Composite forging process for large blade die roller

Abstract

The invention discloses a large blade die-roller composite forging process which is suitable for forging a large blade with the length larger than 1.5 m. A die forging and roller forging combined process is adopted for carrying out forging forming on a workpiece, and blank making and roller forging machining is carried out on a blank subjected to primary heating through a roller forging process. Then, a workpiece formed after blank making roll forging is subjected to local die forging through a die forging technology, and the workpiece obtained after local die forging is subjected to local forming machining through a forming roll; and the workpiece subjected to local forming is subjected to secondary heating, the workpiece subjected to secondary heating is subjected to local die forging through the die forging process, and then forming is conducted through the shape righting and trimming process. The forging force can be reduced to one third of that of an integral forging process; the tonnage of forging equipment is reduced, and the forging production cost of large blades is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of forging, in particular to a large blade die-roller composite forging process. Background Art

[0002] Blades are key components for energy conversion in aircraft engines, steam turbines and gas turbines. The current production process is mainly forging. At present, the forging of large blades over 1.5 meters requires large heavy equipment and large tables, large equipment and production capital investment, low efficiency, and limited production and manufacturing output. Take a 72-inch large blade as an example. Figures 1 to 10 The blade shown is about 2100 mm long, about 630 mm wide, and weighs about 500 kg. For small and medium-sized enterprises, it is impossible to produce large blades. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings and defects of the prior art and provide a large blade die-roll composite forging process. The large blade die-roll composite forging process adopts the method of blanking roll-die forging-forming roll-die forging, and changes the part with the largest forming force into roll forging, which greatly reduces the forging force and ensures the quality of forgings; it can reduce the forging force to one third of the overall forging process; it reduces the tonnage of forging equipment and reduces the production cost of large blades.

[0004] A large blade die-roller composite forging process is suitable for forging large blades over 1.5 meters. The workpiece is forged and formed by a process combining die forging and roll forging. The blank after primary heating is roll forged by a roll forging process. The workpiece formed by roll forging is partially die forged by a die forging process. The workpiece after partial die forging is partially formed by a forming roller. The partially formed workpiece is reheated, and then the secondary heated workpiece is partially die forged by a die forging process. It is then formed by a corrective trimming process.

[0005] Among them, the blank making roll forging process includes subjecting the blank after once heating to blank making through at least three roll forging passes, and forming it according to the roll forging sequence of ellipse, ellipse and circle, and forming the blank after once heating into three different sections for the formed blade along the length direction according to the blade top area, the middle blade shape area and the blade root area, to form a roll forged blank.

[0006] Among them, the length of the top area of ​​the blade corresponds to the cross-sectional length of the blade top; the length of the middle blade area is shortened according to the widening and lengthening values ​​of the blank during roll forging, so that the length after roll forging is consistent with the corresponding position of the blade, and the processing allowance is increased at the junction of large and small sections and a large fillet is retained; the cross-sectional area and length of the blade root area are consistent with the blade root.

[0007] After the blank is roll forged, the cross sections of the roll forged blank are formed with large rounded transitions, and each cross-sectional area of ​​the roll forged blank is larger than 20%-30% of the area of ​​the corresponding cross section of the blade.

[0008] Among them, the workpiece formed after the blank is roll forged is partially die forged by a die forging process, and the blade top part is forged, and two-station forming is adopted, including one-station upsetting and two-station bending upsetting; in the one-station upsetting, a predetermined thickness is added according to the thickness of the blade top blade profile, and the top blade profile is rolled out, and the top blade profile is a plane, and each section is relatively parallel; in the two-station bending upsetting, the top blade profile is bent and a predetermined amount of depression is generated; wherein, in the die forging of the blade top part, the blade root end of the roll forging blank has no deformation and is in a unidirectional free expansion and contraction state, that is, it is freely extended axially and fixed circumferentially by the die, so that the axis center is consistent with the blade top axis center.

[0009] The local forming process using forming rollers includes roll forging the blade profile of the portion connecting the blade root, namely the middle blade profile.

[0010] Wherein, when the forming roller is used for local forming processing, the blade tip part is clamped by a clamp, and the blade profile of the part connecting with the blade root is roll forged.

[0011] Among them, the die forging process is used to perform local die forging on the workpiece after secondary heating, including local forging of the blade root and twisting the blade middle blade profile, which is completed by one or two die forging passes to complete the blade root and the blade middle blade profile torsion angle forging; wherein, when forging the blade root, the blade profile is axially extended and the blade top part is in an axially free state.

