Process for manufacturing a 7-series aluminum alloy puncture-resistant riot shield

Abstract

The present application relates to a kind of 7 series aluminum alloy penetration-resistant riot shield manufacturing process, step 1 is produced according to the aluminum alloy component described above Preparation aluminum alloy ingot;Step 2, aluminum alloy ingot is carried out homogenization annealing after starting casting, annealing temperature uses two-stage homogenization, the first-stage homogenization temperature is 300-400 DEG C, the second-stage homogenization temperature is 400-500 DEG C;Step 3, hot rolling, cold rolling production, the finished product thickness is 5.0±0.5mm after hot rolling, the final rolling temperature of hot rolling production is controlled to be above 300 DEG C, and the finished product thickness is controlled to be 1.7-2.0mm in cold rolling production;Step 4, after breaking down and cold rolling, carry out intermediate annealing, the annealing temperature is controlled to be 380-450 DEG C, the time is 4-12 hours, and the power before and after medium fire is controlled to be 30-50%;The present application obtains high-strength aluminum alloy riot shield by adjusting process flow, to replace the common steel, polymer shield in the existing market.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of non-ferrous metals, and particularly relates to a manufacturing process of a 7-series aluminum alloy puncture-resistant riot shield. BACKGROUND

[0002] The aluminum alloy riot shield is a special-purpose protective preparation, which is mainly used in law enforcement departments and military operations to protect users from violent conflicts and potential dangers. The development of light-weight high-strength aluminum alloy is conducive to improving the safety and efficiency of law enforcement personnel during task execution and facilitating the maintenance of public order.

[0003] The aluminum alloy riot shield is an important physical protective equipment for law enforcement personnel during task execution, which can effectively resist various attacking weapons. It not only provides safety protection for law enforcement personnel, but also plays a key role in maintaining public order and controlling crowds, making law enforcement actions more efficient and orderly.

[0004] However, most of the riot shields on the market are made of steel or high polymer materials, and the use of aluminum alloy shields is less and most of them have a thickness of more than 3.0 mm to achieve puncture resistance. Generally, such thick shields are heavy, making it more difficult to carry and operate, and also increasing the fatigue of the user. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a manufacturing process of a 7-series aluminum alloy puncture-resistant riot shield. The present application improves the puncture resistance of conventional aluminum alloy shields by adjusting the process, and the improvement of puncture resistance under the same thickness also achieves the effect of light weight.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] The manufacturing process of the 7-series aluminum alloy puncture-resistant riot shield, wherein the aluminum alloy composition comprises, by mass percentage: Si 0.01-0.10%, Fe 0.05-0.15%, Cu 1.2-2.0%, Mn 0.01-0.1%, Mg 2.5-2.9%, Cr 0.18-0.21%, Zn 5.5-6.1%, Ti 0.02-0.03%, Zr 0.01-0.02%, and the balance being Al and other unavoidable impurity elements, and the total content of Si and Fe elements is not higher than 0.2%.

[0008] The manufacturing process of the 7-series aluminum alloy puncture-resistant riot shield specifically comprises the following steps:

[0009] Step 1. Produce and prepare aluminum alloy ingots according to the aforementioned aluminum alloy composition;

[0010] Step 2. The aluminum alloy ingot is homogenized after casting, and the homogenization temperature uses double-stage homogenization, the first-stage homogenization temperature is 300-400℃, and the second-stage homogenization temperature is 400-500℃;

[0011] Step 3. Hot rolling and cold rolling production, the finished product thickness after hot rolling is 4.0-5.0mm, and the final rolling temperature of the hot rolling production is controlled to be above 300℃, and the finished product thickness of the cold rolling production is controlled to be 1.7-2.0mm;

[0012] Step 4. Intermediate annealing after breakdown cold rolling, the annealing temperature is controlled to be 380-450℃, the time is 4-12 hours, and the power before and after the medium fire is controlled to be 30-50%;

[0013] Step 5. Solid solution in the air cushion type continuous annealing furnace, the solid solution temperature is 460-480℃, and the coiled material is ensured to be at the solid solution temperature for not less than 120s-150s;

[0014] Step 6. Artificial aging temperature is set to be 125-140℃, and the time is 8-24 hours;

[0015] The 7075 aluminum alloy puncture-resistant anti-riot shield strip prepared according to the above steps has a tensile strength of not less than 530MPa, a yield strength of not less than 460MPa, and an elongation of not less than 10%.

[0016] Preferably, the first-stage homogenization treatment temperature in step (2) is 350±5℃, the holding time is 2-6h, the second-stage homogenization temperature is 470±5℃, and the holding time is 24-40h.

