CN112676505B

CN112676505B - Forging forming method

Info

Publication number: CN112676505B
Application number: CN202011315054.9A
Authority: CN
Inventors: 刘洪涛; 李萍
Original assignee: Shenyang Titanium Equipment Manufacturing Co ltd
Current assignee: Shenyang Titanium Equipment Manufacturing Co ltd
Priority date: 2020-11-20
Filing date: 2020-11-20
Publication date: 2023-06-09
Anticipated expiration: 2040-11-20
Also published as: CN112676505A

Abstract

The invention relates to the technical field of die forging processing, in particular to a forging forming method, which comprises the following steps: s1, preprocessing a blank, an upper die and a lower die; s2, placing the blank into a die cavity of the lower die, forging the blank for a plurality of times through a protruding part of the upper die until the upper die contacts with the lower die, and forming the blank into a bowl-shaped forging with reinforcing ribs. The closed precision die forging is formed by matching the protruding part of the upper die with the die cavity of the lower die, so that the problems that in the prior art, the bowl-shaped forging rib part with the reinforcing ribs is not fully filled, the damage and folding defects are easily caused, the titanium alloy forging is stuck to the die are solved, the trimming process is saved, and the obtained forging streamline is complete and has no cutting off.

Description

Forging forming method

Technical Field

The invention relates to the technical field of die forging processing, in particular to a forging forming method.

Background

At present, bowl-shaped parts with reinforcing ribs are generally formed in a casting mode, and die forging forming is considered because the aerospace project has higher requirements on tissue performance and quality. However, since titanium alloy is a rare and difficult-to-process metal material, the problem of molding the product is a technical problem facing a plurality of factories at present.

The rib part is easy to be filled and not full in the conventional die forging mode, the rib part is easy to be gnawed due to repeated forging, the bottom is easy to have folding defects, and the titanium alloy has the material characteristic of larger viscosity due to narrower inner cavity reinforcing ribs, so that the die is easy to be stuck, and the forging and the die are scrapped integrally.

The common open die forging has the excessive burr to produce, not only need the side cut process, increase one set of cut off die more. And the local deformation of the forging piece can be caused when the thin-wall piece is trimmed, and the final size is influenced. The metal at the forging burr is cut off, so that the forging streamline is cut off at the forging burr, and a part of performance loss is caused.

Disclosure of Invention

The invention provides a forging forming method, which is used for solving the defects that in the prior art, a bowl-shaped forging rib part with a reinforcing rib is not full and is easy to cause gnawing and folding defects, realizing closed precision die forging by matching a protruding part of an upper die with a die cavity of a lower die, solving the problems that in the prior art, the bowl-shaped forging rib part with the reinforcing rib is not full and is easy to cause gnawing and folding defects, and a titanium alloy forging is stuck to the upper die, saving a trimming procedure, and obtaining a forging streamline which is complete and has no cutting.

The invention provides a forging forming method, which comprises the following steps:

s1, preprocessing a blank, an upper die and a lower die;

s2, placing the blank into a die cavity of the lower die, forging the blank for a plurality of times through a protruding part of the upper die until the upper die contacts with the lower die, and forming the blank into a bowl-shaped forging with reinforcing ribs.

According to the forging forming method provided by the invention, the step S1 comprises the following steps: preheating the upper die and the lower die, wherein the preheating temperature is 200-250 ℃; heating the cake blank to 20-50 ℃ below the phase transition point, and preserving heat for 90-120 min to form the blank.

According to the forging forming method provided by the invention, in the step S1, the glass lubricant is uniformly coated before the cake blank is heated.

According to the forging forming method provided by the invention, in the step S2, after the blank is placed in the die cavity of the lower die, the upper surface of the blank is covered with the sheet-shaped solid graphite powder.

According to the forging forming method provided by the invention, in the step S2, the surface of the protruding part of the upper die is coated with the water-based graphite lubricant.

According to the forging forming method provided by the invention, after the step S2, the forging forming method further comprises the following steps:

s3, ejecting the forging from the lower die through an ejector rod;

s4, carrying out heat treatment on the forging.

According to the forging forming method provided by the invention, the step S4 comprises the following steps:

s41, primary annealing: heating the forging piece, wherein the heating temperature is 945-955 ℃, preserving heat for 1-1.5 hours, and air cooling;

s42, secondary annealing: heating the forging at 525-535 deg.c for 6-6.5 hr and air cooling.

