A process for forming 321 solution-treated stainless steel abrasion-resistant plates for aircraft.

Abstract

This invention discloses a process forming method for 321 solution-treated stainless steel wear-resistant plates used in aircraft, comprising the following steps: S1, blanking; S2, processing the deep-drawing protrusion using a hot drawing die to obtain a primary processed part; S3, cutting the inner ring allowance of the waist-shaped hole; S4, processing the flanging using a hot flanging die to obtain a secondary processed part; S5, dividing the secondary processed part into four part blanks, and cutting lugs with process positioning holes on the part blanks to obtain a tertiary processed part; S6, processing the bending angle of each side using a bending die to obtain a quaternary processed part; S7, correcting by hand molding to obtain the final part. This invention, by analyzing the shape and structural characteristics of the part, and the special structure of the 321 solution-treated stainless steel wear-resistant plate, allows four wear-resistant plates to be assembled into one piece for processing, or to be assembled into one piece with parts of similar shape characteristics for processing. By fully considering the characteristics of the mold, a reasonable process forming method is formulated, solving practical production problems.

Description

Technical Field

[0001] This invention belongs to the field of aerospace parts processing, specifically relating to a process forming method for 321 solution-treated stainless steel wear-resistant plates used in aircraft. Background Technology

[0002] 321 solution-treated stainless steel is a titanium-stabilized chromium-nickel austenitic stainless steel. It is difficult to form at room temperature and requires heating to a certain temperature to improve the plasticity of the parts before it can be formed effectively. Hot forming introduces some uncontrollable factors due to the added temperature element. The abrasion protection plate material used in a certain aircraft uses 321 solution-treated stainless steel, and its structure differs from that of ordinary abrasion protection plates. The shape of the 321 solution-treated stainless steel abrasion protection plate 100 is as follows... Figure 1 As shown, the cross-sectional shape is as follows Figure 2 As shown, this part presents the following challenges compared to conventional parts: it has three bends, each on only one side, with relatively high bend heights. The uppermost bend has a 64° closed angle. In conventional part forming, forming a single-sided bend easily generates lateral forces and can negatively impact product quality. However, this part has three bends, with the uppermost bend having a negative angle of 64°. Existing processing methods involve: blanking → cutting (cutting out the unfolded shape) → stamping (stamping each bend in stages) → stamping the curved surface → shaping. However, stamping the bends and stamping the negative angles is difficult, easily leading to deformation and wrinkles, and even scrapping the part. Furthermore, existing processing methods can only process one product at a time, resulting in a large amount of shaping work. Therefore, it is necessary to design a reasonable process forming method to produce qualified parts. Summary of the Invention

[0003] The purpose of this invention is to design a reasonable process forming method for 321 solution-treated stainless steel wear-resistant plates with special structures, so as to guide production.

[0004] Technical solution of the present invention:

[0005] A forming method for 321 solution-treated stainless steel abrasion-resistant plates used in aircraft, the method employing a four-die forming process: hot drawing die → hot flanging die → bending die → hand-forming straightening die. The forming method includes the following steps:

[0006] The forming process includes the following steps:

[0007] S1. Material cutting: Select a stainless steel plate that meets the requirements in terms of material, wall thickness, and size. Make a waist-shaped hole in the middle of the stainless steel plate, and use a file to trim the rough edges and level it.

[0008] S2. Use a hot drawing die to process the deep drawing protrusion to obtain a primary processed part;

[0009] S3, Cut the inner ring allowance of the waist-shaped hole;

[0010] S4. Use a hot flanging die to process the flanging to obtain a secondary processed part;

[0011] S5. Divide the secondary processed part into four part blanks, and cut out ear pieces with process positioning holes on the part blanks to obtain the tertiary processed part.

[0012] S6. Position the three-processed part on the lower die of the bending die through the process positioning hole, and use the bending die to process the bending angle of each side to obtain the four-processed part.

[0013] S7. Correct the shape by hand to obtain the final part.

[0014] Furthermore, before the hot drawing die processing in step S2 and the hot flanging die processing in step S4, the workpiece and the hot drawing die are cleaned with acetone, and boron nitride high-temperature protective agent is sprayed onto the workpiece and the die surface.

[0015] Furthermore, in step S2, the hot drawing die forming parameters are as follows: maximum forming temperature is 260℃, preheating time is 10 minutes, upper die forming pressure is 230T, lower die top cylinder pressure is 15T, and heat and pressure holding time is 10 minutes.

[0016] Furthermore, in step S4, the hot flanging die forming parameters are as follows: maximum forming temperature is 260℃, preheating time is 10 minutes, upper die forming pressure is 230T, lower die top cylinder pressure is 15T, and heat preservation and pressure holding time is 10 minutes.

