JP4077997B2 - Manufacturing method of aluminum alloy hard plate for can lid - Google Patents

Description

【００４２】
【表２】

【００４３】
【表３】

【００４４】
表１〜表３において、この発明で規定する成分組成範囲内の合金を用いてこの発明の製造プロセス条件に従って製造した製造符号Ａ〜Ｃによる缶蓋材は、いずれも低耳率でかつ強度の異方性（最大耐力差）も小さいことが確認された。
【００４５】
一方製造符号Ｄ〜Ｆは、いずれも成分組成がこの発明の範囲内の合金を用いたが、製造プロセス条件がこの発明で規定する範囲を満たさなかった比較例である。具体的には、製造符号Ｄは、熱間圧延の最終パスの圧延速度が遅かった例であるが、この場合は耳率が高くなってしまった。また製造符号Ｅは、熱間圧延終了温度が低過ぎた例であるが、この場合は耳率が高くなってしまい、また最終焼鈍を行なわないために強度の異方性も大きくなってしまった。そしてまた製造符号Ｆは熱間圧延の最終パスの圧下率が小さ過ぎた例であるが、この場合は耳率が高くなってしまった。
【００４６】
さらに製造符号Ｇ，Ｈは成分組成がこの発明で規定する範囲を外れた比較合金を用いた例である。これらのうち、製造符号Ｇは｛Ｆｅ量（％）＋Ｍｎ量（％）｝／Ｓｉ量（％）の値が２３．３と高過ぎる合金Ｎｏ．５を用いた例であり、この場合は耳率が高くなってしまった。また製造符号Ｈは、Ｍｇ量が多過ぎる合金Ｎｏ．６を用いた例であるが、この場合は耳率が高くなってしまい、また最終焼鈍を行なわないために強度の異方性も大きくなってしまった。
【００４７】
【発明の効果】
この発明の缶蓋用アルミニウム合金硬質板の製造方法によれば、耳率が安定して低くかつ強度の異方性も少なく、さらには強度や成形性、引き裂き性（開缶性）等の缶蓋材に要求される一般的性能も優れた缶蓋材を確実に得ることができ、そのためこの発明の方法により得られた板を缶蓋に使用すれば、缶胴材との巻き締め加工の際において巻き締め不良が生じるおそれが少なく、また強度の異方性が少ないため缶を落下させた衝撃によりスコア部分から割れるおそれも少ないなど、優れた効果を発揮することができる。またこの発明の方法による缶蓋用アルミニウム合金硬質板は、Ｍｎを含有する系の合金を用いているため、消費量の多い５１８２合金缶蓋材や３００４合金缶胴材等のスクラップを利用することができ、したがってリサイクル性にも優れている。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing an aluminum can lid material, and particularly as an aluminum can lid material suitable for a steion tub type can lid for a negative pressure can that does not contain carbonic acid such as fruit juice, coffee, and tea. The present invention relates to a method for producing an aluminum can lid material having small anisotropy, low ear rate, and excellent recyclability.
[0002]
[Prior art]
In general, steion tab type aluminum can lids have high strength and good formability, good can openability (score tearability), excellent rivet workability, and excellent surface quality. Is required. Conventionally, as this kind of aluminum can lid material, 5000 series alloys (Al-Mg series alloys, Al-Mg-Mn series alloys) such as 5052 alloy and 5182 alloy are frequently used. In particular, as beverage cans that do not contain carbonic acid such as fruit juice, coffee, and tea, that is, can lid materials for negative pressure cans, Al-Mg-based 5052 alloy is often used.
[0003]
[Problems to be solved by the invention]
By the way, when attaching the can lid to the can body, it is necessary to wind the can lid around the edge of the can body. May occur. In addition, the can lid is generally score processed for opening the can, especially the steion tab type can lid, since the score processing rate is large, when the maximum proof stress difference in each direction with respect to the rolling direction is large, that is, When the strength anisotropy is large, there is a risk that the contents may leak due to a crack occurring from a low strength portion of the score portion due to an impact when the can is dropped.
[0004]
However, in the conventional aluminum can lid material, such an ear ratio and anisotropy of strength have not been sufficiently studied, so that it is possible to reliably prevent the occurrence of poor tightening, and at the time of a drop impact of the can It was still difficult to reliably and stably prevent the occurrence of cracks.
