Ultrahigh-strength special-shaped barrel production process

Abstract

The invention relates to a production process of an ultrahigh-strength special-shaped barrel. The production process comprises the following steps: preparing a barrel blank according to the size; material distribution grooves are symmetrically formed in the positions, close to the two ends, of the outer side of the barrel, the sections of the material distribution grooves are triangular, the outer angle of the outer side edge of each triangle ranges from 94 degrees to 100 degrees, and the outer angle of the inner side edge of each triangle ranges from 140 degrees to 160 degrees; the local mandrel is drawn out, specifically, the heating number is 1-2, forging heating is conducted to 425-445 DEG C in each heating number, and only the part, located between the outer sides of the two material distribution grooves, of the barrel blank is drawn out; and local trestle reaming: 1-3 heating numbers, forging and heating each heating number to 425-445 DEG C, and only carrying out trestle reaming on the part of the barrel blank between the outer sides of the two material distribution grooves to drive the inner and outer diameters of flanges at the two ends of the barrel blank to grow together. According to the ultra-high-strength special-shaped barrel production process, materials are prevented from being accumulated at flanges at the two ends of a barrel body, meanwhile, the utilization rate of the materials is increased, the utilization rate of raw materials is increased to 38% from 28%, small-specification raw materials can be selected, and the forgeability, the formability and the structure are all allowed to be greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of forging, and in particular to a production process of an ultra-high strength special-shaped cylinder. Background Art

[0002] Aluminum alloy is one of the lightest structural metals and has great potential to improve energy efficiency in the aerospace, electronics, automotive and defense sectors due to its low density, high strength, easy recycling and outstanding corrosion resistance.

[0003] Aluminum alloy forgings are prone to coarse grain defects during forging production, which seriously affects their use in aerospace and other fields. Therefore, factors such as too small or too large deformation degree and deformation speed will affect the structure and performance of forgings.

[0004] When aluminum alloy is used to forge a special-shaped cylinder with flanges at both ends and an inner circle inside, the process route of forging-punching-expanding-mandrel drawing-horse frame expansion is usually used. When the product is produced by the traditional method, the design margin is large, and its material utilization rate is about 28%, which is low. Due to the large design margin, the feed weight is large, and a press of more than 10,000 tons must be used for forging. There are almost no domestic equipment that meets the production conditions, and the equipment cost is high. In addition, during the drawing and horse frame expansion, the material is easy to accumulate at the flanges at both ends of the cylinder, and the final forging is horn-shaped at both ends, with a low forming rate and poor uniformity of the structure after forming.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0006] In view of the shortcomings of the prior art, an embodiment of the present invention discloses a production process for an ultra-high strength special-shaped cylinder to solve the problems of high forging cost and low forming rate of the special-shaped cylinder.

[0007] The technical solution adopted by the present invention is as follows:

[0008] A production process for an ultra-high strength special-shaped cylinder comprises the following steps: preparing a cylinder blank according to the size; processing dividing grooves: symmetrically opening dividing grooves near the two ends of the outer side of the cylinder, the dividing grooves having a triangular cross-section, the outer angle of the outer side of the triangle being 94°-100°, and the outer angle of the inner side of the triangle being 140°-160°; local mandrel drawing: 1-2 times, forging and heating to 425-445°C in each time, only drawing the portion of the cylinder blank located between the outer sides of the two dividing grooves; local rack expansion: 1-3 times, forging and heating to 425-445°C in each time, only expanding the portion of the cylinder blank located between the outer sides of the two dividing grooves, so as to drive the inner and outer diameters of the flanges at both ends of the cylinder blank to grow together.

[0009] A further technical solution is that the outer angle of the outer side of the triangle of the material distribution trough is 97°, the outer angle of the inner side of the triangle is 150°, and the depth is 70-100 mm.

[0010] Its further technical solution is that in the local mandrel lengthening step, the hydraulic press pressing speed is 10-20mm / s, and the single hammer pressing amount is ≤25mm; in the local horse rack expanding step, the hydraulic press pressing speed is 10-20mm / s, and the single hammer pressing amount is ≤25mm.

[0011] Its further technical solution is that the steps of preparing the cylinder blank according to the size include: reforging and punching: 2 to 4 times, heating to 425 to 445°C during each forging, and cycling the process of chamfering, upsetting height, correcting bending, chamfering, upsetting width and correcting bending for several times until the blank reaches the set length, and then rounding, flattening the end face and punching; horse frame reaming: 1 to 2 times, heating to 425 to 445°C during each forging, and the pressing speed is 10 to 20 mm / s.

