A shaping tool and shaping method for super-large cylindrical forgings

Abstract

The present invention relates to a shaping tool and shaping method for super-large cylindrical forgings, which belongs to the technical field of super-large cylindrical forging manufacturing, and solves the technical problems that the existing shaping methods cannot accurately shape and are not suitable for shaping super-large cylindrical forgings with large deformation. The shaping tool of the present invention is arranged in a heat treatment furnace; the shaping tool includes a forging support unit and a forging shaping unit; the forging support unit includes an annular support steel plate, a plurality of annular support washers and a plurality of radial support washers, and the annular support washers are evenly distributed along the circumference of the annular support steel plate; the radial support washers are evenly distributed along the short axis direction of the super-large cylindrical forging; the forging shaping unit is used to shape the super-large cylindrical forging. The present invention uses a large-tonnage hydraulic jack as a force source to apply force to the short axis direction of the inner hole of the super-large cylindrical forging, so that the super-large cylindrical forging undergoes elastic deformation in the radial direction, the short axis is elongated, and the long axis is contracted, thereby achieving the purpose of accurate shaping.

Description

Technical Field

[0001] The present invention relates to the technical field of manufacturing super-large cylindrical forgings, and in particular to a shaping tool and a shaping method for super-large cylindrical forgings. Background Art

[0002] Oversized cylindrical forgings are often used in pressure vessel equipment. As pressure vessel equipment grows in size, the required cylindrical forgings also increase in size. To achieve the performance requirements required by these equipment, oversized cylindrical forgings require heat treatment. During heat treatment, due to expansion during heating, uneven cooling, or insufficient leveling and solidification during furnace loading, forgings can deform, most commonly resulting in noticeable slenderness or short-shortness. For oversized cylindrical forgings, the larger the diameter, the greater the tendency to deform during heat treatment.

[0003] If the deformation exceeds the machining allowance of the forging after deformation, it will not meet the subsequent finishing dimensions and requires reshaping. For cylindrical forgings with smaller diameters, reshaping is usually done using a press. However, for very large cylindrical forgings with a diameter exceeding 7m, existing presses cannot be used for reshaping due to travel limitations.

[0004] Currently, there is limited research on the shape correction of very large cylindrical forgings. Some studies utilize the principle of thermal expansion and contraction, placing a shaping fixture inside the forging while it is hot. Upon cooling, the forging contracts, and the shaping fixture counteracts the contraction of the minor axis, thereby reducing the forging's elliptical mass. This method cannot achieve precise shape correction, and because it cannot increase the minor axis diameter, it cannot achieve the desired shape correction for forgings with significant deformation. Summary of the Invention

[0005] In view of the above analysis, the embodiments of the present invention aim to provide a shaping tool and shaping method for ultra-large cylindrical forgings, so as to solve the technical problems that the existing shaping methods cannot accurately shape and cannot shape ultra-large cylindrical forgings with large deformations.

[0006] The purpose of the present invention is mainly achieved through the following technical solutions:

[0007] In one aspect, the present invention provides a shaping tool for an oversized cylindrical forging, the shaping tool being arranged in a heat treatment furnace; the shaping tool comprising a forging support unit and a forging shaping unit; the forging support unit being arranged below the oversized cylindrical forging;

[0008] The forging support unit includes an annular support steel plate, multiple annular support pads and multiple radial support pads. The annular support pads are evenly distributed along the circumference of the annular support steel plate; the radial support pads are evenly distributed along the short axis direction of the super-large cylindrical forging;

[0009] The forging shape correction unit is located above the radial support pad in the super-large cylindrical forging; the forging shape correction unit is used to correct the super-large cylindrical forging.

[0010] In one possible design, the shaping jig for oversized cylindrical forgings also includes a level;

[0011] The level is installed on the radial support pad at the center of the heat treatment furnace; the level is used to check whether the heights of the circumferential support pads are the same;

[0012] The forging shaping unit includes a first shaping washer and a second shaping washer; the first shaping washer and the second shaping washer are both in the shape of a cuboid;

[0013] The first end of the first shaping pad and the first end of the second shaping pad are both adjacent to the inner surface of the oversized cylindrical forging; the second end of the first shaping pad is adjacent to the second end of the second shaping pad; the end face of the second end of the first shaping pad is provided with an upper supporting steel plate and a lower supporting steel plate parallel to each other, and a hydraulic jack is provided in the accommodating space formed by the upper supporting steel plate and the lower supporting steel plate.

[0014] In a possible design, arc-shaped thin steel plates are provided on the end surfaces of the first end of the first shaping washer and the first end of the second shaping washer, and the arc-shaped thin steel plates are used to prevent indentations from occurring in the inner hole of the forging during the shaping process.

