Blank design method for improving uniformity of centrifugal impeller die forging

Abstract

The invention discloses a rough blank design method for improving the uniformity of a centrifugal impeller die forging, and belongs to the technical field of impeller die forging. The problems that in the prior art, due to the fact that centrifugal impeller die forgings are uneven in structure, great hidden dangers exist in safe use of parts, and the forging cost is high are solved. Comprising the following steps that S1, a small deformation area is recognized through the digital simulation technology; S2, a first groove and a second groove are formed in the upper end and the lower end of the small deformation area; S3, the top face of the first groove and the top face of the second groove are obliquely arranged; S4, the outer side walls of the first groove and the second groove are obliquely arranged away from the center lines; the rough blank design method for improving the uniformity of the centrifugal impeller die forging is used for centrifugal impeller die forging, rough blank and forging blank coordinated design is adopted, pre-forging and finish forging complementary deformation is utilized, the structure uniformity of the centrifugal impeller die forging is effectively improved, accordingly, the mechanical property of the centrifugal impeller die forging is improved, meanwhile, the forging cost is reduced, and the product quality is improved. The production efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of impeller die forging, and in particular relates to a blank design method for improving the uniformity of centrifugal impeller die forgings. Background Art

[0002] The centrifugal impeller is an integrated forging of the blade disk and shaft with a complex cross-sectional shape and a large difference in cross-sectional thickness. It is difficult to control the uniformity of deformation of this type of forging. The centrifugal impeller die forging uses a die to form the blank on a special die forging equipment. The die includes an upper die and a lower die used in conjunction with each other. The upper die includes an upper groove, and the upper groove is relatively provided with a first step, a second step and a third step horizontally. The lower die includes a lower groove, and the lower groove is relatively provided with a fourth step and a fifth step horizontally, and the centers of the upper groove and the lower groove are aligned. It is difficult to achieve uniform deformation of all parts with conventional incoming material cakes and die forging processes. In particular, during die forging, the deformation of the core of the cake is small, and the grains are not easy to break and recrystallize, resulting in uneven microstructures in different parts of the forging, which is manifested in large differences in mechanical properties at different positions, easy retention of raw material microtextures, and low abundance of mechanical properties in the core. These problems pose great risks to the safe use of parts and shorten the service life of parts.

[0003] At present, there is a process method that uses isothermal forging to improve the uniformity of centrifugal impeller deformation. The main principle is that high-temperature forging makes the metal more fluid, controls the metal deformation rate and deformation amount within a certain range, and thus improves the uniformity of the forging. However, due to the complex cross-sectional shape of the centrifugal impeller, this method does not significantly improve the uniformity, especially the improvement of the core deformation of the centrifugal impeller is limited. In addition, the isothermal forging process has high requirements for forging equipment, high costs for mold use and centrifugal impeller forging, and low production efficiency. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a blank design method for improving the uniformity of centrifugal impeller die forgings, improving the uniformity of the structure of centrifugal impeller die forgings, improving the mechanical properties of centrifugal impeller die forgings, reducing forging costs, and improving production efficiency.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The present invention discloses a blank design method for improving the uniformity of a centrifugal impeller die forging, comprising an upper die and a lower die used in combination, wherein the upper die is provided with an upper groove, and a first step, a second step and a third step are sequentially provided along the groove edge of the upper groove, and the lower die is provided with a lower groove, and a fourth step and a fifth step are sequentially provided along the groove edge of the lower groove, and the upper groove and the lower groove are coaxial, comprising the following steps:

[0007] S1. Using digital simulation technology to perform numerical simulation on the cake blank and identify the small deformation area of ​​the cake blank;

[0008] S2, a first groove and a second groove are arranged at the upper and lower ends of the small deformation zone, the cake blank is placed on the lower mold, and when the upper mold and the lower mold are butted, the first groove corresponds to the upper groove, the second groove corresponds to the lower groove, and the upper groove, the first groove, the second groove and the lower groove are coaxial;

