Zip-top can body aluminum alloy strip suitable for being rolled by single-stand cold rolling mill and preparation method

Abstract

According to the aluminum alloy strip suitable for being rolled by the single-stand cold rolling mill and used for the ring-pull can body and the preparation method, on the basis of 3104 aluminum alloy, the consumption of Si, Cu and Mn elements is reduced, the proportion of silicon iron is reduced, in other words, the target value of the Si element content is reduced to 0.2% from 0.25%, the target value of the Cu element content is reduced to 0.17% from 0.21%, and the target value of the Mn element content is reduced to 0.86% from 0.905%; the mass ratio of Si to Fe is controlled to be less than 47%; and meanwhile, the finish rolling temperature of the cold rolling mill is increased to be larger than or equal to 160 DEG C, so that the size of a second-phase metal compound is reduced, precipitated phase coarsening is weakened, and the physical performance of the aluminum alloy strip is stabilized. The aluminum alloy strip is suitable for the rolling requirement of a single-stand cold rolling mill, the produced aluminum alloy strip for the tank body material can meet the use requirements of downstream customers for tank making, and the deep drawability, the mechanical property and the tank breakage rate are obviously improved. And meanwhile, the production capacity of a single-stand cold rolling mill can be better utilized and exerted through preparation of the aluminum alloy strip, and the increasing requirement for the yield of the aluminum plate strip in the zip-top can body market is met.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of non-ferrous metal processing and relates to an aluminum alloy strip for a can body of a pop can suitable for rolling by a single-stand cold rolling mill and a preparation method. BACKGROUND

[0002] The pop can is widely used in the packaging of beer, carbonated beverages, fruit juice and other food due to its convenient carrying, safe use, recyclable value and other excellent performances.

[0003] The preparation material of the pop can includes an aluminum alloy strip and tinplate, and the aluminum alloy strip is a commonly used material for preparing the can body of the pop can. The 3104 aluminum alloy belongs to the Al-Mn-Mg series aluminum alloy and is the largest single output rolled aluminum alloy in the world, which is mainly used for manufacturing the can body of the pop can and has the characteristics of high strength, good toughness, strong corrosion resistance and good deep drawing formability. In addition, the 3104 aluminum alloy plate also has low anisotropy and earing rate, which is beneficial to being used as a deep drawing can.

[0004] The 3104 aluminum alloy will pass through a cold rolling process in the process of preparing the pop can, and the processing process of the process is generally divided into continuous rolling mill rolling and single-stand rolling. Compared with the single-stand, the continuous rolling mill device has higher control technology content and production efficiency. In addition, in the downstream can manufacturing use aspect, for the same thickness, the aluminum material produced by the continuous rolling mill device has better performance in the deep drawing property, can breaking rate and other use performances in the can manufacturing use process. Therefore, the 3104 aluminum alloy is more suitable for the continuous rolling mill rolling, and the mechanical properties of the 3104 aluminum alloy prepared by the single-stand rolling are poor. Based on this, it is necessary to provide a new aluminum alloy strip for the can body of the pop can to improve the performance of the aluminum alloy strip for the can body of the pop can rolled by the single-stand cold rolling mill. SUMMARY

[0005] The application aims to provide an aluminum alloy strip for a can body of a pop can suitable for rolling by a single-stand cold rolling mill and a preparation method, so as to solve the problem of poor mechanical properties of the 3104 aluminum alloy prepared by the single-stand rolling.

[0006] To achieve the above-mentioned purpose, the application adopts the following technical scheme: The application provides an aluminum alloy strip for a can body of a pop can suitable for rolling by a single-stand cold rolling mill, the content of each element of the aluminum alloy strip is as follows in terms of mass percentage: Si 0.1873-0.1944%, Fe 0.417-0.4281%, Cu 0.1675-0.2122%, Mn 0.8425-0.9171%, Mg 1.1881-1.253%, total impurities ≤0.15%, and the rest is Al; and the mass ratio of Si and Fe is less than 47%.