[0012] A further technical solution is that in the forging step, the pressing speed of the hydraulic press is 10 to 20 mm / s, and the inner circle of the barrel blank is machined after punching.

[0013] Its further technical solution is that after the step of local horse rack expansion, it also includes the following steps: machining: machining the forging to a set size; solid solution: heating to 464-484°C and keeping warm for 8 hours, water cooling, the water temperature is 35-45°C, and the water entry time interval is ≤15s.

[0014] Its further technical scheme is that after the solid solution step, it also includes the following steps: primary aging: heating to 105-115°C and keeping warm for 8 hours, and immediately heating up for secondary aging; secondary aging: heating to 160-170°C and keeping warm for 10 hours, and air cooling.

[0015] A further technical solution is that the weight percentage of each chemical element in the forging is:

[0016] Si: 0.06%; Fe: 0.11%; Cu: 1.68%; Mn: 0.02%; Mg: 2.8%; Cr: 0.2%; Zn: 5.8%; Ti: 0.04%; other elements: individual ≤ 0.05%, total ≤ 0.15%; the balance is Al.

[0017] The beneficial effects of the embodiments of the present invention are as follows:

[0018] (1) The present invention provides a production process for ultra-high strength special-shaped cylinders, by symmetrically opening dividing grooves near the two ends of the outer side of the cylinder, and adopting local mandrel stretching and local horse frame expansion for the portion of the cylinder blank located between the two outer sides of the dividing grooves, so that the middle part has a large deformation amount, and then drives the inner and outer diameters of the flanges at both ends of the cylinder blank to grow together, thereby avoiding the accumulation of materials at the flanges at both ends of the cylinder, and at the same time improving the utilization rate of materials, and increasing the utilization rate of raw materials from 28% to 38%, so that small-sized raw materials can be selected, and the forgeability, formability, and organization are allowed to be greatly improved.

[0019] (ii) Furthermore, the present invention performs heat treatment after machining to obtain a suitable shape, thereby avoiding the product being unable to be hardened due to excessive wall thickness, resulting in insufficient performance, and leaving sufficient margin to avoid deformation of the forging after heat treatment, resulting in a size that cannot meet the requirements of finished product processing. After heat treatment, a uniform structure and excellent tensile strength, yield strength and elongation are obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The present invention is a flow chart of a production process of an ultra-high strength special-shaped tube.

[0021] Figure 2 This is a cross-sectional view of the barrel blank after processing the dividing groove.

[0022] Figure 3 This is a cross-sectional view of the barrel blank after partial mandrel stretching and partial horse frame expansion.

[0023] Figure 4 This is a cross-sectional view of the barrel blank after machining.

[0024] Figure 5 This is a photo of a special-shaped barrel forging made using the prior art method.

[0025] Figure 6 The following is a photo of a special-shaped barrel forging produced by the method of the present invention (with people and logos coded).

[0026] Figure 7 This is the x200 metallographic result of the special-shaped cylinder forging made in Example 1 of the present invention.

[0027] Figure 8 This is a low-magnification microstructure photograph of the special-shaped cylinder forging prepared in Example 1 of the present invention.

[0028] In the figure:

[0029] 1. Cylinder body; 11. Flange; 12. Internal ribs; 2. Material distribution trough. DETAILED DESCRIPTION

[0030] The specific implementation of the present invention is described below in conjunction with the accompanying drawings.

[0031] In order to make the purpose, technical scheme and advantages of the present invention clearer, the device proposed by the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the accompanying drawings adopt a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, please refer to the accompanying drawings. It should be noted that the structure, proportion, size, etc. illustrated by the accompanying drawings of this specification are only used to match the content disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no technical substantive significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effect that the present invention can produce and the purpose that can be achieved, should still fall within the scope of the technical content disclosed by the present invention.

[0032] First embodiment:

[0033] A production process for an ultra-high strength special-shaped barrel comprises the following steps:

[0034] Step S1, forging and punching.

[0035] Specifically, the weight percentage of each chemical element in the forging is: Si: 0.06%; Fe: 0.11%; Cu: 1.68%; Mn: 0.02%; Mg: 2.8%; Cr: 0.2%; Zn: 5.8%; Ti: 0.04%; other elements: single ≤ 0.05%, total ≤ 0.15%; the balance is Al.

