A method for preventing deformation of a curved split mold long rod structure forging

Abstract

The application provides a deformation prevention forging method for a curve split mold long rod structure forging, which comprises the following steps: designing a mold structure according to the forging shape; designing a curve split mold long rod structure forging blank; designing a curve split mold long rod structure forging warping control scheme, which comprises a cooling and measuring scheme; forging the forging blank according to the curve split mold long rod structure forging blank; mold forging the forging based on the mold structure; and cooling and measuring the forging according to the curve split mold long rod structure forging warping control scheme. The mold designed in the application can effectively control the displacement of the long rod structure forging with a split mold line in the shape of a "7" to be within one fourth of the machining allowance after mold forging, and the cooling and measuring scheme can effectively control the warping of the long rod structure forging with a split mold line in the shape of a "7" to be within one third of the machining allowance after mold forging.

Description

Technical Field

[0001] This invention belongs to the field of hot forging technology and relates to a deformation-resistant forging method for long rod-shaped structural forgings with curved parting. Background Technology

[0002] The parting surface of the mold for forgings with curved parting lines for long rods is a curved surface with a "7"-shaped parting line. The "7"-shaped parting line is mainly composed of a long side and a short side, with the length of the long side being more than 1.5 times the length of the short side, and the included angle between the long and short sides being 95°~165°. The external shape of the forging with curved parting lines for long rods is a long rectangle, and the total length of the forging is more than 5 times the maximum width of the forging.

[0003] When the parting surface of the die is a flat plane, the force on the die during pressing is in the same direction as the impact direction of the equipment, i.e., a vertical force. In this case, the die experiences relatively uniform force, and the upper and lower dies are less likely to slip at the parting surface, thus reducing the likelihood of misalignment of the forging. Furthermore, more vertical force facilitates metal flow and improves the forming of the forging. However, when the parting surface of the die is curved, with some sections being inclined, the impact force on the inclined sections is decomposed into different directions during pressing, resulting in a force primarily composed of vertical and horizontal components. The horizontal component not only reduces the forming effect of the forging but also causes the die to slip along the parting surface, providing a certain slip force and ultimately causing misalignment of the forging. For forging equipment with high impact speeds, such as air-operated hammers, the degree of slippage in die forging is even more pronounced. Once misalignment occurs in a forging, it is almost impossible to correct it through die forging or other methods, especially when the under-pressure of the forging is too small in subsequent die forging cycles. In addition, if the misalignment of the forging is too large in the first few die forging cycles, severe "biting" will occur in localized areas of the forging during subsequent die forging cycles, which will also affect the service life of the die.

[0004] For long rod forgings with a large projected area, the varying cross-sections result in different amounts of residual stress generated during forging, and the different rates at which this residual stress is released during cooling. This makes them prone to warping after die forging. For long rod forgings with curved parting surfaces, improper cooling methods can lead to even more significant differences in heat dissipation rates at both ends, resulting in more severe warping deformation. While warping can be accurately measured without any auxiliary measuring tools for long rod forgings with flat parting surfaces, it becomes difficult to directly and accurately measure warping when the parting surface is curved, making it challenging to control during production. Although warping can be corrected through die forging, this increases manufacturing costs, prolongs the production cycle, and increases the risk of quality issues. For forgings made from materials with relatively low heat treatment temperatures, such as TC18, if warping is discovered only after heat treatment, the correction heating temperature must be lower than the heat treatment temperature to ensure performance is not affected. However, because the heating temperature is too low, it is usually impossible to correct the warping, requiring reforging, reheat treatment, and even re-physicochemical treatment, significantly reducing production efficiency. Furthermore, during the correction process, the forging is essentially in a "blank firing" state, which will adversely affect its internal structure. This is especially true for materials with high deformation requirements, such as A-100 and GH4169; each additional "blank firing" will cause significant grain growth, directly reducing performance levels.