[0015] In one possible design, the shaping unit further includes a plurality of support blocks and connecting blocks. After the oversized cylindrical forging is shaped, connecting blocks are welded between the second shaping pad and the upper support steel plate, and between the second shaping pad and the lower support steel plate. The support blocks are used to replace the hydraulic jacks for support.

[0016] Connecting blocks are used to fix the dimensions of oversized forgings after they have been shaped.

[0017] In one possible design, the hydraulic jack is a large-tonnage hydraulic jack of 500 tons.

[0018] In a possible design, the diameter of the super-large cylindrical forging ranges from 7.0 to 11.5 m; the weight of the super-large cylindrical forging is greater than 100 tons.

[0019] On the other hand, the present invention also provides a method for correcting the shape of an oversized cylindrical forging, using the above-mentioned correction tool for correcting the shape of an oversized cylindrical forging, comprising the following steps:

[0020] Step 1: Before loading into the furnace, measure the size of the super-large cylindrical forging, determine the major axis and minor axis of the super-large cylindrical forging, and mark the major axis and minor axis orientations on the inner and outer surfaces of the super-large cylindrical forging;

[0021] Step 2: When loading the furnace, place an annular support steel plate on the heat treatment furnace, evenly distribute annular support shims on the annular support steel plate, and place radial support shims in the short axis direction of the oversized cylindrical forging; place a spirit level on the radial support shims at the center of the furnace bottom of the heat treatment furnace;

[0022] Step 3: Use a level to check the height of all the annular support washers. If the heights of the annular support washers are consistent, remove the level and place the oversized cylindrical forging on the annular support washers.

[0023] Step 4: Use the shape correction unit to correct the shape of the super-large cylindrical forging;

[0024] Step 5: Welding connecting blocks between the upper support steel plate and the second shaping pad, and between the lower support steel plate and the second shaping pad;

[0025] Step 6: Remove the hydraulic jack and place a support block at the original hydraulic jack position;

[0026] Step 7: Perform stress relief heat treatment and remove the shape correction tooling after heat treatment.

[0027] Furthermore, in step 4, the first shaping shim and the second shaping shim are placed on the radial support shim; a hydraulic jack is placed in the accommodation space formed by the upper support steel plate and the lower support steel plate of the first shaping shim, and the shaping process is carried out.

[0028] Furthermore, in step 4, the shaping process is as follows: using a hydraulic jack to apply pressure so that the first ends of the first shaping shim and the second shaping shim are in contact with the cylinder wall of the oversized cylindrical forging; gradually increasing the pressure, maintaining the pressure for 10±1 minutes each time, and then measuring the long axis size of the oversized cylindrical forging until the expected deformation is reached.

[0029] Furthermore, in step 4, the hydraulic jack is pressurized to 10±0.5 MPa and maintained for 10±1 min to detect the deformation of the major and minor axes of the forging; the hydraulic jack is pressurized to 20±0.5 MPa and maintained for 10±1 min to detect the deformation of the major and minor axes of the forging;

[0030] Use the hydraulic jack to increase the pressure to 30±0.5MPa and maintain the pressure for 10±1min to detect the deformation of the major and minor axes of the forging; gradually increase the pressure and maintain the pressure for 10±1min; after the hydraulic jack increases the pressure to 60±0.5MPa and reaches the stroke required for the expected deformation, stop pressurizing and maintain the pressure for 10±1min to detect the actual deformation of the forging.

[0031] Furthermore, in step 7, the stress relief heat treatment process is as follows: the oversized cylindrical forging is kept at a temperature of 250-300°C for 4-4.5 hours; then the temperature of the heat treatment furnace is increased to 500-540°C at a rate of ≤55°C / h and kept at that temperature for 2-2.5 hours; then the temperature of the heat treatment furnace is increased to 550-600°C at a rate of ≤55°C / h and kept at that temperature for 9-9.5 hours; finally, the temperature of the heat treatment furnace is decreased to 350°C at a rate of ≤55°C / h and the forging is taken out of the furnace and air-cooled.

[0032] Furthermore, in step 3, if the heights of the annular support washers are inconsistent, find the highest annular support washers as a benchmark, record the heights of the other annular support washers that need to be filled, and fill the heights with thin steel plates.

[0033] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0034] (1) The present invention utilizes a large-tonnage hydraulic jack as a force source to apply force to the inner bore of an oversized cylindrical forging in the direction of the minor axis, causing the cylindrical forging to undergo elastic deformation in the radial direction, with the minor axis extending and the major axis contracting, thereby achieving the purpose of shape correction. When the deformation reaches a predetermined target value, a connecting block is welded in the direction of the jack's force to maintain the deformation. The jack is then removed, a support block is added, and finally the oversized cylindrical forging and the shape correction tooling are placed in a furnace for stress relief heat treatment, causing the cylindrical forging to achieve permanent deformation, completing the shape correction process.