[0005]
In particular, recently, it has been desired to produce can lids for negative pressure cans using scraps of 5182 alloy can lid materials and 3004 alloy can body materials, which are highly consumed, and these 5182 alloys and 3004 alloys are In order to use these scrap materials as can lids for negative pressure cans, it is desirable to use alloys containing Mn as can lid materials for negative pressure cans. Various experiments for its development have been conducted, but the fact is that sufficient consideration has not been given to the anisotropy of the ear rate and strength as described above.
[0006]
This invention was made against the background of the above circumstances, and particularly as an aluminum can lid material suitable for a can lid for a negative pressure can of the steion tab method, the ear rate is stable and low, and the strength anisotropy The object of the present invention is to provide a method for producing a can lid material that is less in number and more excellent in recyclability.
[0007]
[Means for Solving the Problems]
In order to solve the problems as described above, the present inventors have conducted extensive experimental studies, and as a result, the component system of the aluminum alloy of the can lid material is basically an Al-Mg-Mn system, and the amount of Mg, Properly set the Mn amount, Fe amount, and Si amount, and properly regulate the mutual relationship between the Fe amount, Si amount, and Mn amount, and strictly regulate the manufacturing process conditions, particularly hot rolling conditions. By properly regulating the intermediate annealing conditions and the final cold rolling conditions after hot rolling, the can lid material can stably meet and meet the performance requirements of other can lid materials. Furthermore, it was found that the anisotropy of the strength can be stably reduced by appropriately regulating the final annealing conditions in the can lid manufacturing process, and the present invention has been made.
[0008]
Specifically, the manufacturing method of the aluminum alloy hard plate for can lids of the invention of claim 1 is Mg 0.8 to 3.0%, Mn 0.01 to 1.2%, Fe 0.10 to 0.50%, An alloy containing 0.05 to 0.40% Si, {Fe amount (%) + Mn amount (%)} / Si amount (%) is 20 or less, and the balance is Al and inevitable impurities is used as a raw material. In the hot rolling of the ingot, the hot rolling start temperature is set within the range of 400 to 580 ° C., the rolling speed in the pass 2 passes before the final pass is 50 m / min or more, and the pass before the final pass 1 pass. The rolling speed in the second pass is 100 m / min or more, the rolling speed in the final pass is 150 m / min or more, and the rolling reduction in the final pass is in the range of 20 to 70%. Finished and rolled The hot-rolled sheet is heated to a temperature in the range of 320 to 550 ° C. and subjected to intermediate annealing by continuous annealing without holding or holding for 10 minutes or less, and finally cold-rolled at a rolling rate of 40% or more. It is characterized by performing.
[0009]
Moreover, the manufacturing method of the aluminum alloy hard plate for can lids of invention of Claim 2 is Mg0.8-3.0%, Mn0.01-1.2%, Fe0.10-0.50%, Si0.05- An ingot containing 0.40% and having {Fe amount (%) + Mn amount (%)} / Si amount (%) of 20 or less and the balance being Al and inevitable impurities When hot rolling is performed, the hot rolling start temperature is set within the range of 400 to 580 ° C., the rolling speed in the pass 2 passes before the final pass is 50 m / min or more, and the rolling in the pass 1 pass before the final pass Finishing hot rolling at a temperature in the range of 220 to 370 ° C. with a speed of 100 m / min or more, a rolling speed in the final pass of 150 m / min or more, and a reduction rate in the final pass of 20 to 70%. And obtained hot pressure The plate is heated to a temperature in the range of 220 to 500 ° C. at an average temperature increase rate of 10 to 50 ° C./hour, held for 0.5 to 24 hours, and cooled at an average cooling rate of 10 to 50 ° C./hour. It is characterized by performing intermediate annealing by batch annealing and further performing final cold rolling at a rolling rate of 40% or more.
[0010]
Furthermore, the manufacturing method of the aluminum alloy hard plate for can lids of invention of Claim 3 is the manufacturing method of the aluminum alloy hard plate for can lids of Claim 1 or Claim 2, WHEREIN: Between the said hot rolling and intermediate annealing. In the meantime, primary cold rolling with a rolling rate of 5 to 40% is performed.