[0012] The correction and trimming process includes local correction of the connection parts of each process after forging is completed, wherein the parts involved in the correction are in an axially free state, and a trimming correction composite die is used to perform correction and trimming of the blade.

[0013] The volume of the blank is 20-30% greater than the volume of the final forging.

[0014] The large blade die-roll composite forging process of the present invention adopts the method of blanking roller-die forging-forming roller-die forging for large blades, and changes the part with the largest forming force into roll forging, which greatly reduces the forging force and ensures the quality of forgings; it can reduce the forging force to one third of the overall forging process; it reduces the tonnage of forging equipment and reduces the production cost of large blades. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 , Figure 2 These are the first and second schematic diagrams of the large blade model processed and formed by the present invention.

[0016] Figure 3, Figure 4 These are the first and second schematic diagrams of the large blade formed by the present invention.

[0017] Figure 5 It is a side view schematic diagram of a large blade formed by processing according to the present invention.

[0018] Figure 6 It is a schematic diagram of a large blade with cross-sectional position markings formed by the present invention.

[0019] Figures 7 to 10 for Figure 6 Cross-sectional views at four cross-sectional locations.

[0020] Fig.11 The present invention is a flow chart of the large blade die-roller composite forging process.

[0021] Fig.12 This is a model diagram of a roll forging blank formed in the roll forging blank making stage of the present invention.

[0022] Fig.13 It is a schematic diagram of a roll forging blank formed in the roll forging blank making stage of the present invention.

[0023] Figures 14 to 16 It is a schematic diagram of the extrusion deformation of the blank by the roll forging dies in different passes of the three-pass forming roll forging blank in the roll forging blank making stage of the present invention.

[0024] Fig.17 This is a schematic diagram of the blade tip of the workpiece after partial forging of the blade tip part.

[0025] Fig.18 , Fig.19 They are schematic diagrams of the blade tip cross-section after forging at one and two stations in the local forging process of the blade tip part.

[0026] Fig. 20 It is a schematic diagram of the workpiece after roll forging and the blade root connection part.

[0027] Fig.21 It is a schematic cross-sectional diagram of the middle blade profile after roll forging and the blade root connection part.

[0028] Fig. 22 This is a schematic diagram of the cross section after the blade root is partially forged and the middle part of the blade is twisted to form a twist angle.

[0029] Fig.23 This is a schematic diagram of the workpiece formed after partial forging of the blade root and twisting of the middle blade profile. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] See also Fig.11 As shown, a large blade die-roll composite forging process is suitable for forging large blades over 1.5 meters. The workpiece is forged and formed by a process combining die forging and roll forging. The blank after primary heating is roll forged by a roll forging process, and then the workpiece formed by roll forging is partially die forged by a die forging process, and the workpiece after partial die forging is partially formed by a forming roller; the partially formed workpiece is secondary heated, and then the secondary heated workpiece is locally die forged by a die forging process, and then formed by a corrective trimming process.

[0032] The primary heating and secondary heating mentioned above can be heating the blank or workpiece to between 1150-1200°C, the blank is made of steel material, and the volume of the blank is 20-30% greater than the volume of the final forging.

[0033] In a preferred embodiment, the blank making roll forging process includes rolling the blank through at least three passes after the primary heating, forming the blank according to the roll forging sequence of ellipse, ellipse, and circle, and forming the blank after the primary heating along the length direction into three different sections for the formed blade according to the blade top area A, the middle blade area B, and the blade root area C, to form a roll forging blank. In the present application, the roll forging blank making stage preferably adopts three passes of roll forging, and the roll forging process is formed according to the deformation mode of each pass of roll forging elongation of ellipse, ellipse, and circle, such as Figures 14 to 16 As shown, the final roll forging is formed as Fig.12 as well as Fig.13 Blank shown.

[0034] In a preferred embodiment, the roll forging is performed as follows Fig.12 as well as Fig.13 For the blank shown in the figure, the length of the top area of ​​the blade corresponds to the cross-sectional length of the blade top of the final formed blade; the length of the middle blade area is shortened according to the width and length of the blank during roll forging, so that the length after roll forging is consistent with the corresponding position of the final formed blade, and the processing allowance is increased at the connection between large and small sections and a large fillet is retained; the cross-sectional area and length of the blade root area are consistent with the final formed blade root, and can be directly forged after secondary heating.

[0035] The cross-section and length of the two ends of the blank formed by processing are consistent with the blade root and blade tip of the final product. The cross-section shape and length of the middle part of the blank should be modified accordingly according to the width and length of roll forging to ensure that the cross-section and length of the blade after roll forging are consistent. The width and length of blades at different positions are very different and need to be calculated according to the forging manual.