[0035] (2) After being calibrated by the precise calibration method for the ultra-large cylindrical forgings provided by the present invention, the size of the ultra-large cylindrical forgings meets the size of the delivery drawing, and there is a processing allowance of about 5 mm on one side, achieving an ideal calibration effect.

[0036] (3) The end faces of the first end of the first shaping pad and the first end of the second shaping pad in the present invention are both provided with arc-shaped thin steel plates, and the shape of the arc-shaped thin steel plates fits the shape of the furnace wall of the heat treatment furnace, thereby preventing the inner hole of the oversized cylindrical forging from having indentations during the shaping process.

[0037] In the present invention, the above-mentioned technical solutions can be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages will become apparent from the description or be understood through practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the embodiments of the description and the contents particularly pointed out in the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like parts throughout the drawings.

[0039] Figure 1 This is a schematic diagram of the shape correction tool structure of the present invention (taking a circular furnace bottom as an example);

[0040] Figure 2 It is a schematic diagram of the shape correction unit of the present invention;

[0041] Figure 3 yes Figure 2 AA direction view;

[0042] Figure 4 It is a schematic diagram of an oversized cylindrical forging;

[0043] Figure 5 This is a top view of the oversized cylindrical forging after marking four angles;

[0044] Figure 6 It is a schematic diagram of the stress relief heat treatment process;

[0045] Figure 7 This is a schematic diagram of the support block structure added when correcting the shape of an oversized cylindrical forging with a variable diameter.

[0046] Reference numerals:

[0047] 1- Annular support shim; 2- Radial support shim; 3- Annular support steel plate; 4- Extra large cylindrical forging profile; 5- Short shaft; 6- Bottom of heat treatment furnace; 7- Level; 8- First shaping shim; 9- Second shaping shim; 10- Upper support steel plate; 11- Lower support steel plate; 12- Hydraulic jack; 13- First section; 14- Second section; 15- Third section; 16- First support block; 17- Second support block; 18- Third support block. DETAILED DESCRIPTION

[0048] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, and are not used to limit the scope of the present invention.

[0049] Example 1

[0050] This embodiment 1 provides a shaping tool for an extra-large cylindrical forging, for example, the diameter range of the extra-large cylindrical forging is 7.0 to 11.5 m; the weight of the extra-large cylindrical forging is greater than 100 tons; the shaping tool includes a forging support unit and a forging shaping unit; the forging support unit includes an annular support steel plate 3, multiple annular support washers 1 and multiple radial support washers 2, the annular support washers 1 are evenly distributed along the circumference of the annular support steel plate 3; the radial support washers 2 are evenly distributed along the short axis 5 of the extra-large cylindrical forging; the forging shaping unit is used to shape the extra-large cylindrical forging.

[0051] Specifically, as the present invention Figures 1 to 6 As shown, the shaping tooling of the super-large cylindrical forging of the present invention includes a forging support unit and a forging shaping unit; a heat treatment furnace, wherein the forging support unit includes an annular support steel plate 3, a plurality of annular support pads 1 and a plurality of radial support pads 2, the annular support pads 1 are arranged on the annular support steel plate 3, and are evenly placed along the circumference of the annular support steel plate 3, and the radial support pads 2 are evenly distributed along the short axis 5 of the super-large cylindrical forging. The super-large cylindrical forging is lifted by a crane to be stably placed on the annular support pad 1, and the supporting parts of the forging are flattened and padded. After placement, the super-large cylindrical forging profile 4 is as shown Figure 1 As shown, at this time, the forging shaping unit is placed on the radial support pad 2, and the shaping process is performed on the super-large cylindrical forging.

[0052] In the prior art, it is impossible to use existing presses to calibrate the shape of super-large cylindrical forgings with a diameter exceeding 7m. However, there are few studies on the calibration of super-large cylindrical forgings. Existing studies use the principle of thermal expansion and contraction. When the forging is hot, a shaping tool is placed inside the forging. After cooling, the forging shrinks, and the shaping tool resists the contraction of the minor axis 5, thereby reducing the elliptical amount of the forging. This method cannot achieve accurate calibration, and since the diameter of the minor axis 5 cannot be increased, the calibration purpose cannot be achieved by this method for forgings with large deformation. Compared with the prior art, the present invention uses a calibration unit to apply force to the direction of the minor axis 5 of the inner hole of the cylindrical forging, causing the cylindrical forging to undergo elastic deformation in the radial direction, the minor axis 5 to elongate, and the major axis to shrink, so as to achieve the calibration purpose. When the deformation reaches the predetermined target value, a connecting block is welded in the force direction of the calibration unit to maintain the deformation. Then the jack is removed and a support block is added. Finally, the cylindrical forging and the calibration tool are put into the furnace as a whole for stress relief heat treatment, so that the cylindrical forging reaches permanent deformation and the calibration is completed.