[0007] In the application, on the basis of 3104 aluminum alloy, the amounts of Si, Cu and Mn elements are reduced, the proportion of silicon iron is reduced, that is, the target value of Si element content is reduced from 0.25% to 0.2%, the target value of Cu element content is reduced from 0.21% to 0.17%, the target value of Mn element content is reduced from 0.905% to 0.86%, and the mass ratio of Si and Fe is controlled to be less than 47%; meanwhile, the final rolling temperature of the cold rolling mill is increased to be greater than or equal to 160 DEG C, so as to reduce the size of the second phase metal compound, weaken the coarsening of the precipitated phase, and stabilize the physical properties of the aluminum alloy strip.

[0008] More preferably, the aluminum alloy strip contains, in terms of mass percentage, Si 0.1873%, Fe 0.4225%, Cu 0.1675%, Mn 0.8425%, Mg 1.1881%, total impurities 0.05%, and the rest is Al.

[0009] In addition, the application provides a preparation method of the aluminum alloy strip for can body of a pop can, which is suitable for rolling of a single stand cold rolling mill, and the method comprises the following steps: (1) melting: ingredients of the aluminum alloy strip are prepared according to the element content, and the raw materials are successively melted and refined at 750-760 DEG C and 740-750 DEG C, and the liquid after refining is cast into an ingot under the conditions that the temperature is 690-700 DEG C, the casting speed is 60 mm / min, and the water temperature is 20-30 DEG C; (2) sawing and milling: the head of the ingot is sawed by 200 mm, the upper and lower surfaces are milled by 10 mm, and the tail is not sawed; (3) soaking: the ingot is heated at 600 DEG C for 3 h and then heated at 550 DEG C for 1 h, so as to realize staged soaking; (4) hot rolling: the ingot is hot-rolled according to a 1+4 hot continuous rolling process, the thickness and the temperature of the hot rolling intermediate blank are 30 mm and 475 DEG C respectively, the finished product thickness is 2.1-2.3 mm, the convexity rate is 0.3±0.2%, the wedge rate is ±0.2%, and the hot rolling coiling temperature is 340-350 DEG C; (5) cold rolling: the hot-rolled ingot is rolled to a thickness of 0.9-1.22 mm by using a single stand cold rolling mill, and then intermediate trimming is performed, and the minimum trimming amount of the intermediate trimming is 2*10 mm, and the trimming tension is 28 N / mm 2 ; after trimming, the ingot is rolled to a thickness of 0.25-0.26 mm by two passes at a speed of 800-1100 m / min, the temperature of the first pass before forming the finished product is 120-140 DEG C, the final rolling temperature is greater than or equal to 160 DEG C, and the finished product is formed; (6) trimming: trimmed to the required finished product width.

[0010] The application has the following beneficial effects: (1) In the present application, on the basis of 3104 aluminum alloy, the amounts of Si, Cu and Mn elements are reduced, the ratio of silicon iron is reduced, that is, the target value of Si element content is reduced from 0.25% to 0.2%, the target value of Cu element content is reduced from 0.21% to 0.17%, the target value of Mn element content is reduced from 0.905% to 0.86%, and the mass ratio of Si and Fe is controlled to be less than 47%; at the same time, the final rolling temperature of the cold rolling mill is increased to be greater than or equal to 160℃, so as to reduce the size of the second phase metal compound, weaken the coarsening of the precipitated phase, and stabilize the physical properties of the aluminum alloy strip.

[0011] (2) The aluminum alloy strip is suitable for rolling requirement of single stand cold rolling mill, the produced can body material aluminum alloy strip can meet the use requirement of downstream customers for can making, the deep drawing property and mechanical property are obviously improved, the can breaking rate is reduced. At the same time, the preparation of the aluminum alloy strip can better utilize the production capacity of the single stand cold rolling mill, and meet the increasing production requirement of aluminum plate strip for the market of easy open can can body. DETAILED DESCRIPTION

[0012] The technical scheme of the present application will be further explained and described through specific embodiments.

