Solution aging temperature prediction model suitable for TC17beta forged disc and forged piece and modeling method thereof

Abstract

The invention discloses a solid solution aging temperature prediction model suitable for TC17beta forged disc forgings and a modeling method thereof, the prediction model is # imgabs0 #, Fe is the predicted solid solution temperature, Fs is the predicted aging temperature, and x is the section thickness of the disc forgings; a is a correction parameter, and when the cross section of the disc forge piece is in a cake shape, a is equal to 0; and when the cross section of the disc forging is cross-shaped, a is equal to 4. The forge piece development efficiency is improved, the development cost is reduced, and the forge piece strength and plasticity reach qualified matching; the method is suitable for large blisk forgings.

Description

Technical Field

[0001] The present invention belongs to the technical field of aviation forging materials, and particularly relates to a solution aging temperature prediction model applicable to TC17β forging disks and a modeling method thereof. Background Art

[0002] TC17 titanium alloy is an advanced aviation material, and its application in modern aero-engines is becoming more and more extensive. By changing the microstructure and its grain orientation of TC17 titanium alloy through hot deformation and heat treatment, the uniformity and properties of the material can be improved; especially the reasonable matching of strength and plasticity makes the overall strength and plasticity of TC17 forgings excellent.

[0003] With the requirements of lightweight and high thrust for aero-engines, forgings are developing towards large integral blisks, resulting in an increasingly thick and large cross-sectional size of the forgings. It is becoming more and more difficult to determine reasonable solution and aging temperatures through traditional methods. The traditional method is mainly the trial-and-error method. The so-called trial-and-error method is to first estimate and select a set of solution temperatures and aging temperatures for the forgings according to the effective cross-sectional size of the forgings, conduct forging trials, evaluate whether the matching of strength and plasticity is reasonable based on the tensile strength and plasticity data obtained from the dissection of the trial forgings. If the matching is unreasonable, the solution temperature or aging temperature is appropriately adjusted, and the forging is retried again. Then, based on the tensile results of the forging trial dissection test, evaluate whether the matching of strength and plasticity is reasonable and whether it is necessary to adjust the solution and aging temperatures for retrial. This process is repeated until the optimal solution temperature and aging temperature of the forging are found; it is inefficient and costly; and it is not applicable to large-sized forgings.

[0004] When heat-treating TC17 disk forgings at the same solution temperature and aging temperature, the larger the cross-section of the forging, the lower the strength and the higher the plasticity. On the contrary, the smaller the cross-section of the forging, the higher the strength and the lower the plasticity of the forging. In order to meet the requirements of room-temperature tensile properties, forgings with different cross-sectional scales cannot use the same solution temperature and aging temperature. Forgings with a larger cross-section need to increase the solution temperature and decrease the aging temperature to compensate for the strength loss caused by the thick and large cross-section of the forging to make its strength qualified. Forgings with a thinner and smaller cross-section usually need to appropriately decrease the solution temperature and increase the aging temperature to appropriately reduce the strength level of the forging and appropriately increase its plasticity to meet the index requirements.

[0005] A large number of studies have given the specific solution temperatures and aging temperatures of TC17 forgings with different shapes and sizes. However, there is a lack of accurate prediction of solution temperatures and aging temperatures, and even more lack of prediction of solution temperatures and aging temperatures for extremely thick and large-sized forgings. Based on this, the purpose of this application is how to determine reasonable solution temperatures and aging temperatures for TC17 forgings with different cross-sectional thicknesses at one time. Summary of the Invention

[0006] The purpose of the present invention is to provide a solution aging temperature prediction model and modeling method for TC17β forging disk forgings. The prediction model established by this method significantly improves the forging development efficiency, reduces the development cost, and achieves a qualified match between the strength and plasticity of the forgings; and is suitable for large integral disk forgings.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A solution aging temperature prediction model for TC17β forging disc forgings, the prediction model is Among them, F e is the predicted solution temperature, F s To predict the aging temperature, x is the cross-sectional thickness of the disc forging; a is the correction parameter. When the cross-sectional shape of the disc forging is a circular pancake, a=0; when the cross-sectional shape of the disc forging is a cross, a=4.