[0011]
And the manufacturing method of the aluminum alloy hard plate for can lids of invention of Claim 4 is the manufacturing method of the aluminum alloy hard plate for can lids of Claim 1 or Claim 2, After the said last cold rolling, Furthermore, the final annealing is performed by heating and holding at a temperature in the range of 100 to 240 ° C. for 10 hours or less.
[0012]
Furthermore, the manufacturing method of the aluminum alloy hard plate for can lids of invention of Claim 5 is the manufacturing method of the aluminum alloy hard plate for can lids of Claim 1 or Claim 2, Said each element as an alloy of a raw material In addition, an alloy containing at least one selected from Cu 0.01 to 0.50% and Cr 0.05 to 0.50% is used.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
First, the reasons for limiting the components of the aluminum alloy used in the present invention will be described.
[0014]
Mg:
The addition of Mg is effective in improving the strength due to its own solid solution, and since the interaction with dislocations is large, an improvement in strength due to work hardening can be expected. Therefore, in order to obtain the strength required as a can lid material, Mg Is an indispensable element. However, if the Mg content is less than 0.8%, sufficient strength as a can lid material cannot be obtained, while if it exceeds 3.0%, the production cost increases. Therefore, the Mg content is set in the range of 0.8 to 3.0%.
[0015]
Mn:
The addition of Mn has a great effect on the generation and strength improvement of Al-Mn- (Si) and Al-Fe-Mn- (Si) -based crystals that improve the tearability of the score part and improve the can openability. Bring. When the amount of Mn is less than 0.01%, these effects are small. On the other hand, when the amount exceeds 1.2%, Al—Mn— (Si) and Al—Fe—Mn— (Si) based crystals are coarsened. It causes a decrease in workability. Therefore, the amount of Mn is set within a range of 0.01 to 1.2%. Further, by using Mn-added alloy system as described above, it is possible to use scrap materials of Mn-containing alloys such as 5182 alloy can lid materials and 3004 alloy can body materials, and improve recyclability. it can.
[0016]
Fe:
The addition of Fe has an effect on the formation of an Al-Fe-Mn- (Si) -based crystallized product that improves the tearability of the score portion and improves the openability. Fe has a great effect on crystal grain refinement that improves the moldability required as a can lid material. The larger the amount of Fe added, the finer the crystal grain. However, if the amount of Fe is less than 0.10%, the effect does not appear. On the other hand, if it exceeds 0.50%, the crystallized material becomes coarse and the formability is lowered. Therefore, the amount of Fe is set in the range of 0.10 to 0.50%.
[0017]
Si:
The Mg ₂ Si crystallized product formed of Si also has an effect of improving tearability of the score portion and improving can openability. However, when the amount of Si is less than 0.05%, the effect does not appear. On the other hand, when it exceeds 0.40%, a large crystallized product is generated and the number of crystallized products generated is excessively increased, causing a decrease in moldability. Therefore, the Si amount is set in the range of 0.05 to 0.40%. Si is an element contained as an unavoidable impurity in a normal aluminum alloy, and even in an alloy used in the method of the present invention, it is allowed to contain less than 0.05% of Si as an impurity.
[0018]
{Fe amount (%) + Mn amount (%)} / Si amount (%) ≦ 20:
When the amount of Fe and the amount of Si satisfy this condition, the formation of Al-Fe-Mn-Si crystallized product can be promoted, and the crystallized product size can be reduced. If the crystallized size is reduced, the density of randomly oriented grains growing from the periphery of the crystallized substance is reduced, and therefore cubic oriented grains that contribute to the formation of 0 ° -90 ° ears are preferentially grown, and as a result As a result, the ear rate of the product plate can be kept low. Therefore, the value of {Fe amount (%) + Mn amount (%)} / Si amount (%) is defined as 20 or less.
[0019]
Furthermore, in the alloy used in the present invention, one or both of Cu and Cr may be added in order to further improve the strength. The reasons for these limitations are as follows.
