Shot peening strengthening deformation restraining method for new-structure baffle based on FGH99 material

Abstract

The invention relates to an FGH99 material-based new structure baffle shot peening strengthening deformation suppression method, which comprises the following steps of: obtaining a stress deformation trend and an approximate range of a part after shot peening by adopting a subarea single-point shot peening mode, and accurately controlling the deformation of each area of the part by using a multi-step incremental process in shot peening processing on two sides of the part, so that the deformation of the part is inhibited. The deformation of the two sides of the part is repeatedly corrected, so that the stress deformation of the baffle made of the material after shot blasting is counteracted; according to the technical scheme, the extra machining time caused by size repairing and shot blasting repairing in the later period of the part is shortened, the part machining process is well controlled, and the percent of pass of products can be increased.

Description

Technical Field

[0001] The invention relates to the technical field of aeroengine powder alloy baffles, and in particular to a method for suppressing deformation of a baffle with a new structure based on FGH99 material through shot peening. Background Art

[0002] The manufacturing technology of aircraft engine blades is one of the most complex technologies in the turbine machinery manufacturing industry, and it is also a manufacturing technology that involves a wide range of professional fields in the machinery manufacturing industry. Therefore, the level of manufacturing technology of disc shaft parts as rotor parts reflects the level of engine manufacturing technology to a certain extent.

[0003] Shot peening is a method that can effectively improve the fatigue strength and stress corrosion cracking resistance of metals. Aircraft engine turbine baffle parts generally need to be shot peened. Conventional shot peening uses a method where the parts are placed horizontally and processed on two sides, that is, the parts are placed horizontally, and after shot peening one side, they are turned over and shot peened on the other side. Baffle parts are usually thin-walled structures with strict dimensional requirements. Under conventional shot peening methods, the parts are greatly deformed. It is usually necessary to reserve a margin before shot peening the parts and repair the matching dimensions after shot peening, and then locally re-shot peen the repaired parts to ensure the dimensional requirements of the parts after shot peening. The process is lengthy and the processing risk is relatively high. In the industry, in order to solve the problem of large deformation caused by shot peening, double-sided shot peening can also be used, but it often has high requirements on the functions of the shot peening equipment, such as dual-channel shot peening function, or one-to-two nozzles, etc. In addition, in order to achieve double spraying, it is also necessary to convert the clamping of parts from horizontal to vertical, which requires the design and manufacture of special customized fixtures. If some fixture designs use a clamping method, it will also affect the transformation of part stress. Therefore, this method also has many restrictions on the fixtures of parts. Although it has a certain inhibitory effect on deformation, its popularity is still insufficient. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a method for suppressing deformation by shot peening strengthening of a new structure baffle of FGH99 material; the specific technical scheme is as follows:

[0005] A method for suppressing deformation of a new structure baffle plate based on FGH99 material shot peening, comprising the following steps:

[0006] Step 1: Combine the material properties of the parts, analyze the structural characteristics of the parts, divide the parts into regions according to the structural characteristics of the parts, and divide the parts that are easily deformed during the shot peening process into multiple regions for separate treatment;

[0007] Step 2: Combined with the deformation of parts in the machining process before shot peening, the trend direction of parts deformation during shot peening is preliminarily determined and verified through actual processing;

[0008] Step 3: Determine the shot peening parameters according to the design requirements of shot peening intensity and coverage, taking compressed air pressure and shot flow rate as variables, and other parameters as quantitative given according to the actual process conditions of the parts;

[0009] Step 4: Shot peening is first performed on the surface of the part with the deformation trend upward. The first processing uses 0.7BAR-0.8BAR compressed air pressure to peen the surface of the part; the shot peening pressure parameter reaches 50% of the final design strength; note that if the coverage rate of the part surface is limited, the shot peening time should also be shortened accordingly;

[0010] Step 5: Shot peening is then performed on the reverse side of the part where the deformation trend is downward. When shot peening is performed on the reverse side of the part, the maximum air pressure and flow rate parameters that can be used are greater than the surface strength in the upward direction and do not exceed the maximum strength allowed by the design.

[0011] Step 6: According to the deformation of each area of ​​the part after two shot peening, turn the part back to the surface and perform a second shot peening using the parameters corresponding to the lower limit of the design strength, so that the surface strength and coverage meet the design requirements;

[0012] Step 7: If the above shot peening process still cannot effectively suppress deformation, steps 4 to 6 will be further refined.

[0013] The method for suppressing deformation by shot peening of a new structure baffle based on FGH99 material is preferably as follows: in step 4, the surface of the part is shot peened with compressed air at a pressure of 0.7BAR-0.8BAR for the first processing.