[0013] Embodiment 1 The present application provides an easy open can can body aluminum alloy strip suitable for rolling of single stand cold rolling mill, the aluminum alloy strip is rolled by single stand cold rolling mill, and the preparation method is as follows: (1) Melting: the aluminum alloy strip is prepared according to the element content mass percentage of Si 0.1944%, Fe 0.4281%, Cu 0.1743%, Mn 0.8667%, Mg 1.2049%, total impurities 0.05%, and the rest is Al, the raw materials are successively melted and refined at 750℃ and 740℃, and the liquid after refining is cast into an ingot under the conditions of a temperature of 690℃, a casting speed of 60mm / min and a water temperature of 20℃; (2) Sawing and milling: the head of the ingot is sawed by 200mm, the upper and lower surfaces are milled by 10mm, and the tail is not sawed; (3) Soaking: the ingot is heated at 600℃ for 3h and then heated at 550℃ for 1h to realize staged soaking; (4) Hot rolling: the ingot is hot rolled according to 1+4 hot continuous rolling process, the thickness and temperature of the hot rolling intermediate blank are 30mm and 475℃ respectively, the finished product thickness is 2.1-2.3mm, the convexity rate is 0.3±0.2%, the wedge rate is ±0.2%, and the hot rolling coiling temperature is 340℃; (5) Cold rolling: the hot rolled ingot is rolled to a thickness of 0.9mm by single stand cold rolling mill, and then intermediate trimming is performed, and the minimum trimming amount of intermediate trimming is 2×10mm, and the trimming tension is 28N / mm 2; after trimming, through two passes of tandem rolling to a thickness of 0.2 mm and a speed of 800 m / min, forming a finished product with a pass temperature of 130 ℃ and a finish rolling temperature of 162.35 ℃; (6) trimming: trimmed to the required finished product width.

[0014] Example 2 The example of the present application provides an aluminum alloy strip for a can body of a pop can, which is suitable for rolling by a single-stand cold rolling mill. The aluminum alloy strip is prepared by the method of example 1, and only the raw material for preparing the aluminum alloy strip comprises, by mass percent, Si 0.1873%, Fe 0.4225%, Cu 0.1675%, Mn 0.8425%, Mg 1.1881%, total impurities 0.10%, and the rest is Al. The finish rolling temperature is 161.69 ℃.

[0015] Example 3 The example of the present application provides an aluminum alloy strip for a can body of a pop can, which is suitable for rolling by a single-stand cold rolling mill. The aluminum alloy strip is prepared by the method of example 1, and only the raw material for preparing the aluminum alloy strip comprises, by mass percent, Si 0.1892%, Fe 0.4181%, Cu 0.1747%, Mn 0.8423%, Mg 1.2022%, total impurities 0.15%, and the rest is Al. The finish rolling temperature is 160.7 ℃.

[0016] Comparative Example 1 The comparative example of the present application provides an aluminum alloy strip for a can body of a pop can, which is prepared by a three-stand tandem rolling mill. The aluminum alloy strip is prepared by the method of example 1, and only the raw material for preparing the aluminum alloy strip comprises, by mass percent, Si 0.2518%, Fe 0.4346%, Cu 0.2146%, Mn 0.9056%, Mg 1.263%, total impurities 0.15%, and the rest is Al. The passes are 2.1-0.835-0.438-0.250, without intermediate trimming, and the finish rolling temperature is 133.06 ℃.

[0017] Comparative Example 2 The comparative example of the present application provides an aluminum alloy strip for a can body of a pop can, which is prepared by a three-stand tandem rolling mill. The aluminum alloy strip is prepared by the method of comparative example 1, and only the raw material for preparing the aluminum alloy strip comprises, by mass percent, Si 0.2425%, Fe 0.417%, Cu 0.2122%, Mn 0.9171%, Mg 1.253%, total impurities 0.15%, and the rest is Al. The finish rolling temperature is 133.64 ℃.

[0018] Comparative Example 3 The application provides an aluminum alloy strip for a zip-top can body, which is rolled by a three-stand rolling mill, and the preparation method is the same as that in the comparative example 1, and only the raw material of the aluminum alloy strip comprises, in mass percentage, Si 0.2509%, Fe 0.4198%, Cu 0.2066%, Mn 0.9064%, Mg 1.2287%, total impurities 0.15%, and the rest is Al; and the final rolling temperature is 133.98℃.

[0019] The raw material of the aluminum alloy strip, the mass ratio of Si and Fe, and the final rolling temperature of the aluminum alloy strips in the examples 1-3 and the comparative examples 1-3 are listed to form Table 1.

[0020] Table 1: Raw material of the aluminum alloy strip, mass ratio of Si and Fe, and final rolling temperature of the aluminum alloy strips in the examples 1-3 and the comparative examples 1-3 The tensile strength, yield strength, elongation, and earing rate of the aluminum alloy strips prepared in the examples 1-3 and the comparative examples 1-3 are respectively detected to obtain Table 2.