[0017] Preferably, in step (3), the homogenized aluminum alloy ingot is first hot rough rolled to 22-24mm at 420℃, and then hot finished to 4.0-5.0mm.

[0018] Preferably, in step (4), the intermediate annealing temperature is controlled to be 400-420℃, and the time is 6-10 hours.

[0019] Preferably, in step (5), the solid solution temperature is 470-475℃, and the solid solution time is 120-150s.

[0020] Preferably, the amount of cooling water in the air cushion type continuous annealing furnace is controlled by water pressure and nozzle row number, wherein the water pressure is controlled to be 1.0-4.0bar, and the nozzle row number is 0-4 rows.

[0021] Preferably, the ingot is homogenized at 400-420 DEG C for 2h, and then hot-rolled to obtain a hot-rolled coil with a thickness of 4.0-5.0mm; after cold rolling to 1.7-2.0mm, intermediate annealing is not performed; then solid solution treatment is performed by using a gas cushion type continuous annealing line, the solid solution temperature is 460-475 DEG C, and the solid solution time is 120-150s; after solid solution, water cooling is performed by opening 4 rows of hard water nozzles with a water pressure of 1.5bar; the aging temperature is 125-140 DEG C, and the aging time is controlled to be 20h.

[0022] Preferably, the ingot is homogenized at 400-420 DEG C for 2h, and then hot-rolled to obtain a hot-rolled coil with a thickness of 4.0-5.0mm; after cold rolling to 1.7-2.0mm, intermediate annealing is not performed; then solid solution treatment is performed by using a gas cushion type continuous annealing line, the solid solution temperature is 460-475 DEG C, and the solid solution time is 120-150s; after solid solution, water cooling is performed by opening 4 rows of hard water nozzles with a water pressure of 1.5bar; the aging temperature is 125-140 DEG C, and the aging time is controlled to be 20h.

[0023] Preferably, the ingot is homogenized at 400-420 DEG C for 2h, and then hot-rolled to obtain a hot-rolled coil with a thickness of 4.0-5.0mm; after cold rolling to 1.7-2.0mm, intermediate annealing is not performed; then solid solution treatment is performed by using a gas cushion type continuous annealing line, the solid solution temperature is 460-475 DEG C, and the solid solution time is 120-150s; after solid solution, water cooling is performed by opening 4 rows of hard water nozzles with a water pressure of 1.5bar; the aging temperature is 125-140 DEG C, and the aging time is controlled to be 20h.

[0024] The present application has the beneficial effects that:

[0025] The 7-series aluminum alloy anti-penetration riot shield manufacturing process of the present application can obtain a high-strength aluminum alloy riot shield by adjusting the process flow, in particular by adjusting the ingot homogenization temperature, hot rolling and cold rolling process parameters, intermediate annealing or not, solid solution quenching parameters, artificial aging time and the like, so as to replace the common steel and high polymer shields in the market; the strength of the shield is much higher than that of the 5-series and 6-series aluminum alloy shields under the same thickness, the weight of the shield can be greatly reduced, and the lightweight purpose is achieved; and the cooling speed of the aluminum material after solid solution improves the size of the second phase at the grain boundary, so as to improve the anti-penetration performance of the riot shield. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is the grain camera image under a microscope of each embodiment of the present application;

[0027] Figure 2 is the grain boundary phase camera image under a microscope of each embodiment of the present application. DETAILED DESCRIPTION

[0028] The application will be further described in conjunction with the accompanying drawings and examples.

[0029] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0030] The process for manufacturing the 7-series aluminum alloy puncture-resistant riot shield specifically comprises the following steps:

[0031] Step 1. Production of aluminum alloy ingot;

[0032] Step 2. After the aluminum alloy ingot is cast, homogenization annealing is performed, and two-stage homogenization is used for the annealing temperature, the first-stage homogenization temperature is 300-400℃, and the second-stage homogenization temperature is 400-500℃;

[0033] Step 3. Hot rolling and cold rolling production, the finished product thickness after hot rolling is 4.0-5.0mm, and the final rolling temperature of the hot rolling production is controlled to be above 300℃, and the finished product thickness of the cold rolling production is controlled to be 1.7-2.0mm;

[0034] Step 4. After the breakdown cold rolling, intermediate annealing is performed, the annealing temperature is controlled to be 380-450℃, the time is 4-12 hours, and the power before and after the medium fire is controlled to be 30-50%;

[0035] Step 5. Solid solution is performed in a gas cushion type continuous annealing furnace, the solid solution temperature is 460-475℃, and the time of the coiled material at the solid solution temperature is ensured to be not less than 120s-150s;

[0036] Step 6. The artificial aging temperature is set to be 125-140℃, and the time is 8-24 hours;

[0037] The 7075 aluminum alloy puncture-resistant riot shield strip prepared according to the above steps has a tensile strength of not less than 530MPa, a yield strength of not less than 460MPa, and an elongation of not less than 10%.