[0053] In order to more accurately correct the shape of the oversized cylindrical forgings, the oversized cylindrical forging tooling of the present invention also includes a spirit level 7, which is used to detect whether the heights of each annular support washer 1 are the same; the spirit level 7 is arranged on the radial support washer 2 at the center of the bottom 6 of the heat treatment furnace; the correction unit includes a first correction washer 8 and a second correction washer 9; the first correction washer 8 and the second correction washer 9 are both rectangular; the first end of the first correction washer 8 and the first end of the second correction washer 9 are both adjacent to the inner surface of the short axis 5 of the oversized cylindrical forging, and the second end of the first correction washer 8 is adjacent to the second end of the second correction washer 9; the end face of the second end of the first correction washer 8 is provided with an upper support steel plate 10 and a lower support steel plate 11 parallel to each other, and a hydraulic jack 12 is provided in the accommodating space formed by the upper support steel plate 10 and the lower support steel plate 11.

[0054] Specifically, the radial support washer 2 includes a first radial support washer, a second radial support washer and a third radial support washer, wherein the second radial support washer is located at the center of the bottom of the heat treatment furnace. When it is necessary to detect whether the heights of the annular support washer 1 are consistent, the spirit level is placed on the second radial support washer. If the heights of the annular support washer 1 are the same, the level detection unit is removed. If they are inconsistent, find the highest annular support washer 1, use it as a reference, record the heights of the other annular support washer 1 that need to be filled, and use thin steel plates to fill the heights into the same height plane. The spirit level 7 is removed after use; the correction unit includes a first correction washer 8 and a second correction washer 9. The first The shaping shim 8 and the second shaping shim 9 are arranged on the radial support shim 2 along the direction of the short axis 5 of the oversized cylindrical forging. The first end of the first shaping shim 8 and the first end of the second shaping shim 9 are adjacent to the inner surface of the short axis 5 of the oversized cylindrical forging. The end face of the second end of the first shaping shim 8 is provided with an upper support steel plate 10 and a lower support steel plate 11 parallel to each other. The accommodating space formed by the upper support steel plate 10 and the lower support steel plate 11 is used to place the hydraulic jack 12. The hydraulic jack 12 is used as a force source to apply force in the direction of the inner hole short axis 5 of the oversized cylindrical forging, so that the oversized cylindrical forging undergoes elastic deformation in the radial direction, the short axis 5 is elongated, and the long axis is contracted, so as to achieve the purpose of shaping.

[0055] It should be noted that the first and second shaping washers 8, 9 of the present application are rectangular parallelepiped, and the annular support washers 1 and radial support washers 2 can be rectangular parallelepiped, cylindrical, or other shapes. The first and second shaping washers 8, 9, annular support washers 1, and radial support washers 2 are all provided with lifting lugs on their sides to facilitate lifting and moving the support washers and shaping washers.

[0056] It should be noted that the shape of the above-mentioned lifting ear is a "7" shape. Setting the shape of the lifting ear to a "7" shape can ensure that the chain firmly hooks the lifting ear, making it convenient to lift the first shaping shim 8, the second shaping shim 9, the annular support shim 1 and the radial support shim 2.

[0057] In order to prevent indentations from occurring on the inner hole of the oversized cylindrical forging during the shaping process, arc-shaped thin steel plates are provided on the end faces of the first end of the first shaping pad 8 and the first end of the second shaping pad 9. The shape of the arc-shaped thin steel plates matches the shape of the furnace wall of the heat treatment furnace to prevent indentations from occurring on the inner hole of the oversized cylindrical forging during the shaping process.

[0058] In order to maintain the deformation of the oversized cylindrical forging, the shaping unit also includes multiple support blocks and connecting blocks. After the oversized cylindrical forging is shaped, connecting blocks are welded between the second shaping pad 9 and the upper support steel plate 10 and between the second shaping pad 9 and the lower support steel plate 11, and the support blocks are used to replace the hydraulic jack 12; the connecting blocks are used to fix the size of the oversized forging after shaping.

[0059] It should be noted that the shape of the heat treatment furnace used in the present invention is not limited to a circular shape. Heat treatment furnaces of other shapes or gas furnaces of circular, rectangular, or other shapes may also be used. If a heat treatment furnace of another shape is used, the shape of the supporting steel plate, the placement of the annular support shims 1 and radial support shims 2, and the first and second shaping shims 8 and 9 may be adjusted appropriately based on actual conditions.

[0060] The present invention can adjust the number and position of the annular support washer 1 and the radial support washer 2 according to the diameter of the super-large cylindrical forging, change the size of the first shaping washer 8, the second shaping washer 9 and the arc-shaped steel plate, and realize the precise shaping of super-large cylindrical forgings with different diameters.

