CN112143872B

CN112143872B - Turbine disc gradient temperature field regulation and control device and method

Info

Publication number: CN112143872B
Application number: CN202010970728.2A
Authority: CN
Inventors: 罗皎; 李聪; 李淼泉
Original assignee: Northwestern Polytechnical University
Current assignee: Northwestern Polytechnical University
Priority date: 2020-09-16
Filing date: 2020-09-16
Publication date: 2022-05-13
Anticipated expiration: 2040-09-16
Also published as: CN112143872A

Abstract

The invention relates to a gradient heat treatment process or gradient temperature field regulation and control device and method. Aiming at the problem that the temperature gradient in the literature gradient heat treatment process can not be freely regulated, the technical scheme of the invention is as follows: by designing a gradient heat treatment device with a cavity and capable of freely adding auxiliary heat storage blocks and combining a finite element numerical simulation technology, the trend of the temperature field on the turbine disc and the trend of the grain size distribution along with the change of time is predicted, the influence rule of different auxiliary heat storage blocks on the temperature gradient and the grain size distribution is obtained, a relation database of the shape and the size of a tool, the temperature in the furnace and the gradient temperature field of the turbine disc is established, and a temperature gradient free regulation and control method under the target grain size distribution of the turbine disc is developed. The invention has the outstanding advantages that the temperature rise rate at the disc center and the temperature gradient of the disc body are freely regulated, the problem that a heat storage die needs to be redesigned when the size of the disc changes is avoided, and the design and manufacturing cost of the gradient heat treatment tool is reduced.

Description

Turbine disc gradient temperature field regulation and control device and method

Technical Field

The invention relates to a heat treatment process or method, in particular to a gradient heat treatment process or a gradient temperature field regulating and controlling method, and particularly relates to a turbine disc gradient temperature field regulating and controlling device and a turbine disc gradient temperature field regulating and controlling method.

Background

The gradient heat treatment process is a heat treatment technology for obtaining a dual-performance metal part by controlling the temperature of different areas on special heat treatment equipment to enable the grain size after heat treatment to be in gradient change, and the technical key lies in accurate prediction and stable regulation and control of a gradient temperature field in the heat treatment process.

The U.S. patent publication No. US 6660110B1 discloses a gradient heat treatment apparatus and a gradient temperature field regulating method for a superalloy dual-performance disk, which is shown in fig. 1. The gradient heat treatment device comprises a first heat storage block 11, a second heat storage block 12, a first accommodating shell 13, a second accommodating shell 14, a base 15 and a heat insulation material 16, wherein a turbine disc to be treated is positioned between the first accommodating shell and the second accommodating shell, the base is connected with the second accommodating shell, and the first accommodating shell and the second accommodating shell are tightly filled with heat insulation cotton. The first heat storage block 11 and the second heat storage block 12 are respectively in contact with the central area of the disc 17, the heat storage blocks are isolated from a high-temperature environment through heat insulation materials and a containing shell, and the heat storage blocks absorb heat from the central area of the disc, so that the temperature of the central area is lower; the edge of the disc is exposed to the high temperature environment of the heat treatment furnace, and the temperature of the edge is higher. Through the gradient heat treatment device, the temperature gradient of over 200 ℃ can be formed between the disk center and the disk edge, and the temperature field of the transition region has no temperature mutation, thereby laying a foundation for orderly regulating and controlling the grain size after gradient heat treatment. However, the shape and size of the heat storage block in the device are fixed and unchangeable, free regulation and control of the temperature rise rate at the disc center cannot be realized, and steady and free regulation and control of the temperature gradient cannot be realized, so that the problem that the heat storage block needs to be redesigned when the size of a disc piece changes is caused, the design and manufacturing cost is greatly improved, and the problem of raw material waste is caused.

Disclosure of Invention

The technical problem solved by the invention is as follows: in order to overcome the defect that the conventional gradient heat treatment device can only obtain a gradient temperature field but cannot realize free regulation and control of the temperature gradient, the invention provides a turbine disc gradient temperature field regulation and control method based on the shape and size design of a tool.