[0005] Both misalignment and warpage deformation in forgings are surface quality defects. During subsequent part processing, these defects can result in varying degrees of missing material in certain areas of the forging, and in severe cases, can lead to the forging being scrapped. For forgings produced through multi-stage die forging, misalignment and warpage must be effectively controlled from the very beginning of the forging process. The earlier these defects are detected, the greater the potential for correction. Although misalignment and warpage are influenced by many factors and are difficult to completely avoid, identifying the main influencing factors and designing a reasonable and feasible forging production plan can control these two types of deformation within a certain range and ensure the smooth progress of subsequent part processing. Summary of the Invention

[0006] This invention provides a deformation-resistant forging method for long rod-shaped forgings with curved parting lines. This method controls the misalignment of the forging to within one-quarter of the machining allowance and the warpage to within one-third of the machining allowance, while achieving high production efficiency in manufacturing the hot-working portion. This invention is applicable to the forging production of long rod-shaped forgings with curved parting lines using various materials, ultimately ensuring that the internal and external quality of the forging meets the required standards. This invention is particularly beneficial for forgings with high material deformation resistance, low forging and heat treatment temperatures, small angles between the long and short sides of the parting line, and relatively long overall length. The technical solution is as follows: A method for forging a curved parting long rod-type structural forging to prevent deformation, comprising: Step 1: Design the mold structure based on the shape of the forging; Step 2: Design the rough shape of the curved parting long rod-type structure forging; Step 3: Design a warpage control scheme for curved parting long rod-type forgings, including cooling and measurement schemes; Step 4: Forging and roughing the forging according to the parting line of the long rod-type structure forging; Step 5: Perform die forging on the forging based on the mold structure; Step 6: Cool and measure the forging according to the warpage control scheme for long rod-type structural forgings with curved parting.

[0007] Step 1 specifically includes: Design the parting surface of the forging: Use the parting surface determined by the long side of the “7” shaped parting line as the horizontal parting surface, and use the parting surface determined by the short side of the “7” shaped parting line as the inclined parting surface. Design the upper and lower mold distribution scheme: the mold with the parting slope position higher than the parting horizontal plane is used as the upper mold, and the mold with the parting slope position lower than the parting horizontal plane is used as the lower mold; Design the mold locking mechanism: Design the upper mold locking mechanism as a concave locking mechanism 3, that is, the upper surface of the locking mechanism is lower than the parting surface of the mold; design the lower mold locking mechanism as a convex locking mechanism 4, that is, the upper surface of the locking mechanism is higher than the parting surface of the mold, and the longitudinal position of the locking mechanism cannot extend beyond the end of the inclined surface of the parting surface. The location of the external bridge structure of the mold cavity is designed as follows: the position of the bridge structure 5 at the end of the mold parting slope is designed to be horizontal.

[0008] In step 2, the rough shape section is calculated and designed based on the forging section, and the ratio between the two is 1.15~1.35. The rough shape has a regular "7" shape, consisting of a long side and a short side. The angle between the long side and the short side of the rough shape is not greater than the angle between the long side and the short side of the forging.

[0009] The cooling scheme is as follows: during cooling, long rod-shaped forgings are placed upright in the cooling area, that is, the parting surface is perpendicular to the horizontal plane. For forgings that require air cooling, a distance greater than the effective thickness of the forging is maintained between each forging. For forgings that require slow cooling, corresponding heat preservation measures are taken.

[0010] The measurement scheme is as follows: Warpage measurement fixture 6 is used to determine the degree of warpage of curved parting long rod-type structural forgings. Among them, the warpage measuring fixture 7 is designed according to the shape of the forging. The warpage measuring fixture has three straight reference lines, namely the A zero reference line, the B zero reference line, and a C measuring reference line. The A zero reference line and the B zero reference line are selected longitudinally on the end face of the long side of the forging. After the warpage measuring fixture is placed on the surface of the forging, the gap between the A and B zero reference lines and the surface of the forging is 0 mm. The C measuring reference line is selected on the end face of the short side of the forging. After the warpage measuring fixture is placed on the surface of the forging, the gap between the C measuring reference line and the surface of the forging is 1~4 mm. The length of all straight reference lines is between 20 mm and 100 mm. The dimensions of the warp measurement fixture also meet the following requirements: S1≤0.18L, S2≥0.4L, S3≤0.10L, L: Total length of the forging, S1: Distance from the zero baseline A to the end of the long side of the forging. S2: The distance between zero baseline A and zero baseline B. S3: C is the distance from the measurement baseline to the short side end of the forging.