[0009] S3, the top surface of the first groove is tilted downward, the inner edge of the top surface of the first groove is higher than the outer edge, the top surface of the second groove is tilted upward, the inner edge of the top surface of the second groove is lower than the outer edge, after the cake blank is placed in the lower mold, the top surface of the second groove is partially in contact with the fourth step;

[0010] S4, the outer side wall of the first groove is inclined away from the center line, the distance between the top end of the outer side wall of the first groove and the center line of the first groove is smaller than the distance between the bottom end thereof and the center line of the first groove, the outer side wall of the second groove is inclined away from the center line, the distance between the top end of the outer side wall of the second groove and the center line of the second groove is smaller than the distance between the bottom end thereof and the center line of the second groove;

[0011] S5. The design of the centrifugal impeller die forging blank is completed.

[0012] Furthermore, in step S2, the height of the cake blank is h, the depth of the first groove is a, 0.1h≤a≤0.55h, and the depth of the second groove is b, 0.08h≤b≤0.45h.

[0013] Furthermore, in step S2, the first groove and the second groove are trapezoidal grooves respectively matched with the upper groove and the lower groove, and the opening size of the trapezoidal groove is larger than the size of the groove bottom.

[0014] Furthermore, the top surface of the first groove is tangent to the inner edge of the first step of the upper mold.

[0015] Furthermore, the top surface of the first groove is inclined downward at an angle of δ, 0°<δ≤45°.

[0016] Furthermore, the outer side wall of the first groove is inclined at an angle of ε, 0°<ε≤45°.

[0017] Furthermore, the top surface of the second groove is tangent to the inner edge of the fourth step of the lower mold.

[0018] Furthermore, the top surface of the second groove is inclined upward at an angle of γ, 0°<γ≤30°.

[0019] Furthermore, the outer side wall of the second groove is inclined at an angle ζ, 0°<ζ≤60°.

[0020] Furthermore, a chamfer is arranged at a turning point between the top surface of the first groove and its outer side wall.

[0021] The beneficial effects of the present invention are:

[0022] The blank design method for improving the uniformity of centrifugal impeller die forgings provided by the present invention is used for the die forging of centrifugal impellers. During the die forging process, the first groove and the second groove are relatively arranged at the upper and lower ends of the small deformation zone of the blank, respectively corresponding to the upper groove cavity of the upper die and the lower groove cavity of the lower die, providing sufficient flow space for the deformation of the small deformation zone of the core of the blank, facilitating the deformation and flow of the small deformation zone of the core of the blank, greatly improving the axial deformation of the core by reverse extrusion, facilitating the grain crushing and recrystallization of the small deformation zone of the core of the blank, and improving the uniformity of the structure of the small deformation zone of the core of the blank; the top surface of the first groove corresponds to the first step of the upper die, the top surface of the second groove corresponds to the fourth step of the lower die, and the second groove The outer wall corresponds to the connecting part of the fourth step and the fifth step. During forging, the second groove end of the blank is directly placed on the lower groove of the lower die, the top surface of the second groove is in contact and fit with the fourth step part of the lower die (incompletely), the outer wall of the second groove is in contact and fit with the connecting part of the fourth step and the fifth step (incompletely), the top surface of the first groove of the upper die is pressed down to contact and fit with the first step part of the upper die (incompletely), so as to ensure that the blank is quickly positioned during forging, greatly reduce the positioning time of the blank, effectively reduce the temperature difference between the surface layer of the blank and its core, and further improve the uniformity of the deformation process of the blank; the top surface of the first groove is tilted downward, and the top surface of the second groove is tilted upward, so as to reduce the contact between the blank and the upper die The upper die is in contact with the lower die to prevent the rough billet from cooling too fast and affecting the uniform deformation, ensure that the rough billet has better fluidity during forging, and further improve the uniformity of the rough billet deformation process; the outer wall of the first groove is inclined away from the center line, and the outer wall of the second groove is inclined away from the center line. During forging, under the downward pressure of the upper die, the rough billet is better dispersed and flows in all directions, so that the deformation zone of the rough billet flows rapidly outward in the radial direction, and quickly fills the centrifugal impeller die forging cavity composed of the upper groove, the first step, the second step, the lower groove, the fourth step, and the fifth step, thereby slowing down the difference in deformation of each part of the rough billet, improving the uniformity of rough billet forging, and the rough billet flows in all directions to prevent depressions and folds on the side of the rough billet when it is deformed. defects, thereby ensuring the quality and mechanical properties of the forging blank made by rough forging; the rough blank design method for improving the uniformity of centrifugal impeller die forgings designed above can effectively improve the deformation uniformity of rough blank forging, and ensure that the forging blank made by rough blank die forging has a high degree of mechanical property abundance, thereby improving the quality of the centrifugal impeller and increasing the service life of the centrifugal impeller; adopting the coordinated design of rough blank pre-forging and forging blank, and utilizing the complementary deformation of rough blank pre-forging and forging blank final forging, effectively improving the organizational uniformity of the centrifugal impeller die forging, thereby improving the mechanical properties of the centrifugal impeller, increasing the safety reserve of the centrifugal impeller, and meeting the safe use of the centrifugal impeller; greatly reducing the time required for forging, reducing forging costs, and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 It is a process flow chart of a blank design method for improving the uniformity of a centrifugal impeller die forging provided by an embodiment of the present invention;

