CN115815515A

CN115815515A - Forging method for improving uniform structure of GH 4169-series high-temperature alloy annular die forging

Info

Publication number: CN115815515A
Application number: CN202211588987.4A
Authority: CN
Inventors: 朱娟娟; 和磊; 苏灵锐; 黄大卫
Original assignee: Shaanxi Hongyuan Aviation Forging Co Ltd
Current assignee: Shaanxi Hongyuan Aviation Forging Co Ltd
Priority date: 2022-12-09
Filing date: 2022-12-09
Publication date: 2023-03-21

Abstract

The invention belongs to the field of forging hot working, and relates to a forging method for improving the uniform structure of a GH4169 series high-temperature alloy annular die forging. The method comprises the steps of obtaining a ring blank with a uniform structure by controlling blank-making heating temperature and forging deformation, and then performing pre-forging, wherein the design purpose of a pre-forging die is to distribute the deformation of each part in advance, so that the deformation of each part of the part meets the requirement of 30-70% during finish forging, no deformation dead zone or critical deformation zone exists, and the structure of each part of the part is uniform. The pre-forging and the final forging are forged in a soft packing manner, so that the temperature of the blank is prevented from being reduced too fast, and the forging cold die structure is reduced.

Description

Forging method for improving uniform structure of GH 4169-series high-temperature alloy annular die forging

Technical Field

The invention belongs to the field of forging hot working, and relates to a forging method for improving the uniform structure of a GH4169 series high-temperature alloy annular die forging.

Background

The GH4169 series high-temperature alloy is the most widely used alloy on an aeroengine and is mainly used for combustion chamber parts, and the requirements on the structure and the performance of the parts are very strict because the alloy works under the conditions of high temperature and high pressure for a long time. The annular die forging piece is simple in structure, in conventional forging, cake blank forging forming is adopted, the center hole is formed by die forging connected leather, or the annular blank is directly die forged into a final forging piece. Therefore, the influence of the forging process on the structural uniformity of the forged piece is researched, the grain size is controlled, and the method has very important significance for improving the performance of the annular die forged piece.

Disclosure of Invention

The purpose of the invention is as follows: the forging method for improving the uniformity of the structure of the GH4169 high-temperature alloy annular die forging is provided, the uniformity of the structure of the GH4169 high-temperature alloy annular die forging is improved, the GH4169 high-temperature alloy annular die forging meets standard requirements, and the good and stable performance of each part of a part is further ensured.

The technical scheme is as follows:

a forging method for improving the uniform structure of a GH4169 series high-temperature alloy annular die forging comprises the following steps:

step 1: manufacturing two sets of dies, wherein one set of dies is a finish forging die, the other set of dies is a pre-forging die, and the materials of the dies are 5CrNiMo; the cavity of the pre-forging die is a circular ring, and the upper end face and the lower end face of the cavity are both gradually inclined upwards from inside to outside;

step 2: performing blank making and one-time forging: heating a specification blanking GH4169 bar in an electric furnace to a forging temperature of 980-1020 ℃, preserving heat until the bar is thoroughly heated, preheating a free forging hammer anvil to be more than or equal to 150 ℃, completing upsetting deformation of a first deformation on the free forging hammer, completing blank making and one-heat forging through rounding and punching, air cooling to room temperature, adding an inner hole to a required size, and removing burrs and defects of the inner hole to obtain a first ring blank;

and step 3: performing blank making and two-fire forging: heating the first ring blank in an electric furnace to a forging temperature of 980-1020 ℃, preserving heat until the first ring blank is completely hot, preheating a free forging hammer anvil to be more than or equal to 150 ℃, placing the blank on a trestle reaming tool, enlarging the size of an inner hole through the free forging hammer to obtain a second ring blank, performing air cooling to room temperature, wherein the deformation of the trestle reaming ring blank is a second deformation which is less than the first deformation;

and 4, step 4: and (3) performing pre-forging on the second ring blank by using a pre-forging die: preheating a pre-forging die to be more than or equal to 250 ℃, heating the second ring blank in an electric furnace to the forging temperature of 980-1020 ℃ and preserving heat until the second ring blank is thoroughly hot, taking the second ring blank out of the furnace after the second ring blank is thoroughly hot and soft covering the second ring blank by adopting a heat preservation material with a proper size, after the second ring blank is re-heated and preserved heat for 0.5-1h, forging the second ring blank by adopting a counter hammer in the pre-forging die, performing single-shot forming, wherein the interval time of each hammer is 2-5s, the forging deformation is the third deformation, performing air cooling to room temperature after forging, and removing burrs by adopting a water cutting mode to obtain a pre-forging piece;