[0020]
Cu:
The addition of Cu is effective for improving the strength. Therefore, when further improving the strength of the can lid material, Cu may be added. However, if Cu is added excessively, the corrosion resistance, which is an important characteristic as a can lid material, may be reduced, and if Cu is added, work hardening characteristics increase, leading to a decrease in moldability. There is. Therefore, the amount of Cu added is within the range of 0.01 to 0.50%.
[0021]
Cr:
Addition of Cr is also effective for improving the strength, and Cr may be added to further improve the strength. However, when the Cr content is less than 0.05%, the effect does not appear. On the other hand, when the Cr content exceeds 0.50%, a giant crystallized product is generated and the number of crystallized products generated is too large, resulting in a decrease in formability. . Therefore, the Cr addition amount is set in the range of 0.05 to 0.50%.
[0022]
In addition to the above elements, Al and inevitable impurities may be used. However, in a normal aluminum alloy, a small amount of Ti may be added to refine the ingot structure. About the alloy used in the method of the present invention However, it is permissible to add a small amount of Ti. However, if the amount of Ti added is large, the ingot structure is unlikely to become feathery crystals, and granular crystals are likely to be generated. In the case of granular crystals, there is a risk that the crystallized material that crystallizes at the grain boundary will be coarser than in the case of feathery crystals, and if the amount of Ti increases, a large crystallized product is generated and molded. There is a risk of reducing the performance. Therefore, the Ti content is desirably 0.03% or less.
[0023]
Next, the manufacturing process in the method of the present invention will be described.
[0024]
First, an aluminum alloy having the above-described composition is melted according to a conventional method, and cast according to a conventional method such as a DC casting method. The ingot is subjected to a homogenization treatment and then heated for hot rolling, or is also heated for hot rolling in combination with the homogenization treatment. These heating conditions are not particularly limited and may follow a conventional method, but the heating immediately before the hot rolling is of course performed at a temperature that is higher than the hot rolling start temperature and does not cause melting. .
[0025]
The hot rolling conditions have a great influence on the performance of the final plate, particularly the ear rate, and therefore must be strictly regulated according to the following conditions (1) to (4).
(1) Hot rolling start temperature: 400-580 ° C
(2) Rolling speed before each pass:
Rolling speed in the pass two passes before the final pass; 50 m / min or more Rolling speed in the pass one pass before the final pass; 100 m / min or more Rolling speed in the final pass; 150 m / min or more (3) Final Pass reduction: 20-70%
(4) Hot rolling finish temperature: 220-370 ° C
[0026]
The reason why the hot rolling conditions (1) to (4) are determined is as follows.
[0027]
If the starting temperature of hot rolling is less than 400 ° C, recovery and recrystallization during hot rolling are suppressed, and there is a risk of edge cracking of the plate, while hot rolling at a high temperature exceeding 580 ° C. If started, the surface quality of the plate will be degraded. Therefore, the hot rolling start temperature needs to be a temperature within the range of 400 to 580 ° C.
[0028]
The rolling speed of the final pass and several previous passes in each pass of hot rolling affects the accumulated strain due to hot rolling, and in the subsequent intermediate annealing, the final plate has a low speed through the development of 0 ° -90 ° ears. It has a great influence on the generation of cube-oriented grains (cube-oriented grains) that contribute to increasing the ear ratio. And the higher the rolling speed of the final pass and several previous passes, the greater the accumulated strain due to hot rolling, and the higher the density of cubic oriented grains produced in the subsequent intermediate annealing, resulting in the lower edge of the final plate. It becomes effective for rate. Rolling speed conditions at a rolling speed of 50 m / min or more before the second pass from the final pass, rolling speeds of 100 m / min or more before the first pass from the final pass, and rolling speeds of 150 m / min or more at the final pass. Is not satisfied, the accumulated strain during hot rolling is small, so in the subsequent intermediate annealing, cubic orientation grains that contribute to the formation of 0 ° -90 ° ears are not sufficiently formed, and as a result, after the intermediate annealing As a result, the balance with the 45 ° ears developed in the cold rolling of the steel sheet cannot be maintained, so that it becomes impossible to achieve the low ear rate of the final plate. Therefore, the rolling speeds of 2 passes before, 1 pass before and after the final pass of the hot rolling were determined as described above.