[0011] In measuring the warpage of a forging, the warpage measuring fixture is placed on the surface of the forging, ensuring that the two zero reference lines A and B are completely in contact with the surface of the forging. Then, the actual gap between the C measurement reference line and the surface of the forging is measured. If the gap value is equal to the theoretical gap value at that point, the warpage of the forging is 0 mm. If the gap value is greater than or less than the theoretical gap value at that point, the difference between the two is taken as the actual warpage value of the forging.

[0012] Among them, the warp measuring fixture, except for the A zero reference line, B zero reference line and C measuring reference line, maintains a gap of more than 2mm between the position and the surface of the forging.

[0013] The warpage measurement fixture is made of sheet metal with a thickness of 1-3mm.

[0014] The beneficial effects are as follows: 1. This invention provides guidance for the forging process of long rod-shaped structural forgings with curved parting structures made of various metal materials; 2. The mold designed in this invention can effectively forge long rod-shaped structures with a parting line in the shape of a "7". The final misalignment after die forging is controlled within one-quarter of its machining allowance.

[0015] 3. The cooling method designed in this invention effectively controls the warpage of long rod-shaped forgings with a parting line in the shape of a "7" after die forging to within one-third of their machining allowance.

[0016] 4. The rough mold designed in this invention can play a good positioning role during die forging and initially avoids the possibility of significant deformation of the forging.

[0017] 5. The special warpage measuring fixture designed in this invention can accurately measure the actual warpage value of the forging, and the fixture is simple to manufacture and easy to operate.

[0018] 6. This invention provides a certain reference for the forging method of long rod-shaped structural forgings with an "M"-shaped parting line. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the forming method for a curved parting long rod-type forging.

[0021] Figure 2 A schematic diagram of the parting surface design for forgings.

[0022] Figure 3 This is a schematic diagram of the upper and lower mold distribution.

[0023] Figure 4 This is a schematic diagram of the upper mold structure.

[0024] Figure 5 This is a schematic diagram of the lower mold structure.

[0025] Figure 6 This is a schematic diagram showing the placement of forgings during die forging and cooling.

[0026] Figure 7 This is a schematic diagram of measuring the warpage of a forging using a special warpage measuring fixture.

[0027] Figure 8 This is a schematic diagram showing the shape and main dimensions of a slide rail forging.

[0028] Explanation of reference numerals in the attached figures: 1-Rough-shaped structure, 2-Curved parting long rod-type forging, 3-Concave locking, 4-Convex locking, 5-Bridge structure, 6-Warp measuring tool shape structure. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] The features and illustrative embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific setups and methods set forth below, but covers any improvements, substitutions, and modifications to structures, methods, and devices without departing from the spirit of the invention. Well-known structures and techniques are not shown in the drawings and the following description to avoid unnecessarily obscuring the invention.

[0031] This invention discloses a method for preventing deformation forging of long rod-shaped forgings with curved parting lines, comprising the following steps: Step 1: Design the mold structure based on the shape of the forging. The design concept is as follows: 1.1) Design the parting surface of the forging, such as Figure 2 As shown: The portion of the parting surface defined by the longer side of the "7"-shaped parting line is taken as the parting horizontal plane (e.g.) Figure 2 In fm1), the part of the parting surface defined by the short side of the “7”-shaped parting line is used as the parting slope (e.g. Figure 2 (fm2 in the text). This ensures that most areas of the mold are suppressed by vertical forces, reducing the generation of horizontal forces, decreasing the sliding forces between molds, reducing the degree of slippage of the billet within the mold cavity, and reducing the misalignment of the final forging. At the same time, more vertical forces also provide better forming conditions for the forging. In addition, making most of the parting surface horizontal also improves the stability of the rough die within the mold cavity, ensuring good positioning of the first forging pass and providing favorable forming conditions for subsequent forging passes.

