CN111215567A

CN111215567A - Forging method for improving grain size of GH4099 high-temperature alloy thin-wall ring

Info

Publication number: CN111215567A
Application number: CN201911241067.3A
Authority: CN
Inventors: 武茜宝; 姚彦军; 邹龙龙
Original assignee: Shaanxi Hongyuan Aviation Forging Co Ltd
Current assignee: Shaanxi Hongyuan Aviation Forging Co Ltd
Priority date: 2019-12-06
Filing date: 2019-12-06
Publication date: 2020-06-02

Abstract

The invention relates to a forging method for improving the grain size of a GH4099 high-temperature alloy thin-wall ring piece, which is characterized by comprising the following steps: the method comprises the steps of primary ring blank forming, ring rolling forming and heat treatment, wherein the ring rolling forming step comprises the following steps: heating the primary ring blank in an electric furnace to a forging temperature of 1080-1110 ℃, putting the primary ring blank on a ring rolling mill for rolling and forming, wherein end rolling equipment is adopted in the rolling process, and the deformation of the primary ring blank is 27-42%, so that the ring forging is obtained. The end rolling equipment is characterized in that conical roller equipment is added in the reaming process to control the increase of the height direction size of the ring piece, so that the height direction size of the ring piece is within the tolerance range of the forge piece. According to the rolling forming method of the GH4099 high-temperature alloy thin-wall type ring forging, the high-temperature alloy ring forging with excellent thin-wall type structure performance can be obtained by controlling the forging heating temperature, the forging starting temperature, the finish forging temperature and the forging deformation.

Description

Forging method for improving grain size of GH4099 high-temperature alloy thin-wall ring

Technical Field

The invention belongs to the technical field of forging, and relates to a forging method for improving the grain size of a GH4099 high-temperature alloy material.

Background

GH4099 is a high-alloying nickel-based aging plate alloy, which is comprehensively strengthened by cobalt, tungsten, molybdenum, aluminum and titanium elements, so that the alloy has higher heat strength, can be used for a long time below 900 ℃, and has the maximum working temperature of 1000 ℃. The alloy has stable structure and satisfactory cold and hot processing forming and welding process performance, thereby being widely applied to large plate structural members.

GH4099 can be used as it is without aging treatment after solution treatment. The heating of the forging and the control of the forming process are difficult points of the forging of the material, and have important influence on the internal structure and the performance. The grain size of the forging piece also influences the welding performance of the material, so that the grain size level of the forging piece is controlled, and the tendency of generating cracks on the surface of the material in the welding process can be effectively reduced.

The GH4099 high-temperature alloy is heated to 1140 ℃ by a natural gas furnace, a prefabricated blank is produced by a free forging hammer, after the surface quality of a forged piece is checked by cooling, the prefabricated blank is heated to 1140 ℃ and then is rolled on a ring rolling machine to obtain a ring product, the physical and chemical properties are checked, the data is in a standard range, but the margin is not large, the grain size of the forged piece is checked, and the result is 2-3 grade, the grain structure is large, and the performance of the forged piece is influenced to a certain extent. The microstructure of the forging is sensitive to the influence of temperature, and the uniformity of the microstructure can also be realized by controlling the heating temperature and the heat preservation time of forging and increasing the deformation of forging.

Reducing the forging heating temperature can effectively reduce the growth rate of the internal structure of the blank in the heating and heat preservation process, but the reduction of the temperature can increase the tendency of forging cracks, and under the condition of ensuring less damage, the grain size level after forging can reach more than 4.5 grade by reducing the forging temperature. Therefore, the key problem of forging the GH4099 superalloy ring-rolled forgings is to accurately control the forging temperature and process and obtain the expected structure.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the deformation performance of the GH4099 high-temperature alloy material is improved under the action of multidirectional compressive stress, forging cracks of the forging caused by low temperature and multidirectional stress are avoided, and the hole expanding method with stable and uniform forging structure is obtained. The stable physical and chemical performance is obtained, and the structure reliability of the GH4099 superalloy component is improved.

The technical scheme adopted by the invention is a forging method for improving the grain size of a GH4099 high-temperature alloy thin-wall ring piece, which comprises the following steps:

1. one-step ring blank forming

Heating a specification blanking GH4099 bar to a forging temperature of 1100-1140 ℃, upsetting, punching, machining an inner hole on a free forging hammer to remove inner hole burrs and defects, and expanding the size of the inner hole on a prefabricated blank on a horse device through the free forging hammer to obtain a primary ring blank;

2. ring rolling and expanding forming

Heating the primary ring blank in an electric furnace to a forging temperature of 1080-1110 ℃, then putting the primary ring blank on a ring rolling mill for rolling and forming, wherein an end rolling technology is adopted in the rolling process, the deformation is 27% -42%, and a ring forging is obtained. The end rolling technology is characterized in that a conical roller is added in the reaming process to control the increase of the height direction size of the ring piece, so that the height direction size of the ring piece is within the allowable tolerance range of a forged piece.

3. Thermal treatment

And (3) carrying out solution heat treatment on the GH4099 ring forging, wherein the solution treatment is to heat the GH4099 ring forging to 1080-1100 ℃, water-cool the GH4099 ring forging for 30 minutes, fish out the GH4099 ring forging, and air-cool the GH4099 ring forging to room temperature.