[0029]
In addition, if the rolling reduction of the final pass of hot rolling is less than 20%, it becomes difficult to accumulate sufficient strain, and in the subsequent intermediate annealing, the growth of cubic orientation grains that contribute to lowering the audibility of the final plate is promoted. Difficult to do. On the other hand, when the rolling reduction of the final pass exceeds 70%, the surface quality of the plate may be deteriorated. Therefore, the rolling reduction of the final pass is set in the range of 20 to 70%.
[0030]
Furthermore, when the end temperature of hot rolling is a low temperature of less than 220 ° C., the nucleation and growth of random orientation from the deformation zone of the material, the periphery of the crystallized material, and the like are stimulated. It becomes difficult to increase the density of the grains, and recovery and recrystallization in hot rolling are suppressed, so that edge cracking of the plate is likely to occur. On the other hand, if the hot rolling finish temperature exceeds 370 ° C., sufficient strain cannot be accumulated due to recovery and recrystallization during hot rolling, and as a result, it contributes to lowering the ear ratio of the final plate in the subsequent intermediate annealing. It becomes impossible to increase the density of cubic orientation grains that promote the development of 0 ° -90 ° ears. Therefore, the hot rolling end temperature needs to be in the range of 220 to 370 ° C.
[0031]
As described above, the hot-rolled sheet obtained by hot rolling according to the conditions (1) to (4) is subjected to intermediate annealing as it is, or 1 as defined in claim 3. After the next cold rolling, intermediate annealing is performed.
[0032]
This intermediate annealing is an indispensable process for recrystallizing the material to form a cubic grain structure. Even if continuous annealing is applied as defined in claim 1, it is also defined in claim 2. Thus, batch annealing may be applied.
[0033]
When applying the continuous annealing, it is heated to a temperature within the range of 320 to 550 ° C. to keep it for 10 minutes or less. Here, when the heating temperature of continuous annealing is less than 320 ° C., recrystallization does not proceed, and therefore a cubic orientation grain structure cannot be generated, and as a result, a low ear ratio cannot be achieved. On the other hand, if the heating temperature for continuous annealing exceeds 550 ° C., the recrystallized grains become coarse and the formability of the final plate is lowered. Moreover, if the heating and holding time of continuous annealing exceeds 10 minutes, productivity will be reduced.
[0034]
On the other hand, when batch annealing is applied, it is heated to a temperature in the range of 220 to 500 ° C. at an average temperature increase rate of 10 to 50 ° C./hour, held for 0.5 to 24 hours, and 10 to 50 ° C./hour. Cool at average cooling rate. In such intermediate annealing by batch annealing, when the heating temperature is less than 220 ° C., recrystallization does not proceed, so that a cubic grain structure cannot be generated, and as a result, a low ear ratio of the final plate is achieved. I can't. On the other hand, if the heating temperature for batch annealing exceeds 550 ° C., the recrystallized grains become coarse and the formability of the final plate is lowered. In addition, if the heating and holding time of batch annealing is less than 0.5 hours, it is difficult to recrystallize uniformly. On the other hand, if it exceeds 24 hours, the recrystallized grains may be coarsened, and the productivity will be reduced. . Furthermore, in batch annealing, from the viewpoint of productivity, the average heating rate and the average cooling rate are 10 to 50 ° C./hour.
[0035]
Prior to the intermediate annealing as described above, primary cold rolling may be performed as described above. This primary cold rolling has an effect of promoting the growth of cubic oriented grains generated in the subsequent intermediate annealing, and it is necessary to perform rolling within a range of a rolling rate of 5 to 40%. When the rolling ratio of the primary cold rolling is less than 5%, the above-mentioned effect cannot be obtained. On the other hand, when the rolling ratio exceeds 40%, the number of nucleation sites that decrease the 0 ° -90 ° ear is increased. As a result, the density of the cubic orientation grains cannot be increased in the subsequent intermediate annealing, and the ear ratio of the final plate is lowered.