The technical scheme of the invention is as follows: a turbine disc gradient temperature field regulating device comprises an upper containing shell, a lower containing shell, a base and heat insulation cotton, wherein a turbine disc to be treated is positioned between the upper containing shell and the lower containing shell and is coaxially arranged; the base is connected with the lower containing shell; the heat storage device is characterized by also comprising an upper heat storage mould, a first lower heat storage mould part, a second lower heat storage mould part and an auxiliary heat storage block; the upper heat storage mould is positioned in the upper containing shell, and heat insulation cotton is filled between the upper heat storage mould and the upper containing shell; the first lower heat storage mold component and the second lower heat storage mold component are positioned in the lower containing shell, heat insulation cotton is filled between the first lower heat storage mold component and the lower containing shell, and heat insulation cotton is filled between the second lower heat storage mold component and the lower containing shell; one end of the second lower heat storage mold part is connected with the lower containing shell, and the other end of the second lower heat storage mold part is connected with the first lower heat storage mold part; the upper containing shell, the lower containing shell, the upper heat storage mould of the base, the first lower heat storage mould part and the second lower heat storage mould part are coaxially arranged; a plurality of auxiliary heat storage blocks are arranged in the heat storage die part, and the turbine disc gradient temperature field can be freely regulated and controlled by arranging different numbers to form different shapes.

The further technical scheme of the invention is as follows: the upper containing shell is integrally a cylindrical body, the interior of the upper containing shell is a cavity, one end of the upper containing shell is open, the other end of the upper containing shell is closed, and the open end of the upper containing shell is in contact with a turbine disc to be processed; ear-shaped bulges parallel to the ground are arranged on two sides of the closed end and used for quick disassembly; the end face of the closed end is provided with a blind hole, and the center is provided with a through hole.

The further technical scheme of the invention is as follows: the whole upper heat storage die is in a convex shape, one end of the upper heat storage die is open, the other end of the upper heat storage die is closed, the open end of the upper heat storage die is fixedly connected with the closed end of the upper containing shell, and the convex end of the upper heat storage die is in contact with the center of the turbine disc to be processed.

The further technical scheme of the invention is as follows: and a plurality of auxiliary heat storage blocks and heat insulation cotton are placed in a cavity between the upper containing shell and the upper heat storage mold.

The further technical scheme of the invention is as follows: the first lower heat storage die part is provided with a through hole along the center, an annular groove is formed at one end of the first lower heat storage die part, and blind holes are symmetrically formed at the other end of the first lower heat storage die part along the central shaft.

The further technical scheme of the invention is as follows: the second lower heat storage mould component is provided with a through hole along the axis, and one end of the second lower heat storage mould component is provided with an annular bulge which is matched with the annular groove on the first lower heat storage mould component; the other end is provided with a plurality of cylindrical bulges along the circumferential direction of the axis.

The further technical scheme of the invention is as follows: one end of the first lower heat storage mold part is in contact with the turbine disc to be processed, the other end of the first lower heat storage mold part is connected with the second lower heat storage mold part to form a cavity after connection, and a plurality of auxiliary heat storage blocks and heat insulation cotton are placed in the cavity.

The further technical scheme of the invention is as follows: one end of the lower containing shell is open and the other end is closed, the closed end is axially provided with a through hole, and the end face of the closed end is uniformly provided with a plurality of circular pits along the circumferential direction of the axis and is matched with a plurality of cylindrical bulges on the second lower heat storage die part.

The further technical scheme of the invention is as follows: the auxiliary heat storage block is axially provided with a through hole, and the thermocouple is inserted into the center of the bottom surface of the turbine disc through the lower containing shell, the first lower heat storage die part, the second lower heat storage die part and the through hole in the auxiliary heat storage block to measure the temperature in real time.