[0009] A method for constructing the above-mentioned solution aging temperature prediction model applicable to TC17β forging disc forgings comprises the following steps:

[0010] Step 1: Obtain the effective cross-sectional thickness of the known disc forging and the corresponding solution temperature and aging temperature;

[0011] Step 2: Fit the solid solution temperature-effective cross-sectional thickness relationship curve based on the solid solution temperature and effective cross-sectional thickness obtained in step 1, and derive the functional relationship between the solid solution temperature and effective cross-sectional thickness based on the curve. F e is the predicted solution temperature, x is the cross-sectional thickness of the disc forging;

[0012] Step 3: Fit the aging temperature-effective section thickness relationship curve based on the aging temperature and effective section thickness obtained in step 1, and derive the functional relationship between aging temperature and effective section thickness based on the curve. F s is the predicted solution temperature, x is the cross-sectional thickness of the disc forging;

[0013] Step 4: Obtain the effective section thickness of the disc forging, and calculate the solution temperature and aging temperature through the functional relationship between solution temperature and effective section thickness and the functional relationship between aging temperature and effective section thickness. Then, heat treat the prototype, measure the strength and plasticity of the prototype, and modify the functional relationship based on the measured strength and plasticity to obtain the final prediction model: Among them, F e is the predicted solution temperature, F s To predict the aging temperature, x is the cross-sectional thickness of the disc forging; a is the correction parameter. When the cross-sectional shape of the disc forging is a circular pancake, a=0; when the cross-sectional shape of the disc forging is a cross, a=4.

[0014] Further, the data of the effective cross-sectional thickness of the disk forging and the corresponding solution temperature and aging temperature are obtained from the accumulation of heat treatment of existing disk forgings, or obtained by continuously trial-producing and measuring the strength and plasticity of trial-produced parts through the trial-and-error method.

[0015] In the present invention, through experiments and statistics on the solution and aging temperatures of TC17 titanium alloy forging blanks with different effective cross-sectional thicknesses, calculation formulas for the solution temperature and aging temperature of forgings with different effective cross-sectional thicknesses are fitted. By combining with the typical shape of the forging and making corrections, scientific and reasonable calculation formulas for the solution and aging temperatures of the forging can be obtained. It completely eliminates the low efficiency and high cost of the traditional trial-production method, enables rapid and accurate calculation, achieves the best strength and plasticity matching of the forging, and realizes high efficiency and low cost in the development of forgings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic cross-sectional view of a disk forging in a circular cake shape.

[0017] Figure 2 [[ID=I3]]It is a schematic cross-sectional view of a disk forging in a cross shape.

[0018] Figure 3 It is a curve graph showing the relationship between solution temperature and cross-sectional thickness fitted in Embodiment 2 of the present invention.

[0019] Figure 4 It is a curve graph showing the relationship between aging temperature and cross-sectional thickness fitted in Embodiment 2 of the present invention. yDETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] Embodiment 1

[0021] This embodiment provides a solution and aging temperature prediction model applicable to TC17β forged disk forgings, and the prediction model is where F e is the predicted solution temperature, F s is the predicted aging temperature, x is the cross-sectional thickness of the disk forging; a is a correction parameter. When the cross-sectional shape of the disk forging is a circular cake shape, as shown in Figure 1 , a = 0; when the cross-sectional shape of the disk forging is a cross shape, as shown in Figure 2 , a = 4.

[0022] Through the prediction model provided in this embodiment, only the effective cross-sectional thickness and shape of the disk forging need to be obtained in advance to calculate the solution temperature and aging temperature, effectively improving the development efficiency of the forging and reducing the development cost.

[0023] Embodiment 2

[0024] This embodiment provides a method for establishing a solution aging temperature prediction model for the TC17β forging disk forgings described in Embodiment 1, including the following steps:

[0025] Step 1: Obtain the solution temperatures and aging temperatures of a large number of existing forgings with different effective cross-sectional thicknesses. The strength and plasticity of the forgings heat-treated under this combination of solution temperature and aging temperature are excellent.

[0026] As shown in Table 1, the solution temperatures and aging temperatures corresponding to forgings with different effective cross-sectional thicknesses. The strength and plasticity of the forgings after heat treatment at this solution temperature and aging temperature are excellent. This data is obtained from the long-term accumulation of heat treatment of a large number of forgings in our company, or can also be obtained through the trial-and-error method by continuously trial-producing and measuring their strength and plasticity.

[0027] Table 1 Solution temperatures and aging temperatures corresponding to forgings with different effective cross-sectional thicknesses

[0028] Effective cross-sectional thickness of forging (mm) Shape of disk forging Solution temperature (°C) Aging temperature (°C) 63.5 Cross-sectional shape is round cake 800 628 64 Cross-sectional shape is round cake 800 627 70 Cross-sectional shape is round cake 802 622 75 Cross-sectional shape is round cake 803 621 81 Cross-sectional shape is round cake 804 621 85.5 Cross-sectional shape is round cake 805 618 104.9 Cross-sectional shape is round cake 806 616 131 Cross-sectional shape is round cake 808 615 146 Cross-sectional shape is round cake 809 613 179 Cross-sectional shape is round cake 811 613 200 Cross-sectional shape is round cake 813 610

[0029] Step 2: Fit a solution temperature-cross-sectional thickness relationship curve according to the different effective cross-sectional thicknesses and solution temperatures in Table 1, as Figure 3 shown, and obtain the functional relationship between the solution temperature and the cross-sectional thickness from the fitted curve F e is the predicted solution temperature, and x is the cross-sectional thickness of the disk forging.