[0036]
As described above, after the hot rolling, intermediate annealing is performed immediately, or after the first cold rolling is performed and then the intermediate annealing is performed, the final cold rolling is performed at a rolling rate of 40% or more. If the rolling rate of the final cold rolling is less than 40%, it is difficult to obtain high strength desired as a can lid material. In addition, in the final cold rolling of 40% or more in this way, by appropriately controlling the rolling reduction rate and rolling speed of each pass, the plate temperature can be reached to 100 ° C. or more by processing heat generation. The effect of self-annealing can be obtained in the state of being wound on a coil immediately after the end of cold rolling. And by this self-annealing, dislocations introduced during the final cold rolling can be eliminated, the strength can be made uniform in each direction, and the strength anisotropy can be reduced. In addition, although the upper limit of the rolling rate in final cold rolling is not prescribed | regulated in particular, from the relationship with ingot thickness or product thickness etc., it is usually 95% or less.
[0037]
The plate after the final cold rolling may be used as it is as a can lid material, but in order to further reduce the strength anisotropy, the final heating is performed for 10 hours or less at a temperature in the range of 100 to 240 ° C. It is desirable to perform annealing. This final annealing is effective for eliminating the dislocations introduced by the final cold rolling, making the strength in each direction uniform, and reducing the strength anisotropy. Therefore, even if the process up to the final cold rolling is performed under the conditions specified in the present invention and the strength anisotropy is still large to some extent, it is desirable to perform the final annealing. Here, when the final annealing temperature is lower than 100 ° C., the above-described effect cannot be obtained. On the other hand, when the final annealing temperature is higher than 240 ° C., the progress of recovery is too large and the strength is insufficient. Further, if the heating time of the final annealing exceeds 10 hours, the productivity is lowered. Accordingly, the final annealing needs to be performed at a temperature within the range of 100 to 240 ° C. for 10 hours or less.
[0038]
As described above, a can lid material that has low ear ratio, low strength anisotropy, and has the strength, formability, tearability (can openability), etc. necessary for a can lid material. And can be obtained stably.
[0039]
【Example】
Alloy No. 1 in Table 1 Various aluminum alloys shown in 1 to 6 were cast by a DC casting method according to a conventional method, and the obtained ingot was used as a can lid material according to the processes and conditions shown in production codes A to H in Table 2. That is, after performing the ingot heat treatment, hot rolling is performed under the conditions shown in Table 2, and the obtained hot-rolled sheet is subjected to intermediate annealing as it is (manufacturing codes A, B, D to H), or 1 After the next cold rolling, intermediate annealing is performed (manufacturing code C), and the final cold rolling is performed to obtain a sheet thickness of 0.26 mm, and some of them (manufacturing codes A to D, F, G) Performed the final annealing.
[0040]
Each of the can lid materials obtained as described above was subjected to a heat treatment at 250 ° C. for 24 seconds corresponding to the coating baking process, and then the ear rate and the strength anisotropy were examined. Shown in The ear rate was examined by conducting a cup drawing test under the conditions of a blank diameter of 62 mm and a drawing ratio of 1.9. Here, if the ear rate exceeded 6%, it was determined to be unacceptable. On the other hand, regarding the strength anisotropy, the proof stress in each direction of 0 °, 45 ° and 90 ° with respect to the rolling direction was examined, and the maximum value of the proof stress difference in each direction (maximum proof stress difference) was obtained. When this maximum proof stress difference exceeded 25 MPa, it was determined that the strength anisotropy was rejected.
[0041]
[Table 1]

[0042]
[Table 2]

[0043]
[Table 3]

[0044]
In Tables 1 to 3, the can lid materials according to production codes A to C produced according to the production process conditions of the present invention using alloys within the component composition range defined in the present invention have low ear ratio and strength. It was confirmed that anisotropy (maximum yield strength difference) was also small.
[0045]
On the other hand, production codes D to F are comparative examples in which the composition of the components used the alloy within the range of the present invention, but the production process conditions did not satisfy the range defined by the present invention. Specifically, production code D is an example in which the rolling speed in the final pass of hot rolling was slow, but in this case, the ear rate was high. Production code E is an example in which the hot rolling end temperature is too low, but in this case, the ear rate is high, and the final annealing is not performed, so that the strength anisotropy is also increased. . Further, production code F is an example in which the rolling reduction of the final pass of hot rolling is too small, but in this case, the ear rate is high.