The further technical scheme of the invention is as follows: a regulation and control method of a turbine disk gradient temperature field regulation and control device is characterized by comprising the following steps:

the method comprises the following steps: adding different numbers of heat storage blocks at the cavity of the heat storage die, establishing a tool geometric model by adopting drawing software, carrying out numerical simulation on the gradient heat treatment process of the turbine disc by utilizing finite element simulation software, and predicting the change trend of the temperature field distribution on the turbine disc along with time under different tool structures and furnace temperatures;

step two: establishing a grain size model during heat treatment of the target material, and predicting the change trend of grain size distribution on the turbine disk along with time under different temperature fields by using finite element simulation software in combination with the prediction result of the temperature field on the turbine disk in the step one;

step three: according to the results of the first step and the second step, establishing a relation database of a tool structure, the temperature in the furnace, the turbine disc gradient temperature field and the tissue field;

step four: and (4) selecting a proper tool structure and the temperature in the furnace from the database established in the third step to perform a gradient heat treatment test according to the target grain size distribution of the turbine disk, so as to realize the active control of the gradient temperature field and the grain size distribution of the turbine disk.

Effects of the invention

The invention has the technical effects that: because the cavity is designed in the central part of the heat storage mould, auxiliary heat storage blocks with different sizes and numbers can be freely added, the adjustment of the heat storage capacity of the heat storage mould is realized, if the auxiliary heat storage blocks are increased, the heat transferred from the edge of the turbine disc is absorbed more by the heat storage blocks in the central part, and a foundation is laid for the free adjustment of the temperature gradient, which is an advantage that the gradient heat treatment device designed in the U.S. patent application No. US 6660110B1 does not have. Meanwhile, by combining finite element numerical simulation, the prediction of the gradient temperature field and the grain size distribution on the turbine disc can be realized, and an effective solution is provided for the accurate regulation and control of the temperature gradient under the target grain size distribution of the turbine disc by establishing a relation database of the shape and the size of the tool, the temperature in the furnace and the gradient temperature field of the turbine disc.

Drawings

FIG. 1 is a schematic diagram of a gradient heat treatment device for preparing a dual-performance superalloy disk according to the invention

FIG. 2 is a schematic view of an adjustable superalloy turbine disk gradient heat treatment apparatus according to the present invention

FIG. 3 is a schematic view of the upper shell

FIG. 4 is a schematic view of an upper thermal storage mold

FIG. 5 is a schematic view of a lower thermal storage mold part one

FIG. 6 is a schematic view of the lower thermal storage mold part two

FIG. 7 is a schematic view of a lower shell

FIG. 8 is a schematic view of an auxiliary heat storage block

FIG. 9 is a schematic view of a base

FIG. 10 is a photograph of an assembled turbine disk and gradient heat treatment tool

FIG. 11 is a geometric model of turbine disk gradient heat treatment tooling with different auxiliary heat storage blocks added

FIG. 12 shows the gradient temperature field distribution of a turbine disk heat-treated for 4h with different auxiliary heat storage blocks

FIG. 13 is a schematic representation of grain size distribution of a turbine disk heat treated for 4 hours with the addition of different auxiliary heat storage blocks, as indicated by the reference numerals: 1-upper shell; 2, mounting a heat storage mold; 3, heat insulation cotton; 4-hexagon bolt; 5-auxiliary heat storage block; 6-turbine disk; 7-a first lower regenerative mold part; 8-a second lower thermal storage mold part; 9-lower container shell; 10-a base.

Detailed Description

Referring to fig. 2-13, the present invention will be further described with reference to specific embodiments. The following examples are intended to illustrate the invention only and are not intended to limit the scope of the invention.