[0030] Step 3: Fit an aging temperature-cross-sectional thickness relationship curve according to the different effective cross-sectional thicknesses and aging temperatures in Table 1, as Figure 4 shown, and obtain the functional relationship between the aging temperature and the cross-sectional thickness of the fitted curve F s is the predicted aging temperature, and x is the cross-sectional thickness of the disk forging.

[0031] Step 4: Modify the functional relationship. By substituting the effective cross-sectional thickness of the disk forging in Table 1 into the functional relationship between the solution temperature and the cross-sectional thickness and the functional relationship between the aging temperature and the cross-sectional thickness, calculate the solution temperature and the aging temperature. The results are shown in Table 2. According to the trial-produced parts corresponding to the heat treatment in Table 2, and detect their strength and plasticity, as shown in Table 3. According to the test results, modify the aging temperature to obtain the final aging temperature, as shown in Table 4. According to Table 4, heat-treat the trial-produced parts again and measure their strength and plasticity. The results are shown in Table 5.

[0032] Table 2 Calculated solution temperatures and aging temperatures

[0033]

[0034] Table 3 Tensile test results after calculating the solution aging temperature

[0035]

[0036]

[0037] Table 4 Actual Final High Plasticity Matching Temperature

[0038]

[0039] Table 5 Tensile Test Results after Modifying Heat Treatment Solution Aging Temperature

[0040]

[0041] It can be seen from Table 2 to Table 5 that the reason for the difference in aging temperature is constituted by the difference in the cross-sectional shape of the disk forgings. Therefore, in this embodiment, a correction parameter a is set in the functional relationship between the aging temperature and the cross-sectional thickness, and the functional relationship between the aging temperature - cross-sectional thickness When the cross-sectional shape of the disk forging is round cake type, a = 0; when the cross-sectional shape of the disk forging is cross type, a = 4.

[0042] The finally constructed prediction model is where F e is the predicted solution temperature, F s is the predicted aging temperature, x is the cross-sectional thickness of the disk forging; a is the correction parameter. When the cross-sectional shape of the disk forging is round cake type, the round cake type disk forging is as Figure 1 shown, a = 1; when the cross-sectional shape of the disk forging is cross type, the cross type disk forging is as Figure 2 shown, a = 4.

[0043] The above are only the preferred embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any modification and replacement based on the technical solutions and inventive concepts provided by the present invention should be covered within the protection scope of the present invention.

Claims

1. A solution aging temperature prediction model applicable to TC17β disk forging forgings, characterized in that: The prediction model is where F e is the predicted solution temperature, F s is the predicted aging temperature, x is the cross-sectional thickness of the disk forging; a is a correction parameter, when the cross-sectional shape of the disk forging is round cake type, a = 0; when the cross-sectional shape of the disk forging is cross type, a = 4.

2. A method for constructing a solution aging temperature prediction model for the TC17β forging disk forging described in claim 1, characterized in that, It includes the following steps: Step 1: Obtain the effective cross-sectional thickness of the known disk forging and the corresponding solution temperature and aging temperature; Step 2: Fit the solution temperature-effective cross-section thickness relationship curve based on the solution temperature and effective cross-section thickness obtained in Step 1, and obtain the functional relationship between the solution temperature and effective cross-section thickness according to the curve F e is the predicted solution temperature, and x is the cross-section thickness of the disk forging; Step 3: Fit the aging temperature-effective cross-sectional thickness relationship curve based on the aging temperature and effective cross-sectional thickness obtained in Step 1, and obtain the functional relationship between the aging temperature and the effective cross-sectional thickness according to the curve. F s is the predicted solution temperature, and x is the cross-sectional thickness of the disk forging. Step 4: Obtain the effective cross-sectional thickness of the disk forging, calculate the solution temperature and aging temperature through the functional relationships between the solution temperature-effective cross-sectional thickness and the aging temperature-effective cross-sectional thickness, then heat-treat the trial parts, measure the strength and plasticity of the trial parts, correct the functional relationships based on the measured strength and plasticity, and obtain the final prediction model as where F e is the predicted solution temperature, F s is the predicted aging temperature, x is the cross-sectional thickness of the disk forging; a is a correction parameter, when the cross-sectional shape of the disk forging is a round cake type, a = 0; when the cross-sectional shape of the disk forging is a cross type, a = 4.

3. A method for constructing a solution aging temperature prediction model suitable for TC17β forging disks, according to claim 1, characterized in that, The data of the effective cross-sectional thickness of the disk forging and the corresponding solution temperature and aging temperature are obtained from the accumulation of heat treatment of existing disk forgings, or obtained by continuously trial-producing and measuring the strength and plasticity of trial-produced parts through the trial-and-error method.

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