According to the forging forming method provided by the invention, the forging forming method further comprises the following steps before the step S1:

s01, sawing bars with preset volumes;

s02, heating and upsetting the bar stock to form a cake blank, wherein the upsetting deformation is more than 50%.

According to the forging forming method provided by the invention, in the step S01, the preset volume is calculated volume after the height direction of the bowl-shaped forging with the reinforcing ribs is increased by 1.5-2.5 mm.

According to the forging forming method provided by the invention, in the step S02, the cross section area of the cake blank is larger than the end surface area of the ejector rod, and the diameter of the cake blank is 2-5 mm smaller than the diameter of the die cavity.

The invention provides a forging forming method, which is a forming method of a bowl-shaped forging with reinforcing ribs, wherein a pretreated blank is placed into a die cavity of a pretreated lower die, and then the blank is forged and pressed through a boss of a pretreated upper die until the die cavity is matched with the boss to form the blank into the bowl-shaped forging with the reinforcing ribs. The height dimension of the bowl-shaped forging with the reinforcing ribs is 70mm, the inner cavity is provided with 6 reinforcing ribs, the forming die is divided into an upper die and a lower die, the round table-shaped protruding part of the upper die is provided with 6 forming grooves for forming the reinforcing ribs, the lower die is provided with a round table-shaped die cavity for fixing the forging, and the forging is prevented from being dislocated under the condition of multiple forging, so that the reinforcing ribs are gnawed or the bottom is folded. The bulge of the upper die is matched with the die cavity of the lower die to form closed precise die forging, so that the problems that in the prior art, the bowl-shaped forging rib with the reinforcing ribs is not fully filled, the damage and folding defects are easily caused, the titanium alloy forging is stuck to the die are solved, the trimming process is saved, and the obtained forging streamline is complete and has no cutting off.

In addition to the technical problems, features of the constituent technical solutions and advantages brought by the technical features of the technical solutions described above, other technical features of the present invention and advantages brought by the technical features of the technical solutions will be further described with reference to the accompanying drawings or will be understood through practice of the present invention.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic structural view of a forging provided by the present invention;

FIG. 2 is a schematic structural view of the forging forming apparatus provided by the invention;

FIG. 3 is a schematic structural view of an upper die of the forging forming apparatus provided by the invention;

FIG. 4 is a schematic view of the structure of the lower die of the forging forming device provided by the invention;

reference numerals:

1: an upper die; 11: a boss; 12: a forming groove;

2: a lower die; 21: a mold cavity; 22: a through hole; 23: a bottom bulge;

3: forging pieces; 31: reinforcing ribs; 32: a positioning block; 33: the bottom is concave;

4: a push rod; 41: a rod body; 42: a platform; 43: and (5) recessing.

Detailed Description

Embodiments of the present invention are described in further detail below with reference to the accompanying drawings and examples. The following examples are illustrative of the invention but are not intended to limit the scope of the invention.

In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the embodiments of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In describing embodiments of the present invention, it should be noted that, unless explicitly stated and limited otherwise, the terms "coupled," "coupled," and "connected" should be construed broadly, and may be either a fixed connection, a removable connection, or an integral connection, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the above terms in embodiments of the present invention will be understood in detail by those of ordinary skill in the art.

In embodiments of the invention, unless expressly specified and limited otherwise, a first feature "up" or "down" on a second feature may be that the first and second features are in direct contact, or that the first and second features are in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the embodiments of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

As shown in fig. 1, 2, 3 and 4, the embodiment of the invention further provides a forging forming method, which includes:

s1, preprocessing a blank, an upper die 1 and a lower die 2;

s2, placing the blank into a die cavity 21 of a lower die 2, forging the blank for a plurality of times through a boss 11 of an upper die 1 until the upper die 1 is in contact with the lower die 2, and forming the blank into the bowl-shaped forge piece 3 with the reinforcing ribs 31.