[0061] It should be noted that the diameter of ultra-large cylindrical forgings ranges from 7.0 to 11.5 meters, and their weight exceeds 100 tons. The diameter of an ultra-large cylindrical forging is determined by the forming equipment's capacity and the size of the heat treatment equipment. The forming equipment determines the resulting diameter of the forging, while the heat treatment equipment determines the diameter of the forging that can be stress-relieved. Based on the actual deformation of the ultra-large cylindrical forging, the height dimensions of the first and second shaping shims 8 and 9 can be varied, and the number of hydraulic jacks 12 can be increased, to achieve precise shaping of ultra-large cylindrical forgings within varying height ranges.

[0062] The first shaping shim 8 and the second shaping shim 9 have the same width and height but different lengths. The width and height of the first shaping shim 8 and the second shaping shim 9 are at least larger than the outline dimensions of the hydraulic jack 12. For the 500-ton hydraulic jack 12 used in the present invention, the width of the first shaping shim 8 and the second shaping shim 9 of the present invention is at least 400 mm, and the height of the first shaping shim 8 and the second shaping shim 9 is at least 700 mm. However, the larger the width and height, the greater the required shaping force, and the greater the capacity requirement for the hydraulic jack 12.

[0063] The present invention can change the shape and size of the ends of the first and second shaping washers 8, 9 according to the actual shape and size of the forging, thereby achieving precise shaping of large hollow forgings with different diameters and with variable diameters. It should be noted that in order to achieve the shaping of hollow forgings with variable diameters, the end surfaces of the first ends of the first and second shaping washers 8, 9 can be machined into the desired shape, or support blocks of the desired shape can be added to the edges of the first end surfaces.

[0064] In order to ensure the versatility of the first and second shaping washers 8 and 9, when shaping the variable diameter forging, a support block is added that matches the shape of the inner surface of the short shaft 5 of the super-large cylindrical forging; for example, Figure 7As shown, a first support block 16, a second support block 17 and a third support block 18 are provided on the inner surfaces of both ends of the short axis 5 of the oversized cylindrical forging with variable diameter. The first support block 16, the second support block 17 and the third support block 18 are stacked in sequence from bottom to top, and the edges of the first support block 16, the second support block 17 and the third support block 18 are in contact with the inner surface of the short axis 5 of the oversized cylindrical forging with variable diameter; for oversized cylindrical forgings of other sizes, by changing the size and number of the support blocks, the size of the shaping shims does not need to be redesigned, thereby increasing the versatility of the first shaping shims 8 and the second shaping shims 9, so that the shaping tooling is suitable for a variety of oversized cylindrical forgings with variable diameters.

[0065] It should be noted that the heat treatment furnace in this application is a large, circular furnace. To accommodate workpiece loading, the furnace bottom and shell are relatively movable. If a circular furnace is unavailable, a rectangular or other electric furnace, or a circular, rectangular, or other gas-fired furnace, may be used. If a heat treatment furnace of another shape is used, the placement of the annular and radial support shims can be adjusted appropriately based on actual conditions.

[0066] Example 2

[0067] This embodiment provides a method for correcting the shape of an oversized cylindrical forging, using the correction tool for correcting the shape of an oversized cylindrical forging provided in Example 1. The method includes the following steps:

[0068] Step 1: Before loading into the furnace, measure the size of the oversized cylindrical forging, determine the major axis and minor axis 5 of the oversized cylindrical forging, and mark the major axis and minor axis 5 of the forging on the inner and outer surfaces;

[0069] Step 2: When loading the furnace, place an annular support steel plate 3 on the heat treatment furnace, evenly distribute annular support shims 1 on the annular support steel plate 3, and place radial support shims 2 in the direction of the minor axis 5 of the oversized cylindrical forging; place a spirit level 7 on the radial support shim 2 at the center of the furnace bottom 6 of the heat treatment furnace;

[0070] Step 3. Use the spirit level 7 to check the height of all the annular support washers 1. If the heights of the annular support washers 1 are consistent, remove the spirit level 7 and place the oversized cylindrical forging on the annular support washers 1. If the heights of the annular support washers 1 are inconsistent, find the highest annular support washers 1 and use it as a benchmark, record the heights of the other annular support washers 1 that need to be filled, and fill the heights with thin steel plates.

[0071] Step 4: Use the shape correction unit to correct the shape of the super-large cylindrical forging;

[0072] The first shaping pad 8 and the second shaping pad 9 are placed on different radial support pads 2 respectively; a large-tonnage hydraulic jack 12 (500 tons) is placed between the upper support steel plate 10 and the lower support steel plate 11 of the first shaping pad 8, and the shaping process is carried out.