[0036] In a preferred embodiment, after the blank is roll forged, the blank is formed as follows Fig.12 as well as Fig.13 The cross sections of the R roll forging blank shown in the figure have large fillet transitions, and each cross-sectional area of ​​the roll forging blank is 20%-30% larger than the area of ​​the corresponding cross section of the blade. The present invention increases the margin and reserves large fillets at the positions where the cross sections of the blade parts change greatly, so as to avoid folding in the subsequent processing process, and the size of the fillets can be adjusted as needed.

[0037] In a preferred embodiment, the workpiece formed after the blank is roll forged is partially die forged using a die forging process, and the blade tip portion is forged using a two-station forming process, including a first-station upsetting process and a second-station bending upsetting process. In the first-station upsetting process, a predetermined thickness, such as 0.5 mm, is added to the blade profile thickness at the top of the blade, and a top blade profile is rolled out. The top blade profile is a plane, and each section is relatively parallel. In the second-station bending upsetting process, the top blade profile is bent and a predetermined amount of depression, such as 0.5 mm, is generated. In the die forging of the blade tip portion, the blade root end of the roll forging blank is not deformed and is in a unidirectional free telescopic state, that is, it is freely extended axially and fixed circumferentially by the die, so that the axis is consistent with the blade tip axis. The schematic diagram of the blade tip after local die forging is shown in the figure below. Fig.17 As shown, the schematic diagram of the blade tip cross section after one-station and two-station forging in the local forging process of the blade tip part is shown. Fig.18 , Fig.19 As shown, Fig.18 The middle is a schematic diagram of the blade formed after the flattening process (a side view of the workpiece). Fig.19 Schematic diagram of the bending of the blade formed after the flattening process (side view of the workpiece).

[0038] In a preferred embodiment, the local forming roller segment processing using the forming roller includes the roll forging of the blade profile at the connection part with the blade root. In this step process, the blank will be widened and lengthened when the middle part is roll forged, and the profile is parallel without twist angle. The blank diameter and length of the roll forging area are calculated according to the size of the final blade profile and the roll forging formula to ensure that the width and length from the blank to the roll forged blade profile are consistent with the blade profile. According to the blade size, the cross-sectional shape and length of the roll forged blank are appropriately adjusted.

[0039] In a preferred embodiment, when the forming roller is used for local (partial roll forging of the middle blade profile) forming processing, a clamp is used to clamp the blade tip portion, and the blade profile connecting the blade root is roll forged, wherein the clamp is made according to the shape of the forged blade tip to ensure the stability of clamping; after roll forging, the sections of the blade profile are relatively parallel, without twist angle, and the sections are relatively parallel, such as Fig.21As shown, when the blade root is die-forged in the next process, the torsion angle of the profile is forged. After the blade tip is clamped by the pliers for roll forging, the root blank will bend to a certain extent, but it will not affect the forging of the next process. If the bending degree is large, a simple straightening process can be added.

[0040] In a preferred embodiment, the die forging process is used to perform local die forging on the workpiece after secondary heating, including local forging of the blade root and the twisted blade middle blade shape, which is completed by one or two passes of die forging to complete the blade root and the blade middle blade shape twist angle forging. The blade shape after die forging in this step is as follows: Fig. 22 When forging the blade root, the blade tip and blade profile will still be axially extended. Therefore, the axial free state should be maintained, that is, the blade profile is axially extended and the blade tip is in an axially free state. The roll forging length can be shortened according to the extended length, and then the blank length can be adjusted.

[0041] In the partial die forging of the blade root in this step, the blade root is mainly forged locally and the blade profile in the middle of the blade is twisted. When twisting the blade profile in the middle of the blade, it is completed in one or two passes according to the condition of the blade. When forging the blade root, the blade profile is extended axially, and the blade top part should be in an axially free state to prevent the blade profile from piling up and affecting the streamline.

[0042] In a preferred embodiment, the shaping and trimming process includes local correction of the connecting parts of each process after forging is completed, wherein the part involved in the correction is in an axially free state, and a trimming and trimming composite die is used to perform the shaping and trimming of the blade. In the present application, after the root part of the blade is forged, the connecting parts of each process are locally corrected, wherein the part involved in the correction should be in an axially free state to ensure the integrity of the streamline; a trimming and trimming composite die is used to complete the shaping and trimming of the blade, and finally the workpiece is formed.

[0043] It should be noted that in the embodiment of the present application, in the die forging process, the portion that does not participate in the deformation in each step is in an axially free state and is die forged by means of circumferential die limiting (with a gap of approximately 1 mm), to ensure that the portion that does not participate in the deformation can extend axially freely without material accumulation, thereby ensuring the integrity of the streamline.