The forging forming method of the embodiment of the invention is a forming method of a bowl-shaped forging with reinforcing ribs, wherein a pretreated blank is placed into a die cavity 21 of a pretreated lower die 2, and then the blank is forged and pressed through a boss 11 of a pretreated upper die 1 until the die cavity 21 is matched with the boss 11 to form the blank into the bowl-shaped forging 3 with the reinforcing ribs 31. The height dimension of the bowl-shaped forging with the reinforcing ribs is 70mm, the inner cavity is provided with 6 reinforcing ribs 31, the forming die is divided into an upper die 1 and a lower die 2, 6 forming grooves 12 are formed in the round table-shaped protruding portion 11 of the upper die 1 and are used for forming the reinforcing ribs 31, the lower die 2 is provided with a round table-shaped die cavity 21 and is used for fixing the forging 3, and the forging 3 is prevented from being dislocated under the condition of repeated forging, so that the reinforcing ribs 31 are gnawed or folded at the bottom. The bulge 11 of the upper die 1 is matched with the die cavity 21 of the lower die 2 to form closed precision die forging, so that the problems that in the prior art, a bowl-shaped forging rib with a reinforcing rib is not fully filled, the damage and folding defects are easily caused, the titanium alloy forging 3 is stuck to the die, the trimming process is saved, and the streamline of the obtained forging 3 is complete and has no cutting off are solved.

In this embodiment, to prevent the forging 3 from adhering to the upper die 1, a combined draft of the upper die 117 °, the lower die 217 ° and 3 ° is used.

According to an embodiment of the present invention, step S1 includes: preheating an upper die 1 and a lower die 2, wherein the preheating temperature is 200-250 ℃; heating the cake blank to 20-50 ℃ below the phase transition point, and preserving heat for 90-120 min to form a blank. In this embodiment, after the cake blank is heated and kept warm to form a blank, the blank is discharged and rapidly transferred into the cavity 21 of the lower die 2, and the center of the blank is ensured to coincide with the center of the cavity 21 of the lower die 2.

According to one embodiment of the present invention, in step S1, the glass lubricant is uniformly applied to the biscuit before heating. In step S2, the blank is placed in the cavity 21 of the lower die 2, and then a sheet-like solid graphite powder is coated on the upper surface of the blank. In step S2, the surface of the boss 11 of the upper mold 1 is coated with a water-based graphite lubricant.

In this embodiment, the cake blank needs to be evenly coated with glass lubricant before being heated in the furnace, the surface of the boss 11 of the upper die 1 is coated with water-based graphite, flaky solid graphite powder is sprayed on the upper surface of the blank during die forging, and the combination of different draft angles of 217 DEG and 3 DEG of the upper die 1 and the lower die is matched, so that the problem that the forging 3 is adhered to the upper die 1 is solved, meanwhile, redundant metal generated by burrs is saved, a set of trimming tool and trimming working procedure are saved, the integrality of streamline of the edge part of the forging 3 is ensured, and the forging 3 and die scrapping caused by the fact that the forging 3 is adhered to the upper die 1 can be avoided.

According to an embodiment of the present invention, step S2 further includes:

s3, ejecting the forging piece 3 from the lower die 2 through the ejector rod 4;

and S4, performing heat treatment on the forging 3.

In this embodiment, the bottom of the lower die 2 has a through hole 22 communicated with the die cavity 21, the ejector rod 4 can enter the die cavity 21 through the through hole 22 to eject the forging 3 out of the die cavity 21, when the upper end of the ejector rod 4 is located at the through hole 22, the through hole 22 is just plugged, that is, the lower die 2 and the ejector rod 4 enclose the wall surface of the round table-shaped die cavity 21 together, so as to fix the forging 3, prevent the forging 3 from being dislocated under the condition of multiple forging, and cause the reinforcing ribs 31 to gnaw or fold the bottom.

According to an embodiment of the present invention, step S4 includes:

s41, primary annealing: heating the forging 3 to 945-955 ℃, preserving heat for 1-1.5 hours, and air-cooling;

s42, secondary annealing: and heating the forging 3 to 525-535 ℃, preserving heat for 6-6.5 hours, and air-cooling.

In the embodiment, the forging 3 is subjected to double annealing, the heating temperature of primary annealing is 950 ℃, the heat preservation is carried out for 1 hour, and air cooling is carried out; the heating temperature of the secondary annealing is 530 ℃, the heat preservation is carried out for 6 hours, and the air cooling is carried out. Thereby obtaining the forging 3 with room temperature performance and high temperature performance meeting the requirements.

According to an embodiment of the present invention, before step S1, the method further includes:

s01, sawing bars with preset volumes;

In this embodiment, when the calculation formula is performed on the preset volume of the bar, the deformation amount of greater than 50% during upsetting should be ensured to obtain better tissue performance.