[0017] This invention analyzes the shape and structural features of parts and the special structure of 321 solution-treated stainless steel wear-resistant plates. It allows four wear-resistant plates to be assembled into one piece for processing, or to be assembled into one piece with parts of similar shape features for processing. By fully considering the characteristics of the mold, a reasonable process forming method is formulated, thus solving practical production problems. Attached Figure Description

[0018] Figure 1 This is a structural schematic diagram of a 321 solution-treated stainless steel wear-resistant plate in the prior art.

[0019] Figure 2 This is a cross-sectional view of a 321 solution-treated stainless steel wear-resistant plate in the prior art;

[0020] Figure 3 This is a blanking diagram of an embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of the structure of the hot drawing die in an embodiment of the present invention;

[0022] Figure 5 This is a diagram showing the forming arrangement of the stainless steel sheet in the hot drawing die in an embodiment of the present invention;

[0023] Figure 6This is a schematic diagram of the material cutting after hot drawing and deep die forming according to an embodiment of the present invention;

[0024] Figure 7 for Figure 6 Sectional view along AA;

[0025] Figure 8 This is a schematic diagram of the structure of the hot flanging die in an embodiment of the present invention;

[0026] Figure 9 This is a schematic diagram of the structure of the part that has undergone three processing steps in an embodiment of the present invention;

[0027] Figure 10 This is a schematic diagram of the bending die structure in an embodiment of the present invention;

[0028] Figure 11 This is a cross-sectional view of the bending die in an embodiment of the present invention. Detailed Implementation

[0029] The present invention can be further described through the following embodiments; however, the scope of the present invention is not limited to the following embodiments.

[0030] Example: Based on the characteristics of the 321 solution-treated stainless steel wear-resistant plate 100, four sets of molds are used for forming: hot drawing die → hot flanging die → bending die → hand-forming straightening die. The forming method includes the following steps:

[0031] The forming process includes the following steps:

[0032] S1. Material cutting: Based on the shape characteristics of the 321 solution-treated stainless steel wear-resistant plate 100, it was found that the wear-resistant plate is relatively flat except for the bent parts. Through analysis and comparison, it was found that the unfolded shape of the four wear-resistant plates 100 is approximately a rectangle. Therefore, the four wear-resistant plates 100 can be assembled into one piece for processing. In addition, there are other parts on the aircraft with similar shape characteristics to the wear-resistant plate, which can also be assembled into one piece with the wear-resistant plate.

[0033] Specifically, such as Figure 3 As shown, when cutting the material, select a stainless steel plate 1 that meets the requirements in terms of material, wall thickness and size. Make a waist-shaped hole 11 in the middle of the stainless steel plate 1 to facilitate the material flow in the mold without being pulled. Use a file to trim the burrs and level the parts. Note: The surface is not allowed to have defects such as hammer marks, scratches, pits and so on. Sandpaper can be used to remove hammer marks, surface scratches and pits and so on.

[0034] S2, such as Figure 4 and Figure 5 As shown, a deep-drawing protrusion is machined using a hot-drawing die to obtain a primary machined part;

[0035] Specifically, before processing, the workpiece and hot drawing die are cleaned with acetone, and boron nitride high-temperature protective agent is sprayed on the workpiece and die surface. After the hot drawing die is installed, it is installed on the press. The ejector pin in the middle of the lower platform of the press is placed into the ejector pin hole of the hot drawing die. The upper die of the hot drawing die is pressed tightly with a pressure plate, and the lower die is pressed down slightly with a pressure plate. The mold closing gap between the upper and lower dies is adjusted, the upper die is lowered, and then the lower die is pressed tightly with a pressure plate. The upper platform of the press is raised, and the ejector pin is checked to see if it is installed in place and if it can work normally. Forming parameters: Forming temperature: maximum 260℃, preheating time 10 minutes, forming pressure: upper die 230T, lower die ejector cylinder pressure 15T, heat and pressure holding time: 10 minutes.

[0036] S3, Cut the inner ring allowance of the waist-shaped hole; after hot drawing die forming, specifically, see... Figure 6 and Figure 7 As shown, draw a 45mm cutting line along the curved edge, cut off the inner circle excess along the 45mm line, and remove burrs.

[0037] S4. Use a hot flanging die to process the flanging to obtain a secondary processed part;

[0038] Specifically, after cutting off the excess material inside the ring, clean the flanging die with acetone, and spray boron nitride high-temperature protective agent onto the secondary processed parts and die surface, according to... Figure 8 As shown, install the hot flanging die and mount it on the press. Forming parameters: Forming temperature: maximum 260℃, preheating time: 10 minutes, forming pressure: upper die 230T, lower die top cylinder pressure 15T, heat preservation and pressure holding time: 10 minutes.