[0032] 1.2) Design the upper and lower mold distribution scheme, see Figure 3 : The mold section with its parting slope higher than the parting horizontal plane is used as the upper mold (e.g., Figure 3 In the context of sm), the mold with the parting slope lower than the parting plane is used as the lower mold (e.g., Figure 3 (xm in the diagram). Thus, the force at the inclined plane will consist of a vertical force and a horizontal component opposite to the horizontal plane. If the mold with the inclined plane higher than the horizontal plane is used as the lower mold, the force at the inclined plane will consist of a vertical force and a horizontal component equal to the horizontal plane. This makes the forging more prone to "slippage" on the horizontal plane within the mold cavity, increasing the likelihood of misalignment and hindering forging material placement. Furthermore, according to the principle of least resistance in metal flow, if the mold with the inclined plane higher than the horizontal plane is used as the lower mold, the metal at the inclined plane will not easily fill the forming process.

[0033] 1.3) Design mold locking mechanism: The upper mold's locking mechanism is designed as a recessed locking mechanism 3 (e.g., Figure 4 That is, the upper surface of the latch is lower than the parting surface of the mold; the latch of the lower mold is designed as a convex latch 4 (e.g. Figure 5 This means that the upper surface of the latch is higher than the parting surface of the mold. Furthermore, the longitudinal position of the latch cannot extend beyond the end of the parting slope. Specifically: S = 10~80mm, where S is the longitudinal distance between the mold latch and the end of the parting slope.

[0034] In this way, the horizontal force generated at the inclined surface during the pressing process can be better "counteracted" by the convex locking buckle, reducing the possibility of the forging shifting towards the inclined end. If the locking buckle of the lower die is designed as a concave locking buckle, because the inner wall of the concave locking buckle is lower than the lowest line of the parting slope, during the pressing process, before the upper and lower dies are fully closed and the locking buckle has a chance to function, the horizontal force generated at the parting slope will hardly be counteracted. At this point, the forging has already experienced significant misalignment, which is difficult to "correct" later. In addition, if the locking buckle of the lower die is designed as a concave locking buckle, in order to ensure the strength of the die at the parting slope, the overall thickness of the lower die needs to be increased accordingly based on the height of the locking buckle, thus increasing the die manufacturing cost.

[0035] 1.4) Design of the external bridge compartment structure of the mold cavity at position 5: The bridge structure at the end of the parting slope is designed to be horizontal (e.g., ...). Figure 3 As shown), instead of extending along the slope of the mold cavity parting surface, firstly, it reduces the proportion of the parting surface and reduces the generation of horizontal force; secondly, the position of the locking buckle may cross the position of the bridge section, so that the horizontal force generated by the bridge section is almost not "cancelled", thus increasing the generation of sliding force.

[0036] Step 2: Design the rough shape of the curved parting line for long rod-type structural forgings: The rough shape section is calculated and designed based on the forging section, with a ratio between the two of 1.15 to 1.35. The rough shape has a regular "7" shape (e.g., ...). Figure 1 1) The rough mold is mainly composed of a long side and a short side. The angle between the long side and the short side of the rough mold cannot be greater than the angle between the long side and the short side of the forging, i.e.: β = α - (0°~5°), where α is the angle between the short side and the long side of the forging, and β is the angle between the short side and the long side of the rough mold. Otherwise, during the initial pressing of the first forging stage, the inclined cavity of the upper die will contact the upper end face of the short side of the rough mold too early, causing the long side of the rough mold to be in a state of uncontrolled stress, which can easily lead to displacement and twisting, directly affecting the positioning effect of the first forging stage and the final forming state of the forging. Similarly, if the rough mold is designed as a straight line, i.e., a "1" shape, the upper die will contact one end of the rough mold earlier during the first forging stage, leading to more serious quality problems.