and 5: and (3) performing finish forging on the pre-forged piece by using a finish forging die: preheating a pre-forging die to be more than or equal to 250 ℃, heating the pre-forging blank in an electric furnace to a forging temperature of 980-1010 ℃ and preserving heat until the pre-forging blank is thoroughly hot, discharging the blank out of the furnace after the thorough heat is thoroughly hot, soft covering the blank by adopting a heat preservation material with a proper size, returning the blank to the furnace and preserving heat for 0.5-1h, forging by adopting a pair of hammers in a finish forging die, performing single-shot forming by the first 5 hammers, performing single-shot forming at an interval of 3-5s every hammer, continuing the subsequent single-shot forming at an interval of 2-4s every hammer, wherein the forging deformation is a fourth deformation which is more than a third deformation, controlling the finish forging temperature to be more than or equal to 910 ℃, performing air cooling to room temperature after forging, and removing burrs by adopting a water cutting mode to obtain the final forging piece.

Further, in step 1, the inclination angles of the upper end surface and the lower end surface of the pre-forging die cavity are 10-20 °.

Further, in step 1, the upper and lower end surfaces of the pre-forging die cavity are curved surfaces.

Further, the first deformation amount is 30% to 60%.

Further, the second deformation amount is 25% -40%.

Further, the third deformation amount is 20% to 30%.

Further, the fourth deformation amount is 30% to 70%.

Furthermore, the forging equipment in the pre-forging and die forging processes is a 400KJ counter-blow hammer, and the air pressure of the equipment is 0.6-0.5Mpa.

Has the advantages that:

the forging method for improving the uniform structure of the GH4169 series high-temperature alloy annular die forging piece obtains an annular blank with a uniform structure by controlling the heating temperature and the forging deformation of a blank, and then carries out pre-forging, wherein the design purpose of a pre-forging die is to distribute the deformation of each part in advance so that the deformation of each part of the part meets the requirement of 30-70% during finish forging, and no deformation dead zone or critical deformation zone exists so that the structure of each part of the part is uniform. The pre-forging and the final forging are forged in a soft sleeve mode, so that the temperature of a blank is prevented from being reduced too fast, and the forging cold die structure is reduced; when the hammer is subjected to pre-forging and final forging, the hammering rhythm and interval time are controlled, pre-forging and single-click forming are carried out, the forging deformation is more than or equal to 20% at the interval time of each hammer, the former 5-click forming is required for the final forging, the interval time of each hammer is 3-5s, subsequent single-click forming is carried out continuously, the interval time of each hammer is 2-4s, the forging deformation is 25% -60%, and the final forging temperature is controlled to be more than or equal to 910 ℃. The GH4169 series high-temperature alloy annular die forging forged by the process has uniform structure, excellent and stable mechanical property and meets the requirement of aviation standard.

Drawings

FIG. 1 is a schematic view of a finish forged seal ring for an engine according to example 1;

FIG. 2 is a schematic view of a seal ring preforging for an engine in example 1.

Detailed Description

A forging method for improving the uniform structure of a GH4169 series high-temperature alloy annular die forging piece comprises the following steps:

step 1: manufacturing two sets of dies, wherein one set of dies is a finish forging die, the other set of dies is a pre-forging die, and the materials of the dies are 5CrNiMo; the cavity of the pre-forging die is a circular ring, and the upper end face and the lower end face of the cavity are both gradually inclined upwards from inside to outside; if the conventional ring blank is directly subjected to finish forging, the deformation direction of the ring blank at the protruding positions of the upper die and the lower die is vertical translation and basically has no deformation, and the part forms a deformation dead zone, so that the crystal grains are coarse and the performance is reduced. In order to achieve an overall uniform structure, the deformation is the greatest weight, and the upper end face and the lower end face of the pre-forging die cavity are both inclined upwards gradually from inside to outside in order to be opposite to the deformation direction during finish forging and increase the deformation at the position during finish forging. The relationship between the inclination angles of the upper and lower end surfaces of the preforging die and the finish forging deformation is as follows:

step 2: performing blank making and one-time forging: heating a specification blanking GH4169 bar in an electric furnace to a forging temperature of 980-1020 ℃, preserving heat until the bar is thoroughly heated, preheating a free forging hammer anvil to be more than or equal to 150 ℃, completing upsetting deformation with the deformation of 30-60% on the free forging hammer, completing blank manufacturing and one-heat forging through rounding and punching, air cooling to room temperature, mechanically adding an inner hole to a required size, and removing burrs and defects of the inner hole to obtain a first ring blank;

and step 3: performing blank making and two-fire forging: heating the first ring blank in an electric furnace to a forging temperature of 980-1020 ℃, preserving heat until the first ring blank is completely hot, preheating a free forging hammer anvil to be more than or equal to 150 ℃, placing the blank on a trestle reaming tool, enlarging the size of an inner hole through a free forging hammer to obtain a second ring blank, wherein the deformation of the trestle reaming ring blank is 25-40%, and air-cooling to room temperature; the saddle reamed holes are mainly formed by local forging and rotation along the radial direction, dynamic recrystallization occurs in the metal within the range of 25-40% of deformation, the degree of recrystallization is sufficient, and good equiaxial grains can be obtained.