The invention solves the problem of insufficient free regulation and control of the temperature gradient of the turbine disc and adopts the technical scheme that: the method combines the structure, the size design and the finite element numerical simulation calculation of the heat storage block, establishes a database of the gradient temperature field of the turbine disk changing along with the design of the tool, researches and develops a steady temperature gradient regulation and control method based on the distribution relation of the shape and the size of the tool, the temperature in a furnace and the temperature field of the turbine disk, and is characterized by comprising the following steps of:

(1) designing a gradient heat treatment device capable of freely adding different auxiliary heat storage blocks, and referring to the attached figures 2-9. The adjustable gradient heat treatment device comprises an upper containing shell 1, an upper heat storage mold 2 with a cavity, heat insulation cotton 3, a hexagon bolt 4, a first lower heat storage mold part 7, a second lower heat storage mold part 8 with a cavity, a lower containing shell 9 and a base 10. The upper containment shell 1 has two lug-shaped projections (length 60mm, width 60mm, height 15mm) parallel to the ground for quick disassembly after completion of the heat treatment (see figure 3). Hold shell 1 internal diameter 232mm on, external diameter 252mm has four diameters and is 30mm, the degree of depth is that the blind hole of 5mm cooperatees with the arch in last heat accumulation mould 2, its center department has the through-hole that the diameter is 13.2mm, it has four diameters and is 30mm to go up heat accumulation mould 2, highly be 25 mm's cylindric arch, center department has M12's screw hole (see figure 4), go up heat accumulation mould 2 and hold on and be connected through hex bolts 4 between the shell 1, guarantee 20 mm's interval between the two for fill thermal-insulated cotton 3. The lower thermal storage mold is divided into two parts, wherein the first lower thermal storage mold part 7 is provided with an annular groove having an inner diameter of 105mm and a width of 5mm (see fig. 5), and the second lower thermal storage mold part 8 is provided with an annular projection having an inner diameter of 105mm and a width of 5mm, which is fitted into the annular groove of the first lower thermal storage mold part 7. The second lower thermal storage mold member 8 has four cylindrical protrusions (see fig. 6) with a diameter of 30mm and a height of 25mm, and the lower containment shell 9 has four circular depressions (see fig. 7) with a diameter of 30mm and a depth of 5mm, which are fitted with the cylindrical protrusions of the second lower thermal storage mold member 8 so as to have a space of 20mm therebetween, for filling the thermal insulation wool 3. The upper thermal storage mold 1 and the second lower thermal storage mold member 8 have therein a cylindrical cavity having a diameter of 80mm for placing the auxiliary thermal storage block 5 (see fig. 2 and 8). Through holes having a diameter of 10mm are formed in the auxiliary heat accumulation block 5, the first and second lower heat

accumulation mold parts

7 and 8, and the lower containment shell 9, for inserting thermocouples. The bottom of the lower container shell 9 is provided with four cylindrical bulges with the diameter of 30mm and the height of 20mm, and four pits with the diameter of 30mm and the depth of 10mm (see attached figure 9) are matched with the cylindrical bulges on the lower container shell 9 on the base 10, so that the gravity center of the whole gradient heat treatment tool is reduced, and the stability is enhanced. A picture of the turbine disc assembled with the gradient heat treatment tool is shown in fig. 10.

(2) The heat storage capacity of the heat storage mold is adjusted by adding different numbers of auxiliary heat storage blocks at the cavity, so that the temperature of the central area of the disc is changed, and the temperature gradient on the turbine disc is effectively adjusted. A turbine disc gradient heat treatment tool geometric model is established by adopting AUTO CAD drawing software, referring to an attached drawing 11, and a finite element numerical simulation technology is combined, so that the trend of the temperature field and the grain size distribution on a turbine disc changing along with time is predicted, the influence rule of different auxiliary heat storage blocks on the temperature gradient is obtained through research, a tool shape and size-furnace temperature-turbine disc gradient temperature field relation database is established, and a turbine disc gradient temperature field regulation and control method is developed on the basis.