According to an embodiment of the present invention, in step S01, the preset volume is a calculated volume obtained by adding 1.5mm to 2.5mm to the height direction of the bowl-shaped forging 3 with the reinforcing ribs 31. In the embodiment, after the original height direction of the bowl-shaped forging piece with the reinforcing ribs is increased by 2mm, the volume is calculated to obtain the preset volume, the preset volume is converted into the corresponding diameter and length of the bar, and the bar is sawed and cut through a sawing machine. When in blanking, the volume is converted after the height of the original forging piece 3 is increased by 2mm, so that the under-pressure quantity of closed die forging is reduced, and partial underfill caused by partial feeding unevenness is avoided.

According to one embodiment of the invention, in step S02, the cross-sectional area of the biscuit is greater than the end surface area of the carrier rod 4 and the diameter of the biscuit is 2mm to 5mm smaller than the diameter of the mould cavity 21. In this embodiment, the bar is heated, upset, the upsetting deformation is greater than 50%, the diameter of the formed cake blank is required to be placed on the platform 42 where the ejector rod 4 is located, and the diameter of the cake blank is 2mm to 5mm smaller than that of the lower die cavity 21. The phenomenon that one side of the forging piece 3 is not full due to the fact that the diameter is too small and the blank on the other side is too much to produce burrs due to the fact that the forging piece is placed incorrectly is avoided; or because the diameter is too large, the cake blank is blocked in the die cavity 21 of the lower die 2 and cannot fall on the ejector rod 4, so that the cake blank is placed incorrectly, and the material is not uniformly fed during forming, thereby influencing the final forming.

As shown in fig. 1, 2, 3 and 4, the forging forming mold provided by the embodiment of the invention comprises an upper mold 1 and a lower mold 2, wherein the upper mold 1 is configured with a protruding part 11, the protruding part 11 is provided with a forming groove 12 extending upwards from the lower end surface along the height direction thereof, the forming groove 12 is used for forming a reinforcing rib 31 of the forging 3, the lower mold 2 is configured with a mold cavity 21 matched with the protruding part 11, and the height of the protruding part 11 is smaller than the depth of the mold cavity 21.

The forging forming die provided by the embodiment of the invention is a forming die of a bowl-shaped forging with reinforcing ribs, wherein the inner cavity of the bowl-shaped forging with the reinforcing ribs is provided with the reinforcing ribs 31, the forming die is divided into an upper die 1 and a lower die 2, the upper die 1 is provided with a boss 11 in a round table shape, the surface of the boss 11 is provided with a longitudinal forming groove 12 for forming the reinforcing ribs 31, the lower die 2 is provided with a die cavity 21 in a round table shape for fixing the forging 3 to provide a forging space, and the forging 3 is prevented from being dislocated under the condition of multiple forging, so that the reinforcing ribs 31 are damaged or the bottom is folded. The bulge 11 of the upper die 1 is matched with the die cavity 21 of the lower die 2 to form closed precision die forging, so that the problems that in the prior art, a bowl-shaped forging rib with a reinforcing rib is not fully filled, the damage and folding defects are easily caused, the titanium alloy forging 3 is adhered to the upper die 1, the trimming process is saved, and the obtained streamline of the forging 3 is complete and has no cutting off are solved.

According to an embodiment provided by the invention, the forging forming die further comprises a push rod 4, a through hole 22 communicated with the die cavity 21 is formed in the bottom of the lower die 2, the push rod 4 can penetrate through the through hole 22 to enter the die cavity 21, and the end portion of the push rod 4 seals the through hole 22. In this embodiment, the bottom of the lower die 2 has a circular through hole 22 communicated with the die cavity 21, the ejector rod 4 can enter the die cavity 21 through the through hole 22 to eject the forging 3 out of the die cavity 21, when the upper end of the ejector rod 4 is located at the through hole 22, the through hole 22 is just plugged, after the forging 3 is molded, the ejector rod 4 moves upwards, so that the forging 3 can be ejected out of the die cavity 21, and the die taking is convenient.

According to one embodiment of the present invention, the ejector rod 4 includes a rod 41 and a platform 42, the platform 42 is connected to an end of the rod 41, and the platform 42 is matched with the through hole 22. In this embodiment, the cross-sectional area of the rod 41 is smaller than that of the platform 42, the platform 42 is used as the end of the ejector rod 4, the upper surface of the platform and the inner surface of the lower die 2 together form the wall surface of the die cavity 21, that is, the end surfaces of the lower die 2 and the ejector rod 4 enclose the wall surface of the truncated cone-shaped die cavity 21 together, so as to fix the forging 3, prevent the forging 3 from being dislocated under the condition of multiple forging and stamping, and cause the reinforcing ribs 31 to gnaw or fold the bottom. The platform 42 is completely matched with the through hole 22, so that no gap is generated, and the streamline integrity of the forging 3 can be ensured during forging.