[0014] The method for suppressing deformation by shot peening of a new structure baffle based on FGH99 material is preferably as follows: in step five, attention should be paid to the shot peening sequence, first the small diameter and then the large diameter parts; when the deformation of the surface of the part is large after the first shot peening, the back of the part should be shot peened using the hitting intensity parameters allowed by the design drawing.

[0015] The method for suppressing deformation by shot peening of a new structure baffle based on FGH99 material is preferably as follows: in step five, the air pressure during shot peening of the back side of the part adopts an upper pressure limit of 1.8BAR, which is greater than the lower pressure parameter limit of 1.5BAR, and its strength cannot exceed the required range of the design, so as to resist the deformation superimposed when the surface of the part is subjected to secondary shot peening in the next step.

[0016] The method for suppressing deformation by shot peening of a new structure baffle based on FGH99 material is preferably as follows: in step six, the lower limit pressure parameter when the part surface is shot peened again is less than the pressure parameter on the back of the part, and the part surface is shot peened for the second time. Finally, the part surface shot peening reaches the strength required by the design, and the compressed air pressure for shot peening of the part surface is 1.5BAR.

[0017] The method for suppressing deformation by shot peening of a new structure baffle based on FGH99 material is preferably as follows: in step seven, the specific number of splits is more finely split according to the fineness of controlling the deformation of the parts, and the strength required by the design is gradually reached in multiple times, and the surface and back of the parts are cyclically shot peened to ensure that the deformation is balanced on both sides of the parts; the selection of specific parameters is fine-tuned in combination with the measurement results of the deformation of the parts, and the shot peening intensity must not exceed or be lower than the final design requirements. Fine-tuning can be performed in combination with the specific part structure to achieve better deformation control effects.

[0018] Beneficial Effects

[0019] Compared with the prior art, the present invention has the following beneficial technical effects:

[0020] The technology of the present invention mainly obtains the stress deformation trend and approximate range of parts after shot peening by adopting a partitioned single-point shot peening method, and uses a multi-step incremental process method in the shot peening process on both sides of the parts to accurately control the deformation of each area of ​​the parts, and repeatedly correct the deformation on both sides of the parts to offset the stress deformation of the baffle of this material after shot peening. The use of this process method can lower the threshold of equipment functions and special fixture design. Only using equipment with basic functions can effectively suppress the deformation of parts in the shot peening process, reduce the extra processing time caused by the later size repair and supplementary shot peening of parts, and the part processing process is better controlled, which is conducive to improving the product qualification rate. The above method can reduce the loss of scrap by hundreds of thousands of yuan each year. With the increase of the company's production capacity and the promotion and application of this technology, the economic benefits will be greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 In order to combine the material and structural characteristics of the parts, different regional schematic diagrams are divided according to their shot peening deformation conditions;

[0022] Figure 2 Schematic diagram of the trend direction of shot peening deformation of parts.

[0023] In the figure: 1-area a, 2-area b, 3-area c, 4-area d, 5-area e. DETAILED DESCRIPTION

[0024] The following is combined with Figure 1-2 The present invention is described in detail, but the protection scope of the present invention is not limited by the accompanying drawings.

[0025] A method for suppressing deformation of a new structure baffle plate based on FGH99 material shot peening, comprising the following steps:

[0026] Step 1: Confirm whether the material of the part is FGH99 or a material with equivalent characteristics, and divide the part into regions according to its structural characteristics, such as Figure 1 As shown, the thin and easily deformed parts of the parts are divided into five areas: area a1, area b2, area c3, area d4 and area e5;

[0027] Step 2: Combined with the deformation of the parts in the machining process before shot peening, determine the deformation trend of the parts in the shot peening process. Figure 2 As shown in the figure, its deformation trend is somewhat different from that of traditional parts shot peening. For example, the deformation trend of area a1 and area b2 in normal shot peening should be opposite to the impact direction of the projectile, while the deformation trend of this part is the same as the impact direction of the projectile, and the same situation also exists in other parts.

[0028] Step 3: When the part is impacted by the same intensity of projectiles on both sides, the deformation amount of the area a1 and area b2 side is larger toward the bottom, and the deformation amount of the area d4 and area e5 side toward the top is smaller, mainly because the area d4 contains a reinforcement structure. In view of this deformation trend, a multi-step incremental process method is used to perform shot peening strengthening;

[0029] Step 4: The shot peening design of the part surface area a1 and area b2 requires the compressed air pressure to be 1.5 BAR;

[0030] Use the shot peening pressure parameter that reaches 50% of the final design strength to perform shot peening on one side of area a1 and area b2. For the first processing, use 0.7BAR-0.8BAR of compressed air pressure to peen the surface of the part. Process area a1 first, then process area b2, and reach the shot peening pressure parameter of 50% of the final design strength. Note that if the coverage rate of the part surface is limited, the shot peening time should be shortened accordingly.