[0073] The shaping process is as follows: first apply pressure using the hydraulic jack 12 so that the first ends of the first shaping pad 8 and the second shaping pad 9 are in contact with the wall of the oversized cylindrical forging; first gradually increase the pressure, maintain the pressure for 101±min each time, and then measure the long axis size of the forging until the expected deformation is reached.

[0074] The hydraulic jack 12 increases the pressure to 10MPa±0.5MPa and maintains the pressure for 10min±1min, and detects the deformation of the long and short axes 5 of the forging; the hydraulic jack 12 increases the pressure to 20MPa±0.5MPa and maintains the pressure for 10min±1min, and detects the deformation of the long and short axes 5 of the forging;

[0075] The hydraulic jack 12 presses the pressure to 30MPa±0.5MPa and maintains the pressure for 10min±1min, and detects the deformation of the major and minor axes 5 of the forging; gradually increases the pressure and maintains the pressure for 10min±1min; after the hydraulic jack 12 increases the pressure to 60MPa±0.5MPa and reaches the stroke required for the expected deformation, stop pressurizing, maintain the pressure for 10min±1min, and detect the actual deformation of the forging.

[0076] Step 5: Welding connecting blocks between the upper support steel plate 10 and the second shaping pad 9 and between the lower support steel plate 11 and the second shaping pad 9;

[0077] Step 6: Remove the hydraulic jack 12 and place the support block;

[0078] Step 7: Perform stress relief heat treatment and remove the shaping tooling.

[0079] In step 7, the stress relief heat treatment process is as follows: the oversized cylindrical forging is kept at a temperature of 250-300° C. (e.g., 260° C. / h, 280° C. / h) for 4-4.5 hours; then the temperature of the heat treatment furnace is raised to 500-540° C. (e.g., 520° C. / h, 530° C. / h) at a rate of ≤55° C. / h (e.g., 50° C. / h, 45° C. / h), and kept at that temperature for 2-2.5 hours; then the temperature of the heat treatment furnace is raised to 550-600° C. (e.g., 560° C. / h, 580° C. / h) at a rate of ≤55° C. / h (e.g., 50° C. / h, 45° C. / h), and kept at that temperature for 9-9.5 hours; finally, the temperature of the heat treatment furnace is lowered to 350° C. at a rate of ≤55° C. / h, and the forging is air-cooled after being taken out of the furnace.

[0080] Example 3

[0081] This embodiment utilizes the shaping tooling for the oversized cylindrical forgings provided in Example 1 and the shaping method for the oversized cylindrical forgings provided in Example 2, and uses a hydraulic jack 12 to accurately shape the deformed oversized cylindrical forgings.

[0082] For example, a large cylindrical forging has an inner bore major axis of Φ8418mm and a minor axis of Φ8322mm after deformation. The forging is approximately 2170mm tall, 334mm thick, and weighs approximately 155 tons. The delivered inner bore dimension is Φ8400mm. After shaping, the target inner bore major axis dimension is Φ8390mm, with a 5mm margin on each side. The shaping process is as follows:

[0083] Step 1: Measure the size of the oversized cylindrical forging. Select a position on the forging as 0°, measure the diameter of the forging at certain angles in the circumferential direction and at certain distances in the height direction, record the position and diameter, and mark the inner hole and outer circle of the forging.

[0084] like Figure 4 、 Figure 5 As shown, in this example, 4 angles were selected in the circumferential direction and 3 sections were selected in the height direction to measure the inner hole size of the forging. The specific dimensions before correction are shown in Table 1 below:

[0085] Table 1 Inner hole dimensions in different directions before correction

[0086]

[0087]

[0088] The gauge data shows that the dimensions of the second and third sections (14 and 15) meet the delivery drawing requirements, but the dimensions of the first section (13) do not. To meet the finishing dimensions and allow approximately 5mm margin on one side, the area around section 1 requires reshaping. After reshaping, the target inner hole size is Φ8390mm.

[0089] Mark the long axis and short axis 5 directions of the super-large cylindrical forging on the inner and outer surfaces, place the end of the super-large cylindrical forging to be shaped downward, and turn the short axis 5 directions of the super-large cylindrical forging to the following positions: Figure 1 The alignment orientation shown;

[0090] Step 2: Place an annular support steel plate on the circular heat treatment furnace; evenly place 12 annular support pads 1 on the annular support steel plate; Figure 1 As shown; in the heat treatment furnace Figure 1 Place three radial support shims 2 and place the spirit level 7 on the radial support shim 2 at the center of the furnace bottom;

[0091] Step 3: Use a level 7 to check whether the heights of all the annular support shims 1 are basically consistent. If not, find the highest annular support shim 1 and use it as a reference to record the heights of the other annular support shims 1 that need to be filled up. Fill them with thin steel plates to make them into equal height planes.