[0036] Perform 3 fire-forging, heat each fire forging to 435℃, and cycle several times according to the process of chamfering, upsetting height, correcting bending, chamfering, upsetting width and correcting bending until the blank reaches the set length, and then rounding, flat end surface and punching. In the forging step, the hydraulic press pressing speed is 15mm / s, and the inner circle of the barrel 1 blank is machined after punching.

[0037] Step S2, expanding the hole of the horse frame.

[0038] Specifically, one fire of horse rack expansion is carried out, each fire of forging is heated to 435°C, and the pressing speed is 15mm / s.

[0039] Step S3, processing the material distribution trough 2.

[0040] Specifically, the material distribution grooves 2 are symmetrically arranged near the two ends of the outer side of the cylinder 1. The cross section of the material distribution groove 2 is a triangle. The outer angle α of the outer side of the triangle is 97°, the outer angle β of the inner side of the triangle is 150°, and the depth is 85 mm.

[0041] Step S4, lengthening the local mandrel.

[0042] Specifically, one fire is performed for partial mandrel drawing, and each fire is heated to 435° C., and only the portion of the barrel 1 blank located between the outer sides of the two dividing grooves 2 is drawn. In the partial mandrel drawing step, the hydraulic press has a pressing speed of 15 mm / s, and the single hammer pressing amount is ≤25 mm.

[0043] Step S5, local horse frame expansion.

[0044] Specifically, two rounds of local horse rack expansion are performed, and each round of forging is heated to 435°C. Only the part of the horse rack expansion barrel 1 blank located between the outer sides of the two material distribution grooves 2 drives the inner and outer diameters of the flanges 11 at both ends of the barrel 1 blank to grow together. In the local horse rack expansion step, the hydraulic press pressing speed is 15mm / s, and the single hammer pressing amount is ≤25mm.

[0045] Step S6, machining.

[0046] Specifically, the forging is machined to a set size. Flanges 11 are machined at both ends of the outer side of the cylinder 1, and inner ribs 12 are machined on the inner side.

[0047] Step S7, solid solution.

[0048] Specifically, heat to 474°C and keep warm for 8 hours, water cool, water temperature is 40°C, and the water entry time interval is ≤15s.

[0049] Step S8, time limit.

[0050] Specifically, primary aging: heating to 110°C and keeping warm for 8 hours, then immediately raising the temperature for secondary aging. Secondary aging: heating to 165°C and keeping warm for 10 hours, then air cooling.

[0051] Second embodiment:

[0052] A production process for an ultra-high strength special-shaped barrel comprises the following steps:

[0053] Step S1, forging and punching.

[0054] Specifically, the weight percentage of each chemical element in the forging is: Si: 0.06%; Fe: 0.11%; Cu: 1.68%; Mn: 0.02%; Mg: 2.8%; Cr: 0.2%; Zn: 5.8%; Ti: 0.04%; other elements: single ≤ 0.05%, total ≤ 0.15%; the balance is Al.

[0055] Four fire-forgings were performed, and each fire forging was heated to 425°C. The process of chamfering, upsetting height, correcting bending, chamfering, upsetting width and correcting bending was repeated several times until the blank reached the set length, and then rounded, flattened and punched. In the forging step, the hydraulic press pressing speed was 10 mm / s, and the inner circle of the barrel 1 blank was machined after punching.

[0056] Step S2, expanding the hole of the horse frame.

[0057] Specifically, two rounds of horse rack expansion are carried out, each round of forging is heated to 425°C, and the pressing speed is 10mm / s.

[0058] Step S3, processing the material distribution trough 2.

[0059] Specifically, the material distribution grooves 2 are symmetrically arranged near the two ends of the outer side of the cylinder 1. The cross section of the material distribution groove 2 is a triangle. The outer angle α of the outer side of the triangle is 94°, the outer angle β of the inner side of the triangle is 140°, and the depth is 70 mm.

[0060] Step S4, lengthening the local mandrel.

[0061] Specifically, two fires of partial mandrel drawing are performed, and each fire is heated to 425° C. to draw only the portion of the barrel 1 blank located between the outer sides of the two dividing grooves 2. In the partial mandrel drawing step, the hydraulic press has a pressing speed of 10 mm / s, and the single hammer pressing amount is ≤25 mm.

[0062] Step S5, local horse frame expansion.

[0063] Specifically, three fires of local horse rack expansion are performed, and each fire is heated to 425°C. Only the part of the horse rack expansion barrel 1 blank located between the outer sides of the two material distribution grooves 2 drives the inner and outer diameters of the flanges 11 at both ends of the barrel 1 blank to grow together. In the local horse rack expansion step, the hydraulic press pressing speed is 10mm / s, and the single hammer pressing amount is ≤25mm.