Further, in the step 1, a 3t free forging hammer is used for producing 20 Kg-60 Kg of blank, and the process is completed by 2-4 fires.

Further, in step 2, thermocouple strip temperature measurement is adopted for furnace temperature control, and feedback control is performed.

Further, in steps 1 and 2, the equipment, the tool and the used tool are preheated to 200-300 ℃.

Further, in the step 2, a forged piece with the final wall thickness of the ring piece of 20-40 mm can be formed, and the height dimension of the ring piece is controlled within the tolerance range required by the forged piece by applying an end rolling technology.

The invention has the beneficial effects that: according to the rolling forming method of the GH4099 high-temperature alloy thin-wall type ring forging, the high-temperature alloy ring forging with excellent thin-wall type structure performance can be obtained by controlling the forging heating temperature, the forging starting temperature, the finish forging temperature and the forging deformation.

Detailed Description

The main chemical element contents (weight percentage) of the GH4099 superalloy are as follows: content of C: less than or equal to 0.08, Cr content: 17% -20%, Co content: 5% -8%, W content: 5-7%, Mo content: 3.5% -4.5%, Al content: 1.7-2.4%, Ti content: 1.0% -1.5%, Fe content: less than or equal to 2 percent, Mn content: less than or equal to 0.4 percent, Si content: less than or equal to 0.5 percent, P content: less than or equal to 0.015 percent, and the balance: ni

Heating a specification blanking GH4099 bar to a forging temperature of 1100-1140 ℃, putting the bar on a hammer anvil of a 3t free forging hammer, upsetting, punching, mechanically turning an inner hole to remove inner hole burrs and defects, and expanding the size of the inner hole on a pre-forming blank on a horse device through a free forging hammer to obtain a primary ring blank; and heating the primary ring blank in an electric furnace to a forging temperature of 1080-1110 ℃, putting the primary ring blank on a ring rolling mill for rolling and forming, wherein an end rolling technology is adopted in the rolling process, and the deformation amount is 27% -42%, so that the ring forging is obtained. The end rolling equipment is characterized in that a conical roller is added in the reaming process to control the increase of the height direction size of the ring piece, so that the height direction size of the ring piece is within the allowable tolerance range of the forged piece. And (3) carrying out solution heat treatment on the GH4099 ring forging, wherein the solution treatment is to heat the GH4099 ring forging to 1080-1100 ℃, water-cool the GH4099 ring forging for 30 minutes, fish out the GH4099 ring forging, and air-cool the GH4099 ring forging to room temperature.

Through visual inspection, the surface of the GH4099 ring forging is smooth and has visual microcracks, and the GH4099 ring forging can be removed after being polished by a wind grinding wheel, so that the dimension meets the requirement; through detection, the room-temperature mechanical property, the high-temperature tensile property, the durability and the hardness of the GH4099 ring forging completely meet the requirements; through detection, the macrostructure of the GH4099 ring forging is uniform; and the grain size of the GH4099 ring forging is detected to be 5 grade.

Claims

1. The forging method for improving the grain size of the GH4099 high-temperature alloy thin-wall ring is characterized by comprising the following steps of: the method comprises the steps of primary ring blank forming, ring rolling forming and heat treatment, wherein the ring rolling forming step comprises the following steps: heating the primary ring blank in an electric furnace to a forging temperature of 1080-1110 ℃, putting the primary ring blank on a ring rolling mill for rolling and forming, wherein end rolling equipment is adopted in the rolling process, and the deformation of the end rolling equipment is 27-42%, so that a ring forging is obtained; the end rolling equipment is characterized in that a conical roller is added in the reaming process to control the increase of the height direction size of the ring piece, so that the height direction size of the ring piece is within the allowable tolerance range of the forged piece.

2. The forging method as recited in claim 1, wherein the heat treatment step is: and carrying out solution heat treatment on the GH4099 ring forging.

3. The heat treatment method of claim 2, wherein the solution heat treatment is to heat the GH4099 ring forging to 1080-1100 ℃, water cool for 30 minutes, fish out, air cool to room temperature.

4. The forging method as recited in claim 1, wherein the primary ring blank forming step is: the method comprises the steps of heating a specification blanking GH4099 bar to a forging temperature of 1100-1140 ℃, upsetting, punching, machining an inner hole on a free forging hammer to remove inner hole burrs and defects, and expanding the size of the inner hole on a prefabricated blank on a horse device through the free forging hammer to obtain a primary ring blank.

5. The forging method as recited in claim 4, wherein: in the primary ring blank forming step, 20 Kg-60 Kg of GH4099 blank is forged by a 3t free forging hammer over 2-4 fires.

6. The forging method as recited in claim 1, wherein: in the step of forming the ring rolled piece, the furnace temperature is controlled by adopting thermocouple strip material for temperature measurement, and feedback control is carried out.

7. The forging method as recited in claim 1, wherein: the method as claimed in claim 1, wherein the equipment, the tool and the tools are preheated to 200-300 ℃ in the steps of one-time ring blank forming and ring rolling forming.

8. The method of claim 1, wherein: in the step of ring rolling and expanding, a forged piece with the final wall thickness of the ring piece of 20-40 mm can be formed, and meanwhile, the height dimension of the ring piece is controlled within the tolerance range required by the forged piece by using end rolling equipment.