[0092] Step 4: Use the shape correction unit to correct the shape of the super-large cylindrical forging;

[0093] Use an overhead crane to lift the oversized cylindrical forging and place it steadily on the annular support shim 1, check and level and pad the supporting parts of the forging; place the first shaping shim 8 and the second shaping shim 9 on different radial support shims 2 respectively; place a 500-ton hydraulic jack 12 between the upper support steel plate 10 and the lower support steel plate 11 of the first shaping shim 8, and implement the shaping process.

[0094] The above-mentioned shape correction process is as follows: ① The hydraulic jack 12 is first pressurized slowly to eliminate the assembly gap and make the internal support contact the cylinder wall of the oversized cylindrical forging; ② The hydraulic jack 12 is pressurized to 10MPa and maintained for 10 minutes to detect the deformation of the long and short shafts 5 of the cylinder section; ③ The hydraulic jack 12 is pressurized to 20MPa and maintained for 10 minutes to detect the deformation of the long and short shafts 5 of the cylinder section; ④ The hydraulic jack 12 is pressurized to 30MPa and maintained for 10 minutes to detect the deformation of the long and short shafts 5 of the cylinder section. ⑤ Gradually increase the pressure and maintain the pressure for 10 minutes. ⑥ After the hydraulic jack 12 is pressurized to 60MPa, the stroke required for the expected deformation is reached, stop pressurizing, maintain the pressure for 10 minutes, and detect the actual deformation of the forging.

[0095] Step 5: Welding connecting blocks between the upper support steel plate 10 and the second shaping pad 9 and between the lower support steel plate 11 and the second shaping pad 9;

[0096] Step 6: Remove the hydraulic jack 12 and place multiple support blocks at the original location of the hydraulic jack 12 to prevent deformation of the supporting steel plate during the subsequent stress relief heating process;

[0097] Step 7: Perform stress relief heat treatment and remove the shape correction tooling after heat treatment.

[0098] Perform stress relief heat treatment. The stress relief heat treatment method is as follows: Figure 5 As shown: the workpiece is kept at a temperature of 250-300℃ for 4h; then the temperature of the heat treatment furnace is raised to 510-530℃ at a rate of ≤55℃ / h and kept at this temperature for 2h; then the temperature of the heat treatment furnace is raised to 570-590℃ at a rate of ≤55℃ / h and kept at this temperature for 9h; finally the temperature of the heat treatment furnace is lowered to 350℃ at a rate of ≤55℃ / h, and the workpiece is taken out of the furnace and air-cooled; when it cools to room temperature, the shaping tool is removed; and the inner hole size of the forging is re-inspected.

[0099] The inner hole dimensions of the forging after correction are shown in Table 2 below:

[0100] Table 2 Inner hole dimensions in different directions after correction

[0101]

[0102] It can be seen from the inspection data that after correction, the dimensions of each section meet the requirements of fine processing, and the minimum inner hole size has a processing allowance of 4mm.

[0103] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A tool for correcting the shape of an oversized cylindrical forging, characterized in that: The shape correction tool is arranged in the heat treatment furnace; the shape correction tool comprises a forging support unit and a forging shape correction unit; the forging support unit is arranged below the super-large cylindrical forging; The forging support unit includes an annular support steel plate, a plurality of annular support washers and a plurality of radial support washers, wherein the annular support washers are uniformly distributed along the circumference of the annular support steel plate; and the radial support washers are uniformly distributed along the minor axis direction of the super-large cylindrical forging; The forging shape correction unit is located above the radial support pad in the super-large cylindrical forging; the forging shape correction unit is used to correct the shape of the super-large cylindrical forging; The forging shaping unit includes a first shaping washer and a second shaping washer; the first shaping washer and the second shaping washer are both in the shape of a cuboid; The first shaping pad, the second shaping pad, the annular support pad and the radial support pad are all provided with lifting ears on their sides to facilitate the lifting and movement of each support pad and shaping pad; The first end of the first shaping washer and the first end of the second shaping washer are both adjacent to the inner surface of the oversized cylindrical forging; the second end of the first shaping washer is adjacent to the second end of the second shaping washer; an upper support steel plate and a lower support steel plate are provided on the end surface of the second end of the first shaping washer, and a hydraulic jack is provided in the accommodation space formed by the upper support steel plate and the lower support steel plate; The first and second shaping washers have the same width and height but different lengths, and the widths and heights of the first and second shaping washers are at least greater than the outline dimensions of the hydraulic jack; The first end of the first shaping washer and the end surface of the second shaping washer are both provided with an arc-shaped thin steel plate, and the arc-shaped thin steel plate is used to prevent indentations from occurring in the inner hole of the forging during the shaping process; When the oversized cylindrical forging is a reducing forging, an external support block having a matching shape is provided at the contact point with the inner surface of the short shaft of the oversized cylindrical forging; The shaping unit further includes a plurality of support blocks and connecting blocks. After the oversized cylindrical forging is shaped, connecting blocks are welded between the second shaping pad and the upper support steel plate and between the second shaping pad and the lower support steel plate, and the support blocks are used to replace the hydraulic jack for support. The connecting block is used to fix the size of the oversized forging after shape adjustment; A hydraulic jack is used as a force source to apply force to the minor axis of the inner hole of the oversized cylindrical forging, causing elastic deformation of the cylindrical forging in the radial direction, with the minor axis extending and the major axis contracting. When the deformation reaches the predetermined target value, a connecting block is welded in the direction of the jack's force to maintain the deformation. The jack is then removed and a support block is added. The diameter range of super-large cylindrical forgings is 7.0~11.5m; the weight of super-large cylindrical forgings is greater than 100 tons.