[0064] Step S6, machining.

[0065] Specifically, the forging is machined to a set size. Flanges 11 are machined at both ends of the outer side of the cylinder 1, and inner ribs 12 are machined on the inner side.

[0066] Step S7, solid solution.

[0067] Specifically, heat to 464°C and keep warm for 8 hours, water cool, water temperature is 35°C, and the water entry time interval is ≤15s.

[0068] Step S8, time limit.

[0069] Specifically, primary aging: heating to 105°C and keeping warm for 8 hours, then immediately raising the temperature for secondary aging. Secondary aging: heating to 160°C and keeping warm for 10 hours, then air cooling.

[0070] Third embodiment:

[0071] A production process for an ultra-high strength special-shaped barrel comprises the following steps:

[0072] Step S1, forging and punching.

[0073] Specifically, the weight percentage of each chemical element in the forging is: Si: 0.06%; Fe: 0.11%; Cu: 1.68%; Mn: 0.02%; Mg: 2.8%; Cr: 0.2%; Zn: 5.8%; Ti: 0.04%; other elements: single ≤ 0.05%, total ≤ 0.15%; the balance is Al.

[0074] Two fires were forged, and each fire was heated to 445°C. The process of chamfering, upsetting height, correcting bending, chamfering, upsetting width and correcting bending was repeated several times until the blank reached the set length, and then rounded, flattened and punched. In the forging step, the hydraulic press had a downward speed of 20 mm / s, and the inner circle of the barrel 1 blank was machined after punching.

[0075] Step S2, expanding the hole of the horse frame.

[0076] Specifically, one fire of horse rack expansion is carried out, each fire of forging is heated to 445°C, and the pressing speed is 20mm / s.

[0077] Step S3, processing the material distribution trough 2.

[0078] Specifically, the outer side of the cylinder 1 is symmetrically provided with distribution grooves 2 near both ends. The cross section of the distribution groove 2 is a triangle. The outer angle α of the outer side of the triangle is 100°, the outer angle β of the inner side of the triangle is 160°, and the depth is 100 mm.

[0079] Step S4, lengthening the local mandrel.

[0080] Specifically, one fire is performed for partial mandrel drawing, and each fire is heated to 445°C, and only the portion of the barrel 1 blank located between the outer sides of the two dividing grooves 2 is drawn. In the partial mandrel drawing step, the hydraulic press has a pressing speed of 20 mm / s, and the single hammer pressing amount is ≤25 mm.

[0081] Step S5, local horse frame expansion.

[0082] Specifically, one fire is performed for local horse rack expansion, and each fire is heated to 445°C. Only the part of the horse rack expansion barrel 1 blank located between the outer sides of the two dividing grooves 2 drives the inner and outer diameters of the flanges 11 at both ends of the barrel 1 blank to grow together. In the local horse rack expansion step, the hydraulic press pressing speed is 20mm / s, and the single hammer pressing amount is ≤25mm.

[0083] Step S6, machining.

[0084] Specifically, the forging is machined to a set size. Flanges 11 are machined at both ends of the outer side of the cylinder 1, and inner ribs 12 are machined on the inner side.

[0085] Step S7, solid solution.

[0086] Specifically, heat to 484°C and keep warm for 8 hours, water cool, water temperature is 45°C, and the water entry time interval is ≤15s.

[0087] Step S8, time limit.

[0088] Specifically, primary aging: heating to 115°C and keeping warm for 8 hours, then immediately raising the temperature for secondary aging. Secondary aging: heating to 170°C and keeping warm for 10 hours, then air cooling.

[0089] Comparative Example:

[0090] The material distribution trough is designed to be U-shaped, with the U-shaped opening facing outward and two sides perpendicular to the end surface. The rest is the same as the first embodiment.

[0091] Test example:

[0092] The special-shaped cylinder forgings prepared in the first embodiment, the first embodiment, the first embodiment and the comparative example were tested for physical and chemical properties. The results are shown in Tables 1 and 2.