And 4, step 4: and (3) performing pre-forging on the second ring blank by using a pre-forging die: preheating a pre-forging die to be more than or equal to 250 ℃, heating the second ring blank in an electric furnace to the forging temperature of 980-1020 ℃ and preserving heat until the second ring blank is thoroughly hot, taking the second ring blank out of the furnace after the second ring blank is thoroughly hot and soft covering the second ring blank by adopting a heat preservation material with a proper size, after the second ring blank is re-heated and preserved heat for 0.5-1h, forging the second ring blank by adopting a counter hammer in the pre-forging die, performing single-shot forming, wherein the interval time of each hammer is 2-5s, the forging deformation is 20-30%, performing air cooling to room temperature after forging, and removing burrs by adopting a water cutting mode to obtain a pre-forging piece;

and 5: and (3) performing finish forging on the pre-forged piece by using a finish forging die: preheating a pre-forging die to be more than or equal to 250 ℃, heating the pre-forging blank in an electric furnace to a forging temperature of 980-1010 ℃ and preserving heat to be thorough, discharging from the furnace after thorough heat preservation and carrying out soft covering by adopting a heat preservation material with a proper size, returning to the furnace and preserving heat for 0.5-1h, forging by adopting a pair of hammers in a finish forging die, carrying out single-shot forming on the first 5 hammers, wherein the interval time of each hammer is 3-5s, subsequently continuing the single-shot forming, the interval time of each hammer is 2-4s, the forging deformation is 30-70%, the finish forging temperature is controlled to be more than or equal to 910 ℃, carrying out air cooling to room temperature after forging, and removing burrs by adopting a water cutting mode to obtain a final forging piece; the hot forging is carried out on the blank by adopting a counter-blow hammer, the deformation rate of the counter-blow hammer is high, the temperature rise of the core part of the blank caused by deformation is high, the front 5 hammers are formed by single-blow, the interval of each hammer is 3-5s, so that the deformation heat and the deformation energy generated after the single-blow deformation of each hammer are beneficial to the transmission and the dissipation of the deformation heat in the time of 3-5s, the recrystallization can be rapidly completed by part of the deformation heat and the deformation energy, the internal temperature of the blank is controlled, and the coarse grains caused by the overhigh temperature rise are prevented. After hammering 5 hammers, the heat effect of the whole temperature loss of the blank caused by deformation is reduced, at the moment, the blank continues to be clicked, the interval time is shortened by 2-4s, the final forming of the blank is completed within the final forging temperature range, the purpose of obtaining fully recrystallized equiaxial grains and uniform die forging structure is achieved.

The present invention will be described in further detail with reference to specific examples.

Example 1:

as shown in figure 1, the forging piece of the inner cone front sealing ring for an engine is made of GH4169, the weight of the forging piece is 67Kg, the contour dimension of the forging piece is phi 370 multiplied by 106mm, and GH4169 rods with phi 250 multiplied by 230mm are selected.

Firstly, heating a bar with the diameter of 250 multiplied by 230mm in an electric furnace to the forging temperature of 1020 ℃ and preserving heat for 140min, upsetting the bar on a free forging hammer to the diameter of 320 multiplied by 140mm, then finishing blank manufacturing through rounding and punching, forging with fire, air cooling to the room temperature, and mechanically adding an inner hole to the required size to obtain a ring blank with the diameter of 330 multiplied by 140 mm; the hammer anvil is preheated to 250 ℃ in the forging process, and the forging equipment is a 3T free forging hammer.

Heating the ring blank in an electric furnace to a forging temperature of 1010 ℃ and preserving heat for 70min, placing the blank on a trestle reaming tool, expanding the size of an inner hole by a free forging hammer to obtain a ring blank with phi 380 multiplied by phi 213 multiplied by 135mm, and air-cooling to room temperature; the hammer anvil is preheated to 250 ℃ in the forging process, and the forging equipment is a 3T free forging hammer.