[0031] Step 5: Continue processing on the other side of the part, and perform shot peening on area c3, area d4, and area e5. During processing, the maximum intensity of the air pressure and flow parameters that are greater than the shot peening intensity of the upward surface should be used for shot peening;

[0032] Under the premise that other conditions remain unchanged, the air pressure is 1.8BAR, and the order of shot peening is from area c3 to area e5 and finally to area d4 to obtain the maximum deformation; the pressure is greater than the maximum 1.5BAR on the surface of the part, but cannot exceed the design requirements;

[0033] Step 6: Change the surface of the part, and continue to perform shot peening on area a1 and area b2. The shot peening time and shot peening intensity are both within the design tolerance range. Under the premise that other conditions remain unchanged, the air pressure adopts 1.2BAR pressure parameters; the pressure is less than 1.5BAR, but the intensity value cannot be lower than the design requirements; the processing order is to process area a1 first, and then area b2;

[0034] Step 7: The specific number of splits is based on the degree of detail of the part deformation control. The design strength is gradually reached in multiple times. The two sides are peened cyclically to ensure that the deformation is balanced on both sides of the part. The selection of specific parameters can be fine-tuned in combination with the measurement results of the part deformation. The peening intensity should not exceed or be less than the final design requirements. Fine-tuning combined with the specific part structure can achieve better deformation control effects.

Claims

1. A method for suppressing deformation by shot peening of a new structure baffle of FGH99 material, characterized in that: The steps include: Step 1: Combine the material properties of the parts, analyze the structural characteristics of the parts, divide the parts into regions according to the structural characteristics of the parts, and divide the parts that are easily deformed during the shot peening process into multiple regions for separate treatment; Step 2: Combined with the deformation of parts in the machining process before shot peening, the trend direction of parts deformation during shot peening is preliminarily determined and verified through actual processing; Step 3: Determine the shot peening parameters according to the design requirements of shot peening intensity and coverage, taking compressed air pressure and shot flow rate as variables, and other parameters as quantitative given according to the actual process conditions of the parts; Step 4: Shot peening is first performed on the surface of the part with the deformation trend upward. The compressed air pressure of 0.7BAR-0.8BAR is used for the first processing to peen the surface of the part; the shot peening pressure parameter reaches 50% of the final design strength; note that if the coverage rate of the part surface is limited, the shot peening time should also be shortened accordingly; Step 5: Shot peening is then performed on the reverse side of the part where the deformation trend is downward. When shot peening is performed on the reverse side of the part, the maximum air pressure and flow rate parameters that can be used are greater than the surface strength in the upward direction and do not exceed the maximum strength allowed by the design. Step 6: According to the deformation of each area of ​​the part after two shot peening, turn the part back to the first shot peening surface, and use the parameters corresponding to the lower limit of the design strength to perform a second shot peening, so that the surface strength and coverage meet the design requirements; Step 7: If the above shot peening process still cannot effectively suppress deformation, steps 4 to 6 will be further refined.

2. The method for suppressing deformation by shot peening of a new structure baffle of FGH99 material according to claim 1 is characterized in that: In step 4, the first processing uses 0.7BAR-0.8BAR compressed air pressure to shot peen the surface of the part.

3. The method for suppressing deformation by shot peening of a new structure baffle of FGH99 material according to claim 1 is characterized in that: In step five, attention should be paid to the shot peening sequence, first the small diameter and then the large diameter. When the deformation of the part surface is large after the first shot peening, the back of the part should be shot peened using the hitting intensity parameters allowed by the design drawing.

4. The method for suppressing deformation by shot peening of a new structure baffle of FGH99 material according to claim 1 is characterized in that: In step five, the air pressure during shot peening on the reverse side of the part adopts an upper pressure limit of 1.8 BAR, which is greater than the lower pressure limit of 1.5 BAR. Its strength cannot exceed the required range of the design and is used to resist the superimposed deformation during the secondary shot peening process on the part surface in the next step.

5. The method for suppressing deformation by shot peening of a new structure baffle of FGH99 material according to claim 1 is characterized in that: In step six, the lower limit pressure parameter of the part surface shot peening is less than the pressure parameter on the back of the part, and the part surface is shot peened for the second time. Finally, the part surface shot peening reaches the design strength, and the compressed air pressure of the part surface shot peening is 1.5BAR.

6. The method for suppressing deformation by shot peening of a new structure baffle of FGH99 material according to claim 1 is characterized in that: In step seven, the specific number of splits is based on the degree of detail of controlling the deformation of the parts, and the design strength is gradually reached in multiple times. The surface and back of the parts are shot peened cyclically to ensure that the deformation is balanced on both sides of the parts. The selection of specific parameters, combined with the measurement results of the deformation of the parts, can be fine-tuned to ensure that the shot peening intensity does not exceed or fall below the final design requirements. Fine-tuning can be performed in combination with the specific part structure to achieve better deformation control effects.

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