[0025] Figure 2 yes Figure 1 The iterative optimization diagram of the dough in the image becomes a rough dough;

[0026] Figure 3 is a front view of a blank provided by an embodiment of the present invention;

[0027] Figure 4 yes Figure 3 A schematic diagram of the inclination angles of the top surface and the outer side wall of the first groove and the top surface and the outer side wall of the second groove of the blank;

[0028] Figure 5 It is a schematic diagram of a blank provided by an embodiment of the present invention being forged between an upper die and a lower die;

[0029] Figure 6 yes Figure 5 A schematic diagram of the inclination angles of the top surface and the outer side wall of the first groove and the top surface and the outer side wall of the second groove of the blank;

[0030] Figure 7 is a front view of an upper mold and a lower mold provided by an embodiment of the present invention;

[0031] Figure 8 This is a rendering of a centrifugal impeller die forging part directly forged from a cake blank according to the background technology of the present invention;

[0032] Fig. 9 It is a rendering of a centrifugal impeller die forging provided by an embodiment of the present invention, in which a cake blank is designed into a blank and then the blank is forged into shape.

[0033] Figure markings: blank 1, first groove 101, top surface 1011 of the first groove, outer side wall 1012 of the first groove, second groove 102, top surface 1021 of the second groove, outer side wall 1022 of the second groove, upper mold 2, upper groove 201, first step 202, second step 203, third step 204, lower mold 3, lower groove 301, fourth step 302, fifth step 303. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0036] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 As shown, this embodiment provides a blank design method for improving the uniformity of centrifugal impeller die forgings, comprising an upper die 2 and a lower die 3 of regular shape used in conjunction with each other, the upper die being provided with an upper groove 201, along the groove edge of the upper groove 201 are provided with a first step 202, a second step 203 and a third step 204 rising in sequence, the lower die 3 being provided with a lower groove 301, along the groove edge of the lower groove 301 are provided with a fourth step 302 and a fifth step 303 rising in sequence, the upper groove 201 and the lower groove 301 being coaxial, comprising the following steps:

[0037] S1. numerically simulate the cake blank by using digital simulation technology to identify the small deformation area of ​​the cake blank; the shape of the cake blank is a regular shape, such as a square column;