[0044] Among them, during forging, according to the different extension amounts of different blades, corresponding adjustments are made to the corresponding positions of the blank after calculation.

[0045] Among them, in the forging process of the present invention, the forging processing connection of each station must maintain the required forging temperature and be controlled within three fires as required.

[0046] In addition, in the specific implementation, at the position where each workstation is deformed and connected, a supplementary correction process can be performed at the connection position when necessary.

[0047] The process of the present invention combines die forging with roll forging. When the blade is formed, the horizontal surface is rolled out first, and then the torsion angle is forged. At the same time, the axial free forging method is adopted, which can realize the forming of large blades, and the part with the largest forming force is changed to roll forging, which further reduces the forging force and can reduce the forging force to one third of the overall forging.

[0048] The basic principles and main features of the present invention and the advantages of the present invention are shown and described above. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is therefore intended that all changes falling within the meaning and range of equivalent elements of the claims are included in the present invention.

[0049] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. Large blade die-roller composite forging process, characterized in that: It is suitable for forging large blades over 1.5 meters. The workpiece is forged and formed by a process combining die forging and roll forging. The blank after primary heating is roll forged by roll forging, and then the workpiece formed by roll forging is partially die forged by die forging. The workpiece after partial die forging is partially formed by using forming rollers; the partially formed workpiece is reheated, and then the workpiece after secondary heating is partially die forged by die forging, and then formed by the corrective trimming process.

2. The large blade die-roller composite forging process according to claim 1 is characterized in that: The blank making roll forging process includes subjecting the blank after once heating to blank making through at least three roll forging passes, and forming the blank according to the roll forging sequence of ellipse, ellipse and circle, and forming the blank after once heating into three different sections for the formed blades along the length direction according to the blade top area, the middle blade shape area and the blade root area, to form a roll forged blank.

3. The large blade die-roller composite forging process according to claim 2 is characterized in that: The length of the top area of ​​the blade corresponds to the cross-sectional length of the blade top; the length of the middle blade area is shortened according to the width and length of the blank during roll forging, so that the length after roll forging is consistent with the corresponding position of the blade, and the machining allowance is increased at the junction of large and small sections and a large fillet is retained; The cross-sectional area and length of the blade root region are consistent with the blade root.

4. The large blade die-roller composite forging process according to claim 3 is characterized in that: After the blank is roll forged, the cross sections of the formed roll forged blank have large rounded transitions, and each cross-sectional area of ​​the roll forged blank is larger than 20%-30% of the area of ​​the corresponding cross section of the blade.

5. The large blade die-roller composite forging process according to claim 1 is characterized in that: The workpiece formed after the blank is roll forged is partially die forged by a die forging process, and the blade tip part is forged, and two-station forming is adopted, including a first-station upsetting and a second-station bending upsetting; in the first-station upsetting, a predetermined thickness is added according to the thickness of the blade top blade profile, and the top blade profile is rolled out, and the top blade profile is a plane, and each section is relatively parallel; in the second-station bending upsetting, the top blade profile is bent and a predetermined amount of depression is generated; wherein, in the die forging of the blade tip part, the blade root end of the roll forging blank is not deformed and is in a unidirectional free expansion and contraction state, that is, it is freely extended axially and fixed circumferentially by the die, so that the axis is consistent with the axis of the blade tip.

6. The large blade die-roller composite forging process according to claim 1 is characterized in that: The local forming process using the forming roller includes roll forging the blade profile of the portion connecting the blade root, namely the middle blade profile.

7. The large blade die-roller composite forging process according to claim 6 is characterized in that: When the forming roller is used for local forming processing, the blade tip part is clamped by a clamp, and the blade profile of the part connecting with the blade root is roll-forged.

8. The large blade die-roller composite forging process according to claim 1 is characterized in that: The die forging process is used to perform local die forging on the workpiece after secondary heating, including local forging of the blade root and twisting the blade middle blade profile, which is completed by one or two die forging passes to complete the blade root and the blade middle blade profile twisting angle forging; wherein, when forging the blade root, the blade profile is axially extended and the blade top part is in an axially free state.

9. The large blade die-roller composite forging process according to claim 1 is characterized in that: The correction and trimming process includes performing local correction on the connecting parts of each process after forging is completed, wherein the part involved in the correction is in an axially free state, and a trimming correction composite die is used to perform the correction and trimming of the blade.

10. The large blade die-roller composite forging process according to claim 1 is characterized in that: The volume of the billet is 20-30% greater than the volume of the final forging.

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