[0038] The aluminum alloy composition of the aluminum alloy ingot in step 1 is, by mass percentage: Si 0.01-0.10%, Fe 0.05-0.15%, Cu 1.2-2.0%, Mn 0.01-0.1%, Mg 2.5-2.9%, Cr 0.18-0.21%, Zn 5.5-6.1%, Ti 0.02-0.03%, Zr 0.01-0.02%, and the balance is Al and other inevitable impurity elements, and the total content of Si and Fe elements is not higher than 0.2%.

[0039] The aluminum alloy composition of the specific aluminum alloy ingot is, by mass percent: Si 0.09%, Fe 0.08%, Cu 1.5%, Mn 0.06%, Mg 2.7%, Cr 0.20%, Zn 5.8%, Ti 0.02%, Zr 0.015%, and the balance being Al and other unavoidable impurity elements.

[0040] The first-stage homogenization treatment temperature in step (2) is 350±5°C, and the holding time is 2-6h, and the second-stage homogenization temperature is 470±5°C, and the holding time is 24-40h.

[0041] In step (3), the homogenized aluminum alloy ingot is first hot rough rolled to 22-24mm at 420°C, and then hot finished to 4.0-5.0mm.

[0042] In step (4), the intermediate annealing temperature is controlled at 400-420°C, and the time is 6-10h.

[0043] In step (5), the solid solution temperature is 460-475°C, and the solid solution time is 120-150s.

[0044] Preferably, the amount of cooling water in the air cushion continuous annealing furnace is controlled by water pressure and nozzle row number, wherein the water pressure is controlled at 1.0-2.0bar, and the nozzle row number is 0-2rows.

[0045] Example 1

[0046] After the ingot is homogenized, it is held at 420°C for 2h, and then hot rolled to obtain a hot-rolled coil with a thickness of 5.0mm; after breakdown cold rolling, intermediate annealing is performed, and then cold rolling is performed to 1.7-2.0mm; thereafter, solid solution treatment is performed using an air cushion continuous annealing line, the solid solution temperature is 460-475°C, and the solid solution time is 120-150s; after solid solution, water cooling is performed using 4rows of hard water nozzles opened, and the water pressure is 1.5bar; the aging temperature is 125-140°C, and the aging time is controlled at 20h.

[0047] Comparative Example 1

[0048] The aluminum alloy strip processing process shown in this example is: after the ingot is homogenized, it is held at 420°C for 2h, and then hot rolled to obtain a hot-rolled coil with a thickness of 4.0-5.0mm; cold rolling is performed to 1.7-2.0mm without intermediate annealing; thereafter, solid solution treatment is performed using an air cushion continuous annealing line, the solid solution temperature is 460-475°C, and the solid solution time is 120-150s; after solid solution, water cooling is performed using 4rows of hard water nozzles opened, and the water pressure is 1.5bar; the aging temperature is 125-140°C, and the aging time is controlled at 20h.

[0049] Example 2

[0050] The aluminum alloy strip processing process shown in this example is: after homogenization of the ingot, heat preservation at 420℃ for 2h, and then hot rolling to obtain hot rolled coils with a thickness of 4.0-5.0mm; cold rolling to 1.7-2.0mm without intermediate annealing; then solid solution treatment is carried out using a gas cushion type continuous annealing line, the solid solution temperature is 460-475℃, and the solid solution time is 120-150 seconds; after solid solution, water cooling is carried out by opening 2 rows of hard water nozzles with a water pressure of 1.5bar; the aging temperature is 125-140℃, and the aging time is controlled at 12 hours.

[0051] Example 3

[0052] The aluminum alloy strip processing process shown in this example is: after homogenization of the ingot, heat preservation at 420℃ for 2h, and then hot rolling to obtain hot rolled coils with a thickness of 4.0-5.0mm; cold rolling to 1.7-2.0mm without intermediate annealing; then solid solution treatment is carried out using a gas cushion type continuous annealing line, the solid solution temperature is 460-475℃, and the solid solution time is 120-150 seconds; after solid solution, water cooling is carried out by opening 2 rows of hard water nozzles with a water pressure of 1.5bar; the aging temperature is 125-140℃, and the aging time is controlled at 12 hours.

