value and less than the second preset bottom end face wall thickness characterization value, then it is determined that the preparation of the conical ring blank does not meet the preset standard, and the preset single pressing amount of the subsequent pressing hole expansion is reduced according to the difference between the first preset bottom end face wall thickness characterization value and the bottom end face wall thickness characterization value. If the bottom end wall thickness characterization value is greater than or equal to the second preset bottom end wall thickness characterization value, it is determined that the preparation of the conical ring blank does not meet the preset standard, and an alarm is issued. The inner conical surface of the conical ring blank is placed on a frame bar, and the conical ring blank is pressed down with a forging hammer to expand the hole with a corresponding preset single pressing amount to obtain the expanded conical ring blank. After the expanded conical ring blank is kept at a preset temperature for a preset time, the ring rolling mill rolls the ring at a preset main roller speed to obtain a conical cross-section ring forging. The curvature of several generatrices of the conical cross-section ring forging is collected, and the generatrice curvature characterization value of the conical cross-section ring forging is obtained. The fabrication of the tapered cross-section ring forging is determined based on the generatrix curvature characterization value. This determines whether the fabrication meets the preset standards. If the curvature characterization value of the generatrix is ​​less than the first preset curvature characterization value of the generatrix, then the preparation of the tapered cross-section ring forging is determined to meet the preset standard. If the curvature characterization value of the busbar is greater than or equal to the first preset busbar curvature characterization value and less than the second preset busbar curvature characterization value, it is determined that the preparation of the tapered cross-section ring forging does not meet the preset standard, and the preparation of the tapered cross-section ring forging is determined a second time based on the hardness standard deviation of the tapered cross-section ring forging. The preparation of the tapered cross-section ring forging is determined twice based on the standard deviation of its hardness to determine whether it meets the preset standard. If the hardness standard deviation is less than the preset hardness standard deviation, then the preparation of the tapered cross-section ring forging is determined to meet the preset standard. If the hardness standard deviation is greater than or equal to the preset hardness standard deviation, it is determined that the preparation of the tapered cross-section ring forging does not meet the preset standard, and the preset heat preservation time of the next batch is increased according to the difference between the preset hardness standard deviation and the hardness standard deviation. The hardness standard deviation is the standard deviation of several hardnesses of the tapered cross-section ring forging; If the curvature characterization value of the busbar is greater than or equal to the second preset busbar curvature characterization value, it is determined that the preparation of the tapered cross-section ring forging does not meet the preset standard, and the preset main roll speed of the next batch is reduced according to the difference between the second preset busbar curvature characterization value and the busbar curvature characterization value. The tapered cross-section ring forgings that meet the preset standards are cooled and packaged.

2. The near-net-shape forming method for extra-large conical cross-section ring forgings according to claim 1, characterized in that, The process of obtaining the characterization value of the bottom end face wall thickness of the conical ring blank includes: Several measuring points are selected at equal intervals along the circumference of the bottom end face of the conical ring blank, and the wall thickness value of each point is measured respectively. Calculate the arithmetic mean of the wall thickness values ​​at several measurement points and the standard deviation of the wall thickness values ​​at several measurement points; The ratio of the standard deviation to the arithmetic mean is denoted as the characterization value of the bottom end wall thickness of the conical ring blank.

3. The near-net-shape forming method for extra-large conical cross-section ring forgings according to claim 2, characterized in that, Several methods for reducing the preset single pressure amount are provided, and each method reduces the preset single pressure amount by a different amount.

4. The near-net-shape forming method for extra-large conical cross-section ring forgings according to claim 3, characterized in that, The process of obtaining the generatrix curvature characterization value of the tapered cross-section ring forging includes: Along the outer circle of the tapered cross-section ring forging, a number of corresponding contour curves of generatrices are uniformly selected at preset intervals in the circumferential direction. Obtain the curvature values ​​of several contour curves at the same axial position, and calculate the standard deviation of curvature at that axial position; Obtain the largest standard deviation of curvature corresponding to all axial positions, and denot it as the generatrix curvature characterization value of the tapered cross-section ring forging.

5. The near-net-shape forming method for extra-large conical cross-section ring forgings according to claim 4, characterized in that, The increase in the preset heat preservation time for the next batch is positively correlated with the hardness standard deviation offset value, wherein the hardness standard deviation offset value is the difference between the preset hardness standard deviation and the hardness standard deviation.

6. The near-net-shape forming method for extra-large tapered cross-section ring forgings according to claim 1, characterized in that, The oblique punching includes a first oblique punching and a second punching performed sequentially. The first oblique punching uses an oblique punch with a preset cone angle to form a preliminary conical inner hole in the blank. The second punching uses a straight punch.

7. The near-net-shape forming method for extra-large tapered cross-section ring forgings according to claim 1, characterized in that, Before the ring rolling machine rolls the ring at a preset main roller speed, the mandrel of the ring rolling machine is used to drive the expanded conical ring blank close to the main roller of the ring rolling machine. Then, the conical roller of the ring rolling machine is brought into contact with the expanded conical ring blank and the axial position of the conical roller is kept fixed.

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