[0038] S2, a first groove 101 and a second groove 102 are provided at the upper and lower ends of the small deformation zone, the cake blank is placed on the lower mold 3, and when the upper mold 2 and the lower mold 3 are butted, the first groove 101 corresponds to the upper groove 201, the second groove 102 corresponds to the lower groove 301, and the upper groove 201, the first groove 101, the second groove 102 and the lower groove 301 are coaxial; the first groove 101 and the second groove 102 are both through grooves;

[0039] S3, the top surface 1011 of the first groove 101 is tilted downward, the inner edge of the top surface 1011 of the first groove 101 is higher than its outer edge, the top surface 1021 of the second groove 102 is tilted upward, the inner edge of the top surface 1021 of the second groove 102 is lower than its outer edge, after the cake blank is placed on the lower mold 3, the top surface 1021 of the second groove 102 is partially (not completely) fitted with the fourth step 302; the inner edge of the top surface 1011 of the first groove 101 is close to the edge of the first groove 101, the first The outer edge of the top surface 1011 of the groove 101 is the edge away from the first groove 101, the inner edge of the top surface 1021 of the second groove 102 is the edge close to the second groove 102, and the outer edge of the top surface 1021 of the second groove 102 is the edge away from the second groove 102; the top surface 1011 of the first groove 101 is two top surfaces arranged relative to the center line of the first groove 101, the top surface 1021 of the second groove 102 is two top surfaces arranged relative to the center line of the second groove 102, and the center line of the first groove 101 and the center line of the second groove 102 are collinear;

[0040] S4, the outer side wall 1012 of the first groove 101 is inclined away from the center line, the distance between the top end of the outer side wall 1012 of the first groove 101 and the center line of the first groove 101 is smaller than the distance between the bottom end thereof and the center line of the first groove 101, the outer side wall 1022 of the second groove 102 is inclined away from the center line, the distance between the top end of the outer side wall 1022 of the second groove 102 and the center line of the second groove 102 is smaller than the distance between the bottom end thereof and the center line of the second groove 102; wherein, the bottom ends of the outer side walls on the same side of the first groove 101 and the second groove 102 are butted, and the first groove 101 and the second groove 102 share a bottom surface; the outer side walls 1012 of the first groove 101 are two outer side walls arranged relative to the center line of the first groove 101, and the outer side walls 1022 of the second groove 102 are two outer side walls arranged relative to the center line of the second groove 102;

[0041] S5. The design of the centrifugal impeller die forging blank 1 is completed.