[0037] Step 3: Design a warpage control scheme for curved parting line long rod-type forgings: 3.1) Cooling solution Long rod-shaped forgings primarily warp along their length, i.e., longitudinally. After die forging, the forging typically has a burr around its perimeter. During cooling, long rod-shaped forgings are placed upright in the cooling area, such as... Figure 6 As shown, the parting surface is perpendicular to the horizontal plane. For forgings requiring air cooling, a distance greater than the effective thickness of the forging must be maintained between each forging. For forgings requiring slow cooling, appropriate insulation measures (insulation cotton, iron boxes, etc.) should be taken. This ensures a more uniform heat dissipation rate and a more consistent release of internal residual stress during the cooling process. Furthermore, placing the forging on its side disperses its center of gravity longitudinally, preventing it from concentrating in one area and causing significant deformation and severe warping of the forging as a whole. If the forging is placed flat in the cooling area during cooling, with its long side completely in contact with the ground and its short side "tilted" up, the short side dissipates heat faster, releasing more internal residual stress. The center of gravity of the forging will also concentrate at the short side, further promoting deformation and affecting the overall warping of the forging.

[0038] 3.2) Measurement Scheme For long rod-shaped forgings with curved parting lines, a warpage measuring fixture 6 is needed to determine the degree of warpage. The external structure of the warpage measuring fixture is shown in [link to fixture description]. Figure 7 Warp measurement fixture 6 was used to measure the warp of the forging, see [reference]. Figure 7 The warpage measuring fixture 7 is designed based on the shape of the forging, and the design concept is as follows: The warp measurement fixture has three straight reference lines, namely two zero reference lines (e.g., Figure 7 A zero reference line (A and B) and a measurement reference line are selected on the end face of the forging along the longitudinal direction at one end of the long side. After placing the warpage measuring fixture on the surface of the forging, the gap between the two zero reference lines A and B and the surface of the forging is 0 mm; a measurement reference line C is selected on the end face of the forging along the short side (see A and B). Figure 7 In section C), after placing the warpage measuring fixture on the surface of the forging, the gap between the C measuring reference line and the surface of the forging is 1~4mm, and the length of all straight reference lines is between 20mm and 100mm. Additionally, the following conditions must be met: S1≤0.18L, S2≥0.4L, S3≤0.10L, L: Total length of the forging, S1: The distance from the zero baseline to the end of the long side of the forging.

[0039] S2: The distance between zero baseline A and zero baseline B.

[0040] S3: C is the distance from the measurement baseline to the short side end of the forging.

[0041] Apart from the three straight baselines A, B, and C, the remaining positions of the warp measuring fixture maintain a gap of at least 2mm between itself and the surface of the forging. The warp measuring fixture is made of 1-3mm thick sheet metal, which has the advantages of being lightweight and not easily deformed.

[0042] When measuring the warpage of a forging, place the warpage measuring fixture on the surface of the forging, ensuring that the two zero reference lines A and B are completely in contact with the surface of the forging. Then, use a feeler gauge to measure the actual gap between the C measurement reference line and the surface of the forging. If the gap value is equal to the theoretical gap value at that point, the warpage of the forging is 0 mm. If the gap value is greater than or less than the theoretical gap value at that point, the difference between the two is taken as the actual warpage value of the forging.

[0043] For example, a slide rail forging, material grade: Ti-6Al-4V, forging weight: 66Kg, the forging shape and main dimensions are shown in the figure below. Figure 8 As shown, the machining allowance on one side of the forging is 8.5mm, and the vertical dimension tolerance is: +4 -2 mm. The forging is a long rectangle, and its total length is 6.6 times its maximum width. The parting surface of the forging die is a "7"-shaped curved surface composed of a long side and a short side. The length of the long side is 2.6 times the length of the short side, which is a typical curved parting structure for long rod-type forgings.

[0044] 1) Design the mold based on the shape of the forging: The part of the parting surface defined by the long side of the "7"-shaped parting line, i.e., the end with dimension 800, is designated as the horizontal parting surface. The part of the parting surface defined by the short side of the "7"-shaped parting line is designated as the inclined parting surface. The mold section with the inclined parting surface higher than the horizontal parting surface is designated as the upper mold, and its locking mechanism is designed as a concave locking mechanism. The mold section with the inclined parting surface lower than the horizontal parting surface is designated as the lower mold, and its locking mechanism is designed as a convex locking mechanism. The longitudinal distance between the locking mechanism and the end of the inclined parting surface is designed to be 60mm. Finally, the bridge section at the end of the inclined parting surface is designed to be horizontal.