[0093] Table 1 Forging hardness

[0094] First embodiment Second embodiment Third embodiment Comparative Example Lower flange 11 157 157 156 168 Body 1 165 169 166 164 Body 2 165 168 168 158 Body 3 160 164 164 156 Body 4 156 154 154 158 Barrel 5 164 157 156 157 Barrel 6 166 156 157 157 Body 7 169 162 156 159 Barrel 8 158 165 164 162 Upper flange 11 165 159 155 159

[0095] Table 2

[0096]

[0097]

[0098] like Figure 7 As shown in the microstructure, it can be seen that the grain size of the special-shaped cylinder forgings obtained in the first embodiment is small, no burning is seen, and the crystal phase has no obvious aggregation. Figure 8 As shown, the low-magnification structure of the special-shaped cylinder forgings produced in the first embodiment is uniform without obvious coarse grains.

[0099] like Figure 5 As shown in the figure, after the billet with a U-shaped material distribution trough is stretched, a large amount of the middle material is accumulated on the flanges on both sides, and the inner circle of the flange is obviously trumpet-shaped. Figure 6 As shown, the material distribution trough of the embodiment of the present invention can reduce the accumulation of the middle material at the outer edges on both sides and improve the utilization rate.

[0100] It can be seen from the table that the overall performance of the special-shaped barrel forgings prepared in the comparative example is lower than that of the special-shaped barrel forgings prepared in the embodiment of the present invention. The special-shaped barrel forgings prepared in the embodiment of the present invention obtain uniform structure and excellent tensile strength, yield strength and elongation after heat treatment.

[0101] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0102] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A process for producing ultra-high strength special-shaped tubes, characterized in that: The following steps are involved: Prepare barrel blanks according to size; Processing of material distribution trough: The material distribution troughs are symmetrically opened near both ends of the outer side of the cylinder. The cross section of the material distribution trough is a triangle. The outer angle of the outer side of the triangle is 94°~100°, and the outer angle of the inner side of the triangle is 140°~160°; Partial mandrel drawing: 1 to 2 times, each time forging and heating to 425-445℃, only the part of the barrel blank located between the outsides of the two dividing grooves is drawn; Partial horse rack expansion: 1 to 3 fires, each fire is forged and heated to 425-445℃. Only the part of the horse rack expansion barrel blank located between the outer sides of the two dividing grooves 2 drives the inner and outer diameters of the flanges at both ends of the barrel blank to grow together.

2. The process for producing ultra-high strength special-shaped barrels according to claim 1, characterized in that: The outer angle of the outer side of the triangle of the material distribution trough is 97°, the outer angle of the inner side of the triangle is 150°, and the depth is 70-100mm.

3. The process for producing ultra-high strength special-shaped barrels according to claim 1, characterized in that: In the local mandrel lengthening step, the hydraulic press pressing speed is 10-20mm / s, and the single hammer pressing amount is ≤25mm; in the local horse rack reaming step, the hydraulic press pressing speed is 10-20mm / s, and the single hammer pressing amount is ≤25mm.

4. The process for producing ultra-high strength special-shaped barrels according to claim 1, characterized in that: The step of preparing the barrel blank according to the size comprises: Reforging and punching: 2 to 4 times, heating to 425-445℃ for each forging, and repeating the process of chamfering, upsetting height, correcting bending, chamfering, upsetting width and correcting bending for several times until the blank reaches the set length, and then rolling, flattening the end surface and punching; Horse frame expansion: 1 to 2 fires, each fire is heated to 425-445℃, and the pressing speed is 10-20mm / s.

5. The process for producing ultra-high strength special-shaped barrels according to claim 4, characterized in that: In the forging step, the hydraulic press has a pressing speed of 10 to 20 mm / s, and the inner circle of the barrel blank is machined after punching.

6. The process for producing ultra-high strength special-shaped barrels according to claim 1, characterized in that: After the step of local horse frame reaming, the step further includes: Machining: machining the forging to set dimensions; Solution treatment: Heat to 464-484℃ and keep warm for 8h, water cooling, water temperature 35-45℃, water immersion time interval ≤15s.

7. The process for producing ultra-high strength special-shaped barrels according to claim 1, characterized in that: After the solid solution step, the step further includes: Primary aging: heat to 105-115℃ and keep warm for 8h, then immediately raise the temperature for secondary aging; Secondary aging: heat to 160-170℃ and keep warm for 10h, then air cool.

8. The process for producing ultra-high strength special-shaped barrels according to claim 1, characterized in that: The weight percentage of each chemical element in the forging is: Si: 0.06%; Fe: 0.11%; Cu: 1.68%; Mn: 0.02%; Mg: 2.8%; Cr：0.2％； Zn: 5.8%; Ti: 0.04%; Other elements: individual ≤ 0.05%, total ≤ 0.15%; the balance is Al.

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