[0042] Based on the above blank design method for improving the uniformity of centrifugal impeller die forgings, the blank is used for die forging of centrifugal impellers. During the die forging process, the first groove 101 and the second groove 102 are relatively arranged at the upper and lower ends of the small deformation zone of the blank 1, corresponding to the upper groove 201 cavity of the upper die 2 and the lower groove 301 cavity of the lower die 3, respectively, providing sufficient flow space for the deformation of the core small deformation zone of the blank 1, facilitating the deformation and flow of the core small deformation zone of the blank 1, greatly improving the axial deformation of the core by reverse extrusion, facilitating the grain crushing and recrystallization of the core small deformation zone of the blank 1, and improving the uniformity of the structure of the core small deformation zone of the blank 1; the top surface 101 of the first groove 101 is provided with a plurality of grooves 102, each of which is provided with a plurality of grooves 103, and the plurality of grooves 104 are provided with a plurality of grooves 105, 106 and 107. 11 corresponds to the first step 202 of the upper die 2, the top surface 1021 of the second groove 102 corresponds to the fourth step 302 of the lower die 3, and the outer side wall 1022 of the second groove 102 corresponds to the connecting portion of the fourth step 302 and the fifth step 303. During forging, the second groove 102 end of the blank 1 is directly placed on the lower groove 301 of the lower die 3, the top surface 1021 of the second groove 102 partially (incompletely) contacts and fits with the fourth step 302 of the lower die 3, and the outer side wall 1022 of the second groove 102 partially (incompletely) contacts and fits with the connecting portion of the fourth step 302 and the fifth step 303. The forging press presses down the top surface 1021 of the first groove 101 of the upper die 2. 11 is partially (incompletely) in contact with the first step 202 of the upper die 2, ensuring that the blank 1 is quickly positioned during forging, greatly reducing the positioning time of the blank 1, effectively reducing the temperature difference between the surface layer and the core of the blank 1, and further improving the uniformity of the deformation process of the blank 1; the top surface 1011 of the first groove 101 is tilted downward, and the top surface 1021 of the second groove 102 is tilted upward, reducing the contact between the blank 1 and the upper die 2 and the lower die 3, avoiding excessive cooling of the blank 1 and affecting the uniform deformation, ensuring that the blank 1 has better fluidity during forging, and further improving the uniformity of the deformation process of the blank 1; the outer wall 1012 of the first groove 101 is tilted away from the center line The outer side wall 1022 of the second groove 102 is inclined away from the center line. During forging, under the downward pressure of the upper die 2, the blank 1 is better dispersed and flows in all directions, so that the deformation area of ​​the blank 1 flows rapidly outward in the radial direction, and quickly fills the centrifugal impeller die forging cavity composed of the upper groove 201, the first step 202, the second step 203, the lower groove 301, the fourth step 302, and the fifth step 303, thereby reducing the difference in deformation of each part of the blank 1, improving the uniformity of the forging of the blank 1, and the blank 1 is dispersed and flows in all directions, preventing the side of the blank 1 from being concave, folded, and other defects when the blank 1 is deformed, thereby ensuring the quality and mechanical properties of the forging blank made by die forging of the blank 1;Through the blank design method for improving the uniformity of centrifugal impeller die forgings designed above, the square columnar incoming material cake is designed into a butterfly shape with wings that matches the cavity of the centrifugal impeller die forging, which effectively improves the deformation uniformity of the blank 1 forging, and ensures that the forging blank made by the blank 1 through die forging has a high mechanical property margin, thereby improving the quality of the centrifugal impeller and increasing the service life of the centrifugal impeller; the blank 1 pre-forging and the forging blank are coordinated in design, and the blank 1 pre-forging and the forging blank final forging are used to complement each other in deformation, which effectively improves the uniformity of the organization of the centrifugal impeller die forging, thereby improving the mechanical properties of the centrifugal impeller, improving the safety reserve of the centrifugal impeller, and meeting the safe use of the centrifugal impeller; the time required for forging is greatly reduced, the forging cost is reduced, and the production efficiency is improved. ;

[0043] As an implementation method, Figure 2 As shown, in step S2, the height of the cake blank is h, the depth of the first groove 101 is a, 0.1h≤a≤0.55h, and the depth of the second groove 102 is b, 0.08h≤b≤0.45h.

[0044] Among them, the depth a of the first groove 101 is 0.1h or 0.2h or 0.25h or 0.3h or 0.4h or 0.55h, etc., and the depth b of the second groove 102 is 0.08h or 0.16h or 0.20h or 0.24h or 0.32h or 0.45h, etc. The depth of the first groove 101 and the depth of the second groove 102 can be designed according to the specific size of the centrifugal impeller.

[0045] As an implementation method, Figure 4 , Figure 5 , Figure 7 As shown, in step S2, the first groove 101 and the second groove 102 are trapezoidal grooves respectively matched with the upper groove 201 and the lower groove 301, and the opening size of the trapezoidal groove is larger than the bottom size thereof.

[0046] The first groove 101 and the second groove 102 are trapezoidal grooves with an opening size larger than the groove bottom size, which is beneficial to the axial and axially dispersed deformation flow of the core small deformation zone of the blank, and further improves the uniformity of the structure of the core small deformation zone of the blank.

[0047] As an implementation method, Figure 4 , Figure 5 , Figure 6 As shown, the inner edge of the top surface 1011 of the first groove 101 is tangent to the inner edge of the first step 202 of the upper mold 2 .