[0053] The following table is a comparison of the properties of each example

[0054]

[0055] The following table is a comparison of Example 1 and Comparative Example 1

[0056] .

[0057] In the above examples, 1. After the cold rolling breakdown pass, an intermediate annealing process is added to reset the cold rolling power adjustment grain size and microstructure morphology, adjust the grain size to 50-80μm, and the aspect ratio ≥5 can effectively improve the impact resistance of the material. The better the impact resistance of the aluminum alloy, the lower the possibility of puncture cracking.

[0058] 2. Adjust the water cooling speed after solid solution to directly change the state of the precipitated phase at the grain boundary. Under the condition of slow water cooling speed, coarse second phase is easily precipitated at the grain boundary, which is extremely easy to become a cracking propagation source and easily crack under puncture.

[0059] The advantages of the present application are:

[0060] 1. By adjusting the process, the size and morphology of the grain and grain boundary phase are adjusted to improve the puncture resistance of the shield;

[0061] 2. The improvement of puncture resistance under the same weight can appropriately thin the shield, achieving the effect of lightweight;

[0062] 3. The advantage of the present application is not only suitable for improving the penetration resistance of the shield, but also has universality, which can be used in other fields suitable for 7 series aluminum alloy.

[0063] The above preferred embodiments further illustrate the purpose, technical solutions and advantages of the present application. It should be understood that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A manufacturing process for a 7-series aluminum alloy puncture-resistant riot shield, characterized in that: The aluminum alloy composition, by mass percentage, is: Si 0.01-0.10%, Fe 0.05-0.15%, Cu 1.2-2.0%, Mn 0.01-0.1%, Mg 2.5-2.9%, Cr 0.18-0.21%, Zn 5.5-6.1%, Ti 0.02-0.03%, Zr 0.01-0.02%, with the balance being Al and other unavoidable impurity elements, and the total content of Si and Fe elements not exceeding 0.2%; including the following steps: Step 1. Prepare aluminum alloy ingots according to the aforementioned aluminum alloy composition; Step 2. After casting, the aluminum alloy ingot undergoes homogenization annealing. The annealing temperature uses a two-stage homogenization process, with the first-stage homogenization temperature being 300-400℃ and the second-stage homogenization temperature being 400-500℃. Step 3. Hot rolling and cold rolling production. The thickness of the finished product after hot rolling is 4.0-5.0 mm. The final rolling temperature of hot rolling production is controlled above 300℃. The thickness of the finished product in cold rolling production is controlled to be 1.7-2.0 mm. Step 4. After cold rolling, perform intermediate annealing at a temperature of 380-450℃ for 4-12 hours. The power before and after intermediate annealing should be controlled at 30-50%. Step 5. Solution treatment is performed in an air cushion continuous annealing furnace at a temperature of 460-480℃, and the solution treatment time of the roll material is not less than 100s-180s. Step 6. Set the artificial aging temperature to 125-140℃ and the time to 8-24 hours; The 7075 aluminum alloy puncture-resistant riot shield strip prepared according to the above steps has a tensile strength of not less than 530 MPa, a yield strength of not less than 460 MPa, and an elongation of not less than 10%.

2. The manufacturing process of the 7-series aluminum alloy puncture-resistant riot shield according to claim 1, characterized in that: In step (2), the first homogenization treatment temperature is 350±5℃ and the holding time is 2-6h, and the second homogenization temperature is 470±5℃ and the holding time is 24-40h.

3. The manufacturing process of the 7-series aluminum alloy puncture-resistant riot shield according to claim 1, characterized in that: In step (3), the homogenized aluminum alloy ingot is first hot rough rolled to 22-24 mm at 400-420℃, and then hot finish rolled to 4.0-5.0 mm.

4. The manufacturing process of the 7-series aluminum alloy puncture-resistant riot shield according to claim 1, characterized in that: In step (4), the intermediate annealing temperature is controlled at 400-420℃ for 6-10 hours.

5. The manufacturing process of the 7-series aluminum alloy puncture-resistant riot shield according to claim 1, characterized in that: In step (5), the solution temperature is 460-475℃ and the solution time is 120-150s.

6. The manufacturing process of the 7-series aluminum alloy puncture-resistant riot shield according to claim 5, characterized in that: The cooling water volume in the air cushion continuous annealing furnace is controlled by the water pressure and the number of nozzle rows, wherein the water pressure is controlled between 0 and 4.0 bar, and the number of nozzle rows is between 0 and 4.

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