Taking a GH4586 alloy turbine disk gradient heat treatment process as a specific implementation object, firstly, designing a gradient heat treatment device capable of freely adding different auxiliary heat storage blocks, referring to fig. 2, wherein materials of an upper containing shell 1, an upper heat storage mold 2, a first lower heat storage mold part 7, a second lower heat storage mold part 8, a lower containing shell 9, a base 10 and an auxiliary heat storage block 5 in the GH4586 alloy turbine disk gradient heat treatment device are GH4202 alloy, and a thermocouple is R-type platinum-rhodium 13-platinum thermocouple. In the gradient heat treatment process, an upper containing shell 1, an upper heat storage die 2, an auxiliary heat storage block 5 and heat insulation cotton 3 are combined and connected through a hexagon bolt 4, a first lower heat storage die part, a second lower heat storage die part 8, the auxiliary heat storage block 5, a lower containing shell 9, the heat insulation cotton 3 and a base 10 are combined, a turbine disc 6 and the gradient heat treatment tool are combined and placed in a common heat treatment furnace for gradient heat treatment test, a thermocouple is inserted into the center of the bottom surface of the turbine disc through holes in the lower containing shell 9, the first lower heat storage die part 7, the second lower heat storage die part 8 and the auxiliary heat storage block 5, and the temperature is measured in real time.

Adopting AUTOCAD drawing software to establish a geometric model of a GH4586 alloy turbine disk gradient heat treatment tool, referring to the attached drawing 11, and carrying out numerical simulation on the GH4586 alloy turbine disk gradient heat treatment process by using finite element simulation software ABAQUS, wherein the method mainly comprises the following steps:

(1) establishing an axisymmetric geometric model in a PART module;

(2) the material of a turbine disc arranged in the PROPERTY module is GH4586 alloy, the material of a heat storage block and a shell is GH4202 alloy, and the material of a heat insulation layer is heat insulation cotton;

(3) assembling all parts in an ASSEMBLE module according to tool design;

(4) in the STEP module, selecting the solving type as heat transfer, and setting the automatic adjusting range of the incremental STEP;

(5) setting related physical performance parameters such as master-slave property of contact surfaces among all components, interface heat transfer coefficient of the contact surfaces, material emissivity coefficient (0.75 of metal material; 0.5 of heat insulation cotton) and the like in an INTERACTION module;

(6) setting the initial temperature of the tool in the Load module to be 20 ℃, and setting the ambient temperature to be T_DMHT＝1120℃；

(7) Meshing the individual components in the MESH module, the MESH type being selected as DCAX4 (four node axisymmetric heat transfer unit);

(8) and performing Data check on the model in the JOB module, and submitting the model Inp file and the USDFLD subprogram together for calculation through an ABAQUS/COMMON window after the model is confirmed to be correct.

Different auxiliary heat storage blocks are added in the cavity, and the distribution trend of the temperature field and the grain size on the turbine disc is predicted by combining a finite element numerical simulation technology, referring to fig. 12 and 13, the influence rule of the different auxiliary heat storage blocks on the temperature gradient and the grain size distribution when the heat treatment time is 4h is obtained through research, as can be seen from fig. 12 and 13, the more the auxiliary heat storage blocks are, the larger the temperature gradient on the GH4586 alloy turbine disc is, the larger the grain size grade difference is, and on the basis, the GH4586 alloy turbine disc gradient temperature field accurate regulation and control method can be developed according to the target grain size distribution by establishing a tool shape, size, furnace temperature and turbine disc gradient temperature field relation database.