[0045] 2) Design the rough shape according to the dimensions of the forging: The ratio between the design rough section and the corresponding section of the forging is 1.20 to 1.28. The rough section has a shape that is a "7" shape composed of a long side and a short side, and the shape is regular. The angle between the long side and the short side of the rough section is 155°.

[0046] 3) Design a special warp measurement fixture based on the external dimensions of the forging.

[0047] The specialized warpage measuring fixture is made of 2mm thick sheet metal. It features two zero reference lines (A and B) and one measuring reference line (C). The gaps between the A and B zero reference lines and the surface of the forging are 0mm. The length of zero reference line A is 50mm, and the length of zero reference line B is 70mm. The distance from zero reference line A to the long side end of the forging is 180mm, and the distance between zero reference lines A and B is 470mm. The gap between the C measuring reference line and the surface of the forging is 3mm. The length of C measuring reference line is 40mm, and the distance from C measuring reference line to the short side end of the forging is 80mm. All other parts of the fixture maintain a gap of at least 3mm from the surface of the forging.

[0048] For example, the production process of slide rail forgings is as follows: Step 1: Cut the material using a saw. Material dimensions: Φ200×590; weight: 82Kg.

[0049] Step 2: Chamfer using a lathe, chamfer size: R10.

[0050] Step 3: Use a 3t free forging hammer to perform forging and roughing, heating temperature: 35℃ below the phase transformation point, completed in 3 heats. Forging and roughing first heat: forging the bar stock into a square shape; forging and roughing second heat: dividing and elongating the material; forging and roughing third heat: bending and shaping to the rough shape size.

[0051] Step 4: Forge the hammer with 630KJ steel at a heating temperature of 35℃ below the phase transformation point, completing the process in three passes. First pass: Leave a 15-20mm under-forging pressure on the forging; Second pass: Leave an 8-12mm under-forging pressure on the forging; Third pass: Forge the vertical dimensions to the required tolerance range. All three passes are air-cooled. After each pass, the forgings are placed upright in the cooling area, ensuring a gap of more than 130mm between them.

[0052] Step 5: Remove the burrs from the forging by gas cutting until the remaining burrs are 15~20mm.

[0053] Step 6: Remove the oxide scale from the surface of the forging using a sandblasting machine.

[0054] Step 7: Use a pneumatic drill to grind the surface of the forging until it is smooth.

[0055] Step 8: Heat treatment using an electric furnace, heat treatment regime: annealing.

[0056] Step 9: Remove the burrs from the forging using a milling machine until the remaining burrs are 0~2mm.

[0057] Step 10: Conduct physical and chemical tests.

[0058] Ultimately, the slide rail forgings for a certain type of machine were produced through two forging processes: rough forging and die forging. The rough forging process was stable in each heat, exhibiting good operability, and the dimensions of the forged rough conformed to design requirements. During die forging, the rough could be completely placed into the lower die cavity and remained stable. The positioning effect of the first die forging was good, with no significant forging displacement. After the third die forging, the forging was completely filled. Furthermore, with the increase in the number of die forging heats, the misalignment of the forging continuously decreased. After the third die forging, the measured misalignment was 1.5~2.0mm, and the actual warpage measured using a dedicated warpage measuring fixture was 2.0~2.5mm. In summary, the design of the rough, die, and dedicated warpage measuring fixture was reasonable and feasible, and the misalignment and warpage of the forging were all within a controllable range. Finally, physicochemical testing showed that the high-magnification and low-magnification microstructures of the forging met the standard requirements, and the performance data of the forging fully met the specified values ​​in the standard.

[0059] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the technical essence of the present invention should fall within the protection scope of the present invention.