[0039] S5. Divide the secondary processed part into four part blanks, and cut out the ear piece 2 with process positioning hole 21 on the part blanks to obtain the tertiary processed part.

[0040] Specifically, after forming in the hot flanging die, a cutting allowance line is drawn on the secondary processed part using a scribing template (with an allowance of more than 3mm around the edges). Four tertiary processed parts with ear pieces 2 are cut out. A Φ5 process positioning hole 21 is drilled on each ear piece 2, and the ear piece allowance is retained (see...). Figure 9 Mark the cut-out parts blanks to prevent parts from being mixed up.

[0041] S6. Position the three-processed part on the lower die of the bending die through the process positioning hole 21, and use the bending die to process the bending angle of each side to obtain the four-processed part.

[0042] The cut parts with process lugs are formed on the lower die of the bending die.

[0043] Specifically, such as Figure 10 and Figure 11As shown, the bending die is installed on the press. Two holes matching the process positioning holes 21 are drilled on the lower die of the bending die and positioned with pins. After the part is positioned on the lower die of the bending die, the press drives the upper die of the bending die to move downward and press out the bending angle of each bending edge.

[0044] S7. Correct the shape by hand to obtain the final part.

[0045] Specifically, after forming on the lower die of the bending die, the part is manually corrected, and the theoretical outline of the part is drawn using a scribing template. Note: Use pins to fix the four-times-processed part and the scribing template on the hand-made die for scribing. After scribing, leave a 3mm allowance around the edges as the cutting line. Cut the part's outline, leaving a 0.8mm filing allowance around the edges to retain the cutting line drawn by the fitter. After cutting, deburr, correct the part, remove the lugs, and file the part's outline to meet the requirements.

[0046] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects. The scope of the invention is defined by the appended claims rather than the foregoing description, and all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0047] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A process forming method for 321 solid solution stainless steel wear plate for aircraft, characterized by: This method uses four sets of molds for forming: hot drawing mold → hot flanging mold → bending mold → hand-forming straightening mold. The forming process includes the following steps: S1. Material preparation: Based on the shape characteristics of the 321 solution-treated stainless steel wear-resistant plate, it was found that the wear-resistant plate is relatively flat except for the bent parts. Through analysis and comparison, it was found that the unfolded shape of the four wear-resistant plates is approximately a rectangle, which means that the four wear-resistant plates can be assembled into one piece for processing. When preparing the material, select a stainless steel plate that meets the requirements in terms of material, wall thickness, and size. Make a waist-shaped hole in the middle of the stainless steel plate to facilitate the material flow in the mold without being pulled. Use a file to trim the rough edges and level the surface. S2. Use a hot drawing die to process the drawing protrusion to obtain a primary part; before processing, clean the part and the hot drawing die with acetone, and spray boron nitride high-temperature protective agent on the part and die surface. After installing the hot drawing die, install the hot drawing die on the press. Insert the ejector rod in the middle of the lower platform of the press into the ejector rod hole of the hot drawing die. Press the upper die of the hot drawing die with a pressure plate, and press the lower die slightly with a pressure plate. Adjust the mold closing gap between the upper and lower dies, lower the upper die, and then press the lower die with a pressure plate. Raise the upper platform of the press and check whether the ejector rod is installed in place and whether the ejector rod can work normally. Forming parameters: Forming temperature: maximum 260℃, preheating time 10 minutes, forming pressure: upper die 230T, lower die ejector cylinder pressure 15T, heat preservation and pressure holding time: 10 minutes; S3, Cut the inner ring allowance of the waist-shaped hole; S4. Use a hot flanging die to process the flanging, and obtain the secondary processed part; after cutting off the inner ring excess, clean the flanging die with acetone, spray boron nitride high-temperature protective agent on the secondary processed part and the die surface, install the hot flanging die, and install it on the press. Forming parameters: forming temperature: maximum 260℃, preheating time: 10 minutes, forming pressure: upper die 230T, lower die top cylinder pressure 15T, heat preservation and pressure holding time: 10 minutes; S5. Divide the secondary processed part into four part blanks, and cut out ear pieces with process positioning holes on the part blanks to obtain the tertiary processed part. S6. Position the three-stage processed part on the lower die of the bending die through the process positioning hole. Use the bending die to process the bending angle of each side to obtain the four-stage processed part. Install the bending die on the press. Drill two holes on the lower die of the bending die that match the process positioning hole and position them with pins. After the part is positioned on the lower die of the bending die, the press drives the upper die of the bending die to move down and press out the bending angle of each bending edge. S7. Correct the shape by hand to obtain the final part.

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