[0021] Table 2: Tensile strength, yield strength, elongation, and earing rate detection results of the aluminum alloy strips As shown in Table 2, the aluminum alloy strips prepared in the examples 1-3 can meet the requirements of the mechanical properties, elongation, and earing rate of the can body, ensure the deep drawing requirement of the subsequent can material processing plant, and have good guarantee for reducing the can breaking rate, meeting the pressure bearing of the can body, and maintaining good forming performance. In addition, compared with the aluminum alloy strips produced by the continuous rolling mill in the comparative examples 1-3, the elongation of the aluminum alloy strips produced by the single-stand cold rolling mill in the examples 1-3 is better, and the use requirement can be better met. Therefore, the aluminum alloy strips in the examples can better utilize the production capacity of the single-stand cold rolling mill, meet the increasing demand for aluminum plate strip production of the zip-top can body market, and have a positive effect on promoting the development of the aluminum plate strip processing industry.

[0022] The above only describes the preferred embodiments of the application and is not intended to limit the application. The application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. An aluminum alloy strip for can bodies suitable for rolling on a single-stand cold rolling mill, characterized in that: The content of each element in the aluminum alloy strip includes, by mass percentage, Si 0.1873-0.1944%, Fe 0.417-0.4281%, Cu 0.1675-0.2122%, Mn 0.8425-0.9171%, Mg 1.1881-1.253%, total impurities ≤0.15%, and the rest is Al; and the mass ratio of Si to Fe is less than 47%.

2. The aluminum alloy strip for can bodies suitable for rolling on a single-stand cold rolling mill according to claim 1, characterized in that: The content of each element in the aluminum alloy strip includes Si0.1873%, Fe0.4225%, Cu0.1675%, Mn0.8425%, Mg1.1881% in terms of mass percentage, total impurities of 0.10%, and the rest is Al.

3. A method for preparing an aluminum alloy strip for can bodies suitable for rolling on a single-stand cold rolling mill, characterized in that: include: Melting: The aluminum alloy strip is batched, melted, refined according to the content of each element, and cast into ingots; Sawing and milling: sawing the head of the ingot by 200 mm, milling the upper and lower surfaces by 10 mm, and not sawing the tail; Soaking: heating the ingot at 600°C for 3 hours and then at 550°C for 1 hour; Hot rolling: the ingot is hot rolled according to a 1+4 hot rolling process, and the thickness and temperature of the hot rolling intermediate billet are 30 mm and 475° C., respectively. The finished product has a thickness of 2.1-2.3 mm, a crown rate of 0.3±0.2%, a wedge rate of ±0.2%, and a hot rolling coiling temperature of 340-350° C.; Cold rolling: using a single-stand cold rolling mill to roll the hot-rolled ingot to a thickness of 0.9-1.22 mm, trimming the edges in the middle, and then rolling it through two passes of continuous rolling to a thickness of 0.25-0.26 mm to form a finished product; Trimming: Cut to finished width.

4. The method for preparing an aluminum alloy strip for can bodies suitable for rolling on a single-stand cold rolling mill according to claim 3, characterized in that: The minimum trimming amount of the middle trimming is 2×10mm, and the trimming tension is 28N / mm 2 .

5. The method for preparing an aluminum alloy strip for can bodies suitable for rolling on a single-stand cold rolling mill according to claim 3, characterized in that: The speed of the two-pass continuous rolling is 800-1100m / min.

6. The method for preparing an aluminum alloy strip for can bodies suitable for rolling on a single-stand cold rolling mill according to claim 3, characterized in that: The temperature of one pass before forming the finished product is 120-140℃, and the final rolling temperature is ≥160℃.

7. The method for preparing an aluminum alloy strip for can bodies suitable for rolling on a single-stand cold rolling mill according to claim 3, characterized in that: The melting, refining and casting temperatures are 750-760℃, 740-750℃ and 690-700℃ respectively.

8. The method for preparing an aluminum alloy strip for can bodies suitable for rolling on a single-stand cold rolling mill according to claim 3, characterized in that: The casting speed is 60 mm / min and the water temperature is 20-30°C.

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