[0048] After the upper die 2 is pressed on the top surface 1011 of the first groove 101 of the blank 1, the inner edge of the top surface 1011 of the first groove 101 is in tangential contact with the inner edge of the first step 202 of the upper die 2, so that the first groove 101 and the upper groove 201 remain relatively arranged, further reducing the contact between the blank 1 and the upper die 2, avoiding the blank 1 from cooling too quickly and affecting the uniform deformation, ensuring that the blank 1 has better fluidity during forging, and further improving the uniformity of the deformation process of the blank 1, wherein the inner edge of the first step 202 is the edge close to the upper groove 201, and the inner edge of the top surface 1011 of the first groove 101 is the edge close to the first groove 101.

[0049] As an implementation method, Figure 6 As shown, the top surface 1011 of the first groove 101 is inclined downward at an angle of δ, 0°<δ≤45°.

[0050] The downward tilt angle of the top surface 1011 of the first groove 101, that is, when the upper mold 2 presses down the top surface 1011 of the first groove 101 to partially (incompletely) contact and fit with the first step 202, the angle δ between the top surface 1011 of the first groove 101 and the first step 202, such as 5° or 10° or 30° or 45°, is designed according to the specific size of the centrifugal impeller.

[0051] As an implementation method, Figure 6 As shown, the outer side wall 1012 of the first groove 101 is inclined at an angle ε, 0°<ε≤45°.

[0052] The inclination angle ε of the outer side wall 1012 of the first groove 101 is, for example, 5°, 10°, 30° or 45°, designed according to the specific size of the centrifugal impeller.

[0053] As an implementation method, Figure 6 As shown, the top surface 1021 of the second groove 102 is tangent to the inner edge of the fourth step 302 of the lower mold 3 .

[0054] After the blank 1 is placed on the lower die 3, the inner edge of the top surface 1021 of the second groove 102 is partially (incompletely) fitted with the inner edge of the fourth step 302 of the lower die 3, further reducing the contact between the blank 1 and the lower die 3, avoiding the blank 1 from cooling down too quickly and affecting the uniform deformation, ensuring that the blank 1 has better fluidity during forging, and further improving the uniformity of the deformation process of the blank 1, wherein the inner edge of the top surface 1021 of the second groove 102 is the edge close to the second groove 102, and the inner edge of the fourth step 302 is the edge close to the lower groove 301.

[0055] As an implementation method, Figure 6 As shown, the top surface 1021 of the second groove 102 is inclined upward at an angle of γ, where 0°<γ≤30°.

[0056] The top surface 1021 of the second groove 102 is inclined upward at an angle γ, such as 5°, 10°, 20° or 30°, according to the specific design of the lower mold 3, so that the top surface 1021 of the second groove 102 is partially (incompletely) in contact with the fourth step 302 of the lower mold 3.

[0057] As an implementation method, Figure 6 As shown, the outer side wall 1022 of the second groove 102 is inclined at an angle ζ, 0°<ζ≤60°.

[0058] The outer wall 1022 of the second groove 102 is inclined at an angle ζ, such as 5°, 10°, 20°, 30°, 45° or 60°, according to the specific design of the lower mold 3 and in cooperation with γ, so that the outer wall 1022 of the second groove 102 is partially (incompletely) in contact with and fits the connecting part of the fourth step 302 and the fifth step 303 of the lower mold 3.

[0059] As an implementation method, Figure 4 As shown, the top surface 1011 of the first groove 101 and the outer side wall thereof are chamfered at the turning point.

[0060] The top surface 1011 of the first groove 101 and the outer side wall of the corresponding side are chamfered at the turning point to reduce damage to the upper die 2, reduce the replacement of the upper die 2, and reduce the die forging cost. Furthermore, the turning points of the blank 1 are all chamfered to reduce damage to the upper die 2 and the lower die 3.