Heating the ring blank in an electric furnace to a forging temperature of 1010 ℃ and preserving heat for 55min, discharging the ring blank out of the electric furnace, soft covering the ring blank by adopting a heat preservation material, returning the ring blank to the electric furnace and preserving heat for 0.5h, placing the ring blank into a pre-forging die for pre-forging, wherein the hammering times are 8-10 hammers, the interval of each hammer is-3 s, and air cooling to room temperature after forging; preheating a used pre-forging die to 300 ℃, and forging equipment: 400KJ counter-blow hammer and the wind pressure of the equipment is 0.6-0.5Mpa.

Machining an inner hole and burrs of the obtained pre-forged piece, polishing and removing defects, heating the pre-forged piece in an electric furnace to a forging temperature of 1000 ℃, keeping the temperature for 50min, taking out the pre-forged piece from the electric furnace, soft covering the pre-forged piece by adopting a heat-insulating material, returning the pre-forged piece to the electric furnace, keeping the temperature for 0.5h, taking out the pre-forged piece from the electric furnace, putting the pre-forged piece into a finish forging die for pre-forging, wherein the hammering times are 10-12 hammers, the interval of each hammer of the first five hammers is-4 s, the interval of each hammer of the subsequent hammers is-2 s, and air-cooling the pre-forged piece to room temperature; preheating a finish forging die to 300 ℃, and forging equipment: 400KJ counter-blow hammer, the wind pressure of the equipment is 0.6-0.5Mpa.

Subsequently, machining internal control burrs and burrs by adopting a water cutting mode to obtain a final forged piece; the forging produced by the process has uniform macrostructure through the manager chemical detection, the average grain size of each part is 6 grades, the standard requirement is met and is more than or equal to 4 grades, and the room-temperature mechanical property, the high-temperature tensile property, the durability and the hardness of the GH4169 ring forging completely meet the requirements.

Claims

1. A forging method for improving the uniformity of a structure of a GH4169 high-temperature alloy annular die forging is characterized by comprising the following steps of:

step 1: manufacturing two sets of dies, wherein one set of dies is a finish forging die, the other set of dies is a pre-forging die, and the materials of the dies are 5CrNiMo; the cavity of the preforging die is a circular ring, and the upper end face and the lower end face of the cavity are both inclined upwards gradually from inside to outside;

step 2: performing blank making and one-time forging: heating a specification blanked GH4169 bar material in an electric furnace to a forging temperature of 980-1020 ℃, preserving heat until the bar material is thoroughly heated, preheating a free forging hammer anvil to be more than or equal to 150 ℃, completing upsetting deformation of a first deformation amount on the free forging hammer, completing blank making one-fire forging through rounding and punching, air cooling to room temperature, mechanically adding an inner hole to a required size, and removing inner hole burrs and defects to obtain a first ring blank;

and step 3: performing blank making and two-fire forging: heating the first ring blank in an electric furnace to a forging temperature of 980-1020 ℃, preserving heat until the first ring blank is completely hot, preheating a free forging hammer anvil to be more than or equal to 150 ℃, placing the blank on a trestle reaming tool, enlarging the size of an inner hole through the free forging hammer to obtain a second ring blank, performing air cooling to room temperature, wherein the deformation of the trestle reaming ring blank is a second deformation, and the second deformation is less than the first deformation;

2. The forging method for improving the uniform structure of the GH4169 series high-temperature alloy annular die forging according to claim 1, wherein in the step 1, the inclination angles of the upper end face and the lower end face of the pre-forging die cavity are 10-20 degrees.

3. The forging method for improving the uniform structure of the GH4169 high-temperature alloy annular die forging according to claim 1, wherein in the step 1, the upper end face and the lower end face of the pre-forging die cavity are curved.

4. The forging method for improving the uniformity of the structure of the GH4169 high-temperature alloy annular die forging according to claim 1, wherein the first deformation is 30-60%.

5. The forging method for improving the uniformity of the structure of the GH4169 high-temperature alloy annular die forging according to claim 1, wherein the second deformation is 25-40%.

6. The forging method for improving the uniformity of the structure of the GH4169 high-temperature alloy annular die forging according to claim 1, wherein the third deformation is 20-30%.

7. The forging method for improving the uniform structure of the GH4169 series high-temperature alloy annular die forging according to claim 1, wherein the fourth deformation amount is 30-70%.

8. The forging method for improving the uniform structure of the GH4169 series high-temperature alloy annular die forging piece according to claim 1, wherein the forging equipment for the pre-forging and die forging processes is a 400KJ counter-blow hammer, and the air pressure of the equipment is 0.6-0.5MPa.