Claims

1. A turbine disc gradient temperature field regulating device comprises an upper containing shell (1), a lower containing shell (9), a base (10) and heat insulation cotton (3), wherein a turbine disc to be treated is positioned between the upper containing shell (1) and the lower containing shell (9) and is coaxially arranged; the base (10) is connected with the lower containing shell (9); the heat-storage type solar heat-storage device is characterized by further comprising an upper heat-storage mould (2), a first lower heat-storage mould part (7), a second lower heat-storage mould part (8) and an auxiliary heat-storage block (5); the upper heat storage mold (2) is positioned in the upper containing shell (1), and heat insulation cotton (3) is filled between the upper heat storage mold and the upper containing shell; the first lower heat storage mould component (7) and the second lower heat storage mould component (8) are positioned in the lower shell (9), heat insulation cotton (3) is filled between the first lower heat storage mould component (7) and the lower shell (9) and between the second lower heat storage mould component (8) and the lower shell (9); one end of the second lower heat storage mould part (8) is connected with the lower containing shell (9), and the other end is connected with the first lower heat storage mould part (7); the upper containing shell (1), the lower containing shell (9), the upper heat storage mold (2) of the base (10), the first lower heat storage mold component (7) and the second lower heat storage mold component (8) are coaxially arranged; a plurality of auxiliary heat storage blocks are arranged in the heat storage die part, and the turbine disc gradient temperature field can be freely regulated and controlled by arranging different numbers to form different shapes.

2. The turbine disk gradient temperature field regulation and control device as claimed in claim 1, characterized in that the upper containing shell (1) is a cylindrical body as a whole, the interior of the upper containing shell is a cavity, one end of the upper containing shell is open, the other end of the upper containing shell is closed, and the open end of the upper containing shell is in contact with the turbine disk to be treated; ear-shaped bulges parallel to the ground are arranged on two sides of the closed end and used for quick disassembly; the end face of the closed end is provided with a blind hole, and the center of the blind hole is provided with a through hole.

3. The turbine disk gradient temperature field regulation and control device of claim 1, characterized in that the upper heat accumulation mold (2) is in a convex shape as a whole, one end of the upper heat accumulation mold is open and the other end is closed, the open end is fixedly connected with the closed end of the upper containing shell (1), and the convex end is contacted with the center of the turbine disk to be processed.

4. A turbine disc gradient temperature field regulation device according to claim 2 or 3, characterized in that a plurality of auxiliary heat storage blocks (5) and heat insulation cotton (3) are placed in the cavity between the upper containment shell (1) and the upper heat storage mold (2).

5. A turbine disk gradient temperature field regulating device according to claim 1, wherein said first lower heat accumulating mold member (7) is centrally provided with a through hole, and is provided with an annular groove at one end and blind holes symmetrically provided along the central axis at the other end.

6. A turbine disk gradient temperature field regulating device according to claim 1, wherein the second lower heat accumulating mold member (8) is provided with a through hole along the axis and an annular protrusion at one end thereof to be fitted into an annular groove of the first lower heat accumulating mold member (7); the other end is provided with a plurality of cylindrical bulges along the circumferential direction of the axis.

7. A turbine disc gradient temperature field regulating device according to claim 5 or 6, characterized in that one end of the first lower heat accumulating mould part (7) is in contact with the turbine disc to be treated, and the other end is connected with the second lower heat accumulating mould part (8) to form a cavity, and a plurality of auxiliary heat accumulating blocks (5) and heat insulating cotton (3) are placed in the cavity.

8. A turbine disc gradient temperature field regulating device according to claim 1, characterized in that one end of the lower housing shell (9) is open and closed, the closed end is axially provided with a through hole, and a plurality of circular pits are uniformly distributed on the end surface of the closed end along the axial direction and are matched with a plurality of cylindrical bulges on the second lower heat accumulation mould part (8).

9. The turbine disk gradient temperature field regulation and control device of claim 1, characterized in that the auxiliary heat storage block (5) is axially provided with a through hole, and a thermocouple is inserted into the center of the bottom surface of the turbine disk through the through holes on the lower container shell (9), the first lower heat storage mold part (7), the second lower heat storage mold part (8) and the auxiliary heat storage block (5) to measure the temperature in real time.

10. The method for regulating and controlling the turbine disk gradient temperature field regulation and control device based on claim 1 is characterized by comprising the following steps of:

step three: establishing a relation database of a tool structure, the temperature in the furnace, the turbine disc gradient temperature field and the tissue field according to the results of the first step and the second step;