[0061] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A blank design method for improving the uniformity of a centrifugal impeller die forging, comprising an upper die (2) and a lower die (3) used in combination, wherein the upper die is provided with an upper groove (201), and a first step (202), a second step (203) and a third step (204) are sequentially provided along the groove edge of the upper groove (201); the lower die (3) is provided with a lower groove (301), and a fourth step (302) and a fifth step (303) are sequentially provided along the groove edge of the lower groove (301); the upper groove (201) and the lower groove (301) are coaxial, and characterized in that: The following steps are involved: S1. Using digital simulation technology to perform numerical simulation on the cake blank and identify the small deformation area of ​​the cake blank; S2, a first groove (101) and a second groove (102) are arranged at the upper and lower ends of the small deformation zone, the cake blank is placed on the lower mold (3), and when the upper mold (2) and the lower mold (3) are butt-jointed, the first groove (101) corresponds to the upper groove (201), the second groove (102) corresponds to the lower groove (301), and the upper groove (201), the first groove (101), the second groove (102) and the lower groove (301) are coaxial; S3, the top surface (1011) of the first groove (101) is tilted downward, the inner edge of the top surface (1011) of the first groove (101) is higher than the outer edge, the top surface (1021) of the second groove (102) is tilted upward, the inner edge of the top surface (1021) of the second groove (102) is lower than the outer edge, and after the cake blank is placed on the lower mold (3), the top surface (1021) of the second groove (102) is partially in contact with the fourth step (302); S4, the outer side wall (1012) of the first groove (101) is arranged to be inclined away from the center line thereof, and the distance between the top end of the outer side wall (1012) of the first groove (101) and the center line of the first groove (101) is smaller than the distance between the bottom end thereof and the center line of the first groove (101); the outer side wall (1022) of the second groove (102) is arranged to be inclined away from the center line thereof, and the distance between the top end of the outer side wall (1022) of the second groove (102) and the center line of the second groove (102) is smaller than the distance between the bottom end thereof and the center line of the second groove (102); S5. The design of the centrifugal impeller die forging blank (1) is completed.

2. A blank design method for improving the uniformity of centrifugal impeller die forgings according to claim 1, characterized in that: In step S2, the height of the cake blank is h, the depth of the first groove (101) is a, 0.1h≤a≤0.55h, and the depth of the second groove (102) is b, 0.08h≤b≤0.45h.

3. A blank design method for improving uniformity of centrifugal impeller die forgings according to claim 1, characterized in that: In step S2, the first groove (101) and the second groove (102) are trapezoidal grooves respectively matched with the upper groove (201) and the lower groove (301), and the opening size of the trapezoidal groove is larger than the size of the groove bottom.

4. A blank design method for improving uniformity of centrifugal impeller die forgings according to claim 3, characterized in that: The top surface (1011) of the first groove (101) is tangent to the inner edge of the first step (202) of the upper mold (2).

5. A blank design method for improving uniformity of centrifugal impeller die forgings according to claim 4, characterized in that: The top surface (1011) of the first groove (101) is inclined downward at an angle of δ, 0°<δ≤45°.

6. A blank design method for improving uniformity of centrifugal impeller die forgings according to claim 5, characterized in that: The outer side wall (1012) of the first groove (101) is inclined at an angle of ε, 0°<ε≤45°.

7. A blank design method for improving uniformity of centrifugal impeller die forgings according to claim 3, characterized in that: The top surface (1021) of the second groove (102) is tangent to the inner edge of the fourth step (302) of the lower mold (3).

8. A blank design method for improving uniformity of centrifugal impeller die forgings according to claim 7, characterized in that: The top surface (1021) of the second groove (102) is inclined upward at an angle of γ, where 0°<γ≤30°.

9. A blank design method for improving uniformity of centrifugal impeller die forgings according to claim 8, characterized in that: The outer side wall (1022) of the second groove (102) is inclined at an angle ζ, 0°<ζ≤60°.

10. A blank design method for improving uniformity of centrifugal impeller die forgings according to claim 3, characterized in that: The top surface (1011) of the first groove (101) and the outer side wall thereof are chamfered at the turning point.

Images