Claims

1. A method for forging a curved parting long rod-shaped structural forging to prevent deformation, characterized in that, include: Step 1: Design the mold structure according to the shape of the forging; Step 2: Design the rough shape of the curved parting long rod-type structure forging; Step 3: Design a warpage control scheme for curved parting long rod-type forgings, including cooling and measurement schemes; Step 4: Forging and roughing the forging according to the parting line of the long rod-type structure forging; Step 5: Perform die forging on the forging based on the mold structure; Step 6: Cool and measure the forging according to the warpage control scheme for long rod-type structural forgings with curve parting.

2. The method according to claim 1, characterized in that, Step 1 is as follows: Design the parting surface of the forging: the parting surface determined by the long side of the "7"-shaped parting line is used as the horizontal parting surface, and the parting surface determined by the short side of the "7"-shaped parting line is used as the inclined parting surface. Design the upper and lower mold distribution scheme: the mold with the parting slope position higher than the parting horizontal plane is used as the upper mold, and the mold with the parting slope position lower than the parting horizontal plane is used as the lower mold; Design the mold locking mechanism: Design the upper mold locking mechanism as a concave locking mechanism, that is, the upper surface of the locking mechanism is lower than the parting surface of the mold; design the lower mold locking mechanism as a convex locking mechanism, that is, the upper surface of the locking mechanism is higher than the parting surface of the mold, and the longitudinal position of the locking mechanism cannot extend beyond the end of the inclined surface of the parting surface. The location of the external bridge structure of the mold cavity is designed to be horizontal.

3. The method according to claim 1, characterized in that, In step 2, the rough shape section is designed based on the forging section, and the ratio between the two is 1.15~1.

35. The rough shape has a regular "7" shape, consisting of a long side and a short side. The angle between the long side and the short side of the rough shape is not greater than the angle between the long side and the short side of the forging.

4. The method according to claim 1, characterized in that, The cooling scheme is as follows: During cooling, long rod-shaped forgings are placed upright in the cooling area, that is, the parting surface is perpendicular to the horizontal plane. For forgings that require air cooling, a distance greater than the effective thickness of the forging is maintained between each forging. For forgings that require slow cooling, corresponding heat preservation measures are taken.

5. The method according to claim 1, characterized in that, The measurement method is as follows: a warpage measurement fixture is used to determine the degree of warpage in curved parting long rod-shaped forgings. The warpage measurement fixture is designed according to the shape of the forging. The warpage measurement fixture has three straight reference lines, namely the A zero reference line, the B zero reference line, and a C measurement reference line. The A zero reference line and the B zero reference line are selected longitudinally on the end face of the long side of the forging. After the warpage measurement fixture is placed on the surface of the forging, the gap between the A and B zero reference lines and the surface of the forging is 0 mm. The C measurement reference line is selected on the end face of the short side of the forging. After the warpage measurement fixture is placed on the surface of the forging, the gap between the C measurement reference line and the surface of the forging is 1~4 mm. The length of all straight reference lines is between 20 mm and 100 mm. The dimensions of the warp measurement fixture also satisfy: S1≤0.18L, S2≥0.4L, S3≤0.10L, where L is the total length of the forging, S1 is the distance from the zero reference line A to the end of the long side of the forging, S2 is the distance between the zero reference line A and the zero reference line B, and S3 is the distance from the measurement reference line C to the end of the short side of the forging.

6. The method according to claim 5, characterized in that, When measuring the warpage of a forging, place the warpage measuring fixture on the surface of the forging, ensuring that the two zero reference lines A and B are completely in contact with the surface of the forging. Then measure the actual gap between the C measurement reference line and the surface of the forging. If the gap value is equal to the theoretical gap value at that point, the warpage of the forging is 0 mm. If the gap value is greater than or less than the theoretical gap value at that point, the difference between the two is taken as the actual warpage value of the forging.

7. The method according to claim 5, characterized in that, The warp measuring fixture, except for the zero reference line A, the zero reference line B, and the measuring reference line C, should maintain a gap of more than 2 mm between itself and the surface of the forging.

8. The method according to claim 5, characterized in that, The warpage measurement fixture is made of sheet metal with a thickness of 1-3mm.

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