According to one embodiment of the invention, the upper surface of the platform 42 is configured with a recess 43, the recess 43 being for the positioning block 32 corresponding to the bottom of the shaped forging 3. In this embodiment, the upper surface of the platform 42 is generally concave 43, that is, a semicircular positioning block 32 can be formed at the bottom of the forging 3 during forging, which plays a role in fixing the forging 3, so as to avoid the problem that the reinforcing ribs 31 are gnawed and the bottom surface is folded due to the dislocation of the forging 3 during multiple forging.

According to one embodiment of the present invention, the inner bottom surface of the lower mold 2 is configured with a bottom protrusion 23, the bottom protrusion 23 is used to form the bottom recess 33 of the forging 3, and the upper surface of the platform 42 is flush with the upper surface of the bottom protrusion 23. In this embodiment, an upward bottom protrusion 23 is configured on the bottom surface of the cavity 21 of the lower die 2, and during forging, an upward recess 43 may be formed at the bottom of the forging 3, where the upper surface of the platform 42 is flush with the upper surface of the bottom protrusion 23, and the recess 43 on the upper surface of the platform 42 is lower than the upper surface of the bottom protrusion 23.

According to one embodiment of the present invention, the draft angle of the upper die 1 is 17 ° and the draft angle of the lower die 2 is 17 ° and 3 °. In the embodiment, the problem that the forging piece 3 is adhered to the upper die 1 is solved by matching with the combination of different draft angles of the upper die 117 DEG and the lower die 217 DEG and 3 deg. Meanwhile, redundant metal generated by burrs is saved, a set of trimming tool and trimming working procedures are saved, and the streamline integrity of the edge part of the forging piece 3 is ensured.

According to one embodiment of the present invention, the number of the molding grooves 12 is 6, and the molding grooves are uniformly distributed on the protruding portion 11 along the circumferential direction. In this embodiment, the height dimension of the bowl-shaped forging 3 with the reinforcing ribs 31 to be forged is 70mm, and the inner cavity is provided with 6 reinforcing ribs 31, so that 6 forming grooves 12 are formed. In other embodiments, the number and distribution of the forming slots 12 may be selected according to actual needs.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A forging forming method is characterized in that: comprising the following steps:

s1, preprocessing a blank, an upper die and a lower die; heating the cake blank to 20-50 ℃ below the phase transition point, and preserving heat for 90-120 min to form the blank;

s2, placing the blank into a die cavity of the lower die, wherein the upper die is provided with a boss-shaped protruding part in a truncated cone shape, a longitudinal forming groove is formed in the surface of the protruding part, the blank is forged and pressed for multiple times through the protruding part of the upper die until the upper die is contacted with the lower die, and the blank is formed into a bowl-shaped forging with reinforcing ribs;

the step S2 further comprises the following steps:

s3, ejecting the forging from the lower die through an ejector rod;

s4, carrying out heat treatment on the forging;

the step S4 includes:

2. The forging forming method as recited in claim 1, wherein: the step S1 comprises the following steps: preheating the upper die and the lower die, wherein the preheating temperature is 200-250 ℃.

3. The forging forming method as recited in claim 2, wherein: in step S1, the cake blank is uniformly coated with a glass lubricant before being heated.

4. The forging forming method as recited in claim 1, wherein: in step S2, after the blank is placed in the cavity of the lower die, a sheet-like solid graphite powder is coated on the upper surface of the blank.

5. The forging forming method as recited in claim 4, wherein: in step S2, the surface of the boss of the upper mold is coated with a water-based graphite lubricant.

6. The forging forming method as recited in claim 1, wherein: the step S1 is preceded by the following steps:

s01, sawing bars with preset volumes;

7. The forging forming method as recited in claim 6, wherein: in step S01, the preset volume is a calculated volume obtained by adding 1.5 mm-2.5 mm to the height direction of the bowl-shaped forging with the reinforcing ribs.

8. The forging forming method as recited in claim 6, wherein: in step S02, the cross-sectional area of the cake blank is larger than the end surface area of the ejector rod, and the diameter of the cake blank is 2 mm-5 mm smaller than the diameter of the die cavity.