2. The shape-correcting tool for super-large cylindrical forgings according to claim 1, characterized in that: The shape correction tool for the super-large cylindrical forging also includes a spirit level; The level is arranged on the radial support washer at the center of the heat treatment furnace; the level is used to detect whether the heights of the various circumferential support washer irons are the same.

3. A method for correcting the shape of an oversized cylindrical forging, characterized in that: The shaping tool for the super-large cylindrical forging according to claim 2 comprises the following steps: Step 1: Before loading into the furnace, measure the size of the super-large cylindrical forging, determine the major axis and minor axis of the super-large cylindrical forging, and mark the major axis and minor axis orientations on the inner and outer surfaces of the super-large cylindrical forging; Step 2: When loading the furnace, place an annular support steel plate on the heat treatment furnace, evenly distribute annular support shims on the annular support steel plate, and place radial support shims in the short axis direction of the oversized cylindrical forging; place a spirit level on the radial support shims at the center of the furnace bottom of the heat treatment furnace; Step 3: Use a level to check the height of all the annular support washers. If the heights of the annular support washers are consistent, remove the level and place the oversized cylindrical forging on the annular support washers. Step 4: Use the shape correction unit to correct the shape of the super-large cylindrical forging; Step 5: Welding connecting blocks between the upper support steel plate and the second shaping pad, and between the lower support steel plate and the second shaping pad; Step 6: Remove the hydraulic jack and place a support block at the original hydraulic jack position; Step 7: Perform stress relief heat treatment and remove the shape correction tooling after heat treatment.

4. The method for correcting the shape of an oversized cylindrical forging according to claim 3, characterized in that: In step 4, the first shaping shim and the second shaping shim are placed on the radial support shim; a hydraulic jack is placed in the accommodation space formed by the upper support steel plate and the lower support steel plate of the first shaping shim, and the shaping process is carried out.

5. The method for correcting the shape of an oversized cylindrical forging according to claim 3, wherein: In step 4, the shaping process is as follows: using a hydraulic jack to apply pressure so that the first ends of the first shaping shim and the second shaping shim are in contact with the cylinder wall of the oversized cylindrical forging; gradually increasing the pressure, maintaining the pressure for 10 minutes ± 1 minute each time, and then measuring the major axis size of the oversized cylindrical forging until the expected deformation is reached.

6. The method for correcting the shape of an oversized cylindrical forging according to claim 3, characterized in that: In step 4, the hydraulic jack is pressurized to 10±0.5 MPa and maintained for 10±1 min to detect the deformation of the major and minor axes of the forging; the hydraulic jack is pressurized to 20±0.5 MPa and maintained for 10±1 min to detect the deformation of the major and minor axes of the forging; Use the hydraulic jack to increase the pressure to 30±0.5MPa and maintain the pressure for 10±1min to detect the deformation of the major and minor axes of the forging; gradually increase the pressure and maintain the pressure for 10±1min; after the hydraulic jack increases the pressure to 60±0.5MPa and reaches the stroke required for the expected deformation, stop pressurizing and maintain the pressure for 10±1min to detect the actual deformation of the forging.

7. The method for correcting the shape of an oversized cylindrical forging according to claim 3, wherein: In step 7, the stress relief heat treatment process is as follows: the oversized cylindrical forging is kept at a temperature of 250-300° C. for 4-4.5 hours; then the temperature of the heat treatment furnace is raised to 500-540° C. at a rate of ≤55° C. / h and kept at that temperature for 2-2.5 hours; then the temperature of the heat treatment furnace is raised to 550-600° C. at a rate of ≤55° C. / h and kept at that temperature for 9-9.5 hours; finally, the temperature of the heat treatment furnace is lowered to 350° C. at a rate of ≤55° C. / h and the forging is taken out of the furnace and air-cooled.

8. The method for correcting the shape of an oversized cylindrical forging according to claim 3, wherein: In step 3, if the heights of the annular support washers are inconsistent, find the highest annular support washers as a benchmark, record the heights of the other annular support washers that need to be filled, and fill the heights with thin steel plates.

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