[0046]
Further, production codes G and H are examples using a comparative alloy whose component composition is out of the range specified in the present invention. Among these, the production code G has a value of {Fe amount (%) + Mn amount (%)} / Si amount (%) of 23.3 which is too high. In this case, the ear rate was high. The production code H is alloy No. with an excessive amount of Mg. However, in this case, the ear rate was increased, and the strength anisotropy was increased because the final annealing was not performed.
[0047]
【The invention's effect】
According to the method for producing an aluminum alloy hard plate for a can lid according to the present invention, the ear rate is stable and low, the strength anisotropy is small, and the strength, formability, tearability (can openability), etc. The can lid material excellent in general performance required for the lid material can be surely obtained. Therefore, if the plate obtained by the method of the present invention is used for the can lid, it can be wound with the can body material. At the time, there is little possibility that a winding failure will occur, and since there is little anisotropy in strength, it is possible to exert excellent effects such as being less likely to break from the score portion due to the impact of dropping the can. In addition, since the aluminum alloy hard plate for can lids according to the method of the present invention uses an alloy of a system containing Mn, use scraps such as 5182 alloy can lid materials and 3004 alloy can body materials that consume a large amount. Therefore, it is excellent in recyclability.

Claims (5)

Mg 0.8-3.0% (% by weight, the same shall apply hereinafter), Mn 0.01-1.2%, Fe 0.10-0.50%, Si 0.05-0.40%, and {Fe amount (%) + Mn amount (%)} / Si amount (%) is 20 or less, and the remainder is made of an alloy composed of Al and inevitable impurities, and when the ingot is hot-rolled, hot rolling start temperature Is within the range of 400 to 580 ° C., the rolling speed in the pass 2 passes before the final pass is 50 m / min or more, the rolling speed in the pass 1 pass before the final pass is 100 m / min or more, and the rolling speed in the final pass 150 m / min or more, and the rolling reduction in the final pass is in the range of 20 to 70%, the hot rolling is terminated at a temperature in the range of 220 to 370 ° C., and the obtained hot rolled sheet, Temperature in the range of 320-550 ° C Production of aluminum alloy hard plate for can lid, characterized by subjecting to intermediate annealing by continuous annealing without heating or holding for 10 minutes or less, and further performing final cold rolling at a rolling rate of 40% or more Method. Mg 0.8-3.0%, Mn 0.01-1.2%, Fe 0.10-0.50%, Si 0.05-0.40%, and {Fe amount (%) + Mn amount (% )} / Si amount (%) is 20 or less, and the remainder is made of an alloy composed of Al and unavoidable impurities. When hot rolling the ingot, the hot rolling start temperature is in the range of 400 to 580 ° C. And the rolling speed in the pass two passes before the final pass is 50 m / min or more, the rolling speed in the pass one pass before the final pass is 100 m / min or more, and the rolling speed in the final pass is 150 m / min or more, Furthermore, the rolling reduction in the final pass is set within the range of 20 to 70%, the hot rolling is terminated at a temperature within the range of 220 to 370 ° C., and the average rate of temperature increase is 10 to 50 with respect to the obtained hot rolled sheet. ℃ / hour 220 ～ 500 ℃ Heat to ambient temperature, hold for 0.5 to 24 hours, perform intermediate annealing by batch annealing to cool at an average cooling rate of 10 to 50 ° C./hour, and further carry out final cold rolling at a rolling rate of 40% or more The manufacturing method of the aluminum alloy hard plate for can lids characterized by performing. In the manufacturing method of the aluminum alloy hard plate for can lids of Claim 1 or Claim 2,
A method for producing an aluminum alloy hard plate for a can lid, wherein primary cold rolling at a rolling rate of 5 to 40% is performed between the hot rolling and the intermediate annealing. In the manufacturing method of the aluminum alloy hard plate for can lids of Claim 1 or Claim 2,
A method for producing an aluminum alloy hard plate for a can lid, wherein after the final cold rolling, final annealing is further performed by heating and holding at a temperature within a range of 100 to 240 ° C for 10 hours or less. In the manufacturing method of the aluminum alloy hard plate for can lids of Claim 1 or Claim 2,
In addition to the above component elements, an alloy containing one or more selected from Cu 0.01 to 0.50% and Cr 0.05 to 0.50% is used as a material alloy. The manufacturing method of the aluminum alloy hard board for can lids.