JPH09256129A - Production of high strength heat treated type aluminum alloy sheet for drawing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an aluminum alloy sheet having a high strength as an Al alloy sheet for drawing used for a DI can body, a DRD can body, a can top or the like, furthermore excellent in can formability such as drawability and ironing properties and moreover small in a secular change in the material characteristics. SOLUTION: An Al alloy composed of, by weight 3 to 6% Zn, 0.5 to 3% Mg, >0.5 to 1.5% Mn, and the balance substantial Al is finished into a prescribed sheet thickness, which is thereafter subjected to short time solution treatment at 450 to 550 deg.C for <=5min, is furthermore subjected to artificial aging treatment at 80 to 150 deg.C for 1 to 24hr and is then subjected to final cold rolling. As for an Al alloy contg. 1 to 2.5% Cu in addition to the above each component, it is finished into a prescribed sheet thickness, which is thereafter subjected to short time solution treatment at 450 to 540 deg.C for <=5min and is subjected to artificial aging treatment and final cold rolling similar to the above.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a heat-treatable aluminum alloy plate for drawing which requires high strength, and more particularly to a can body, can lid material or food can (DRD can) of an aluminum two-piece DI can. ) And the like, and mainly relates to a method for producing an aluminum alloy sheet for drawing used as a container material.

[0002]

2. Description of the Related Art As an aluminum container that is used after being drawn, a two-piece DI can that is formed by DI processing (drawing-ironing) or DRD processing (drawing-redrawing) is used. There are DRD cans (food cans) that are formed by molding and various deep-drawing cans. The most typical method for producing DI cans among these aluminum cans is to perform deep drawing and ironing on the can body material.
After I processing is performed to obtain the can body shape, trimming is performed to a predetermined size, then paint baking is applied, and then necking processing (mouth drawing) and flange processing (mouth widening processing) are applied to the can body edge. ) Is performed, and the can lid (can end) that has been separately molded is combined and subjected to seaming (winding). Since various types of processing are applied to the production of DI cans, etc., it is a balance between various workability such as deep drawability, ironing property, mouth drawability, mouth spreadability, and overhangability, and strength. From that, the material is selected and examined.

Among the various aluminum cans as described above, H19 or H39 of JIS 3004 alloy or AA3104 alloy is often used as a can body for DI cans, and the can lid of DI cans is JIS. H of 5052 alloy, JIS 5082 alloy, JIS 5182 alloy
18 materials or H38 materials are often used, and DRD
JIS 5052 alloy H1 for cans and other deep drawn cans
Eight materials, H38 material, H38 material of AA5042 alloy, etc. are often used.

[0004]

For aluminum cans represented by aluminum two-piece DI cans, it is strongly desired to make them thinner than before in order to reduce the material cost. Therefore, as a material for these aluminum cans, a material that has a sufficiently high strength even when it is made thin and is capable of ensuring excellent formability such as drawability is desired. However, in the conventional aluminum alloy plate for aluminum cans as described above, for example, in the case of an alloy plate for a can body, at the time of paint baking at about 200 ° C. for 20 minutes after the can is made, and in the case of an alloy plate for a can lid, Since the softening occurs during the previous baking process of 270 ° C for about 20 seconds, the strength finally obtained is at most about 300 N / mm ^2, so the strength is insufficient for thinning. Will end up.
Further, based on the conventional alloy system as described above, for example, C
It is possible to improve the strength by adding a strengthening element such as u or increasing the cold working rate of the material, but in that case, the formability is remarkably reduced, and as a can material Would be inappropriate.

Among various aluminum alloys, 2000 series (Al--Cu--Mg series) or 7000 series.
The heat treatment type alloys of the Al-Zn-Mg-based type are often used as structural materials that require high strength because they can obtain high strength exceeding 400 N / mm ^{2 in} proof stress. In this case, it is usually used in the state of solution treatment as it is, or in the state of being subjected to artificial aging treatment, and even if it is subjected to molding processing, it is only a very slight processing. When these heat-treatable alloys are used for applications requiring strong forming, they are also formed in a soft material state and then subjected to solution treatment or artificial aging treatment to secure the strength. However, such a process is unsuitable as a material for cans. In any case, although these conventional heat-treatable alloys have sufficiently high strength, they are inferior in formability, especially drawability, ironing property, and overhanging property after the solution treatment, and therefore are applied to can materials. That was not considered.

Further, in the case of a material for a can body of a DI can, not only high strength and excellent DI formability (drawing workability, ironing workability) are required, but also a DI can body is formed and a paint baking treatment is performed. Formability in necking, flanging and seaming after application is also required. Since the thickness of the flange has been decreasing with the thinning of the can body in recent years, it is easy for the flange to break during flanging and seaming, which improves flanging and seaming. There is also a strong demand for a smaller neck diameter in order to reduce the weight of the can lid, and thus an increase in the amount of necking, and therefor a further improvement in the formability of the flange portion is required. Further, in the case of a can lid material, in addition to deep drawing property, further improvement in overhanging property and opening property is desired.

By the way, the present invention has already been disclosed in Japanese Patent Application No. 7-15.
In 3899, "a high-strength heat-treatable aluminum alloy plate for drawing and a manufacturing method thereof" is proposed.
This proposal is basically a heat treatment type DI can alloy based on a 7000 series alloy and a heat treatment method thereof. Specifically, Zn3 to 6 wt%, Mg0.5
˜3 wt%, Mn exceeding 0.5 wt% and 1.5 wt% or less, and the balance D consisting of Al and unavoidable impurities
In addition to the alloys for I cans or the above alloy elements, Cu0.
At the same time as proposing alloys for DI cans to which 1 to 2.5 wt% is added, at the same time after finishing these alloys to a predetermined plate thickness, within the range of 450 to 550 ° C. or 450 to 5 ° C.
The solution heat treatment is performed at a temperature within the range of 40 ° C., and further 30
It proposes a method of performing cold rolling at a rolling ratio of more than 75% and 75% or less.

According to the above-mentioned proposal, it is possible to exhibit high strength as a heat treatment type alloy, to secure good formability such as drawability, and to satisfy the above-mentioned various requirements. However, as a result of further study for practical use, the alloy proposed above is unique to heat-treatable alloys during the period such as storage after the plate material is manufactured by the material manufacturer and before the can is manufactured by the manufacturer. There is a problem that the strength of the material, especially the proof stress, rises with the lapse of time, so that if a long time elapses from plate manufacturing to can manufacturing, the formability such as ironing property during can manufacturing decreases, and other plate manufacturing. It was found that there is a problem in that strength and moldability during can making vary depending on the period until later can making.

The present invention has been made in view of the above circumstances, and at the same time, it is possible to satisfy the above-mentioned various requirements, and at the same time, there is little change with time after the plate is manufactured, and after a long time has passed since the plate was manufactured. It is an object of the present invention to provide a method for producing an aluminum alloy sheet for drawing, which is less likely to cause deterioration in forming processability such as ironing property and variation in material properties even when making a can.

[0010]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the inventors of the present invention have conducted extensive experiments and researches, and as a result, by appropriately determining the manufacturing process and manufacturing conditions for the alloy having the above-mentioned composition of ingredients. It has been found that an aluminum alloy sheet that not only exhibits high strength as a heat-treatment type alloy but also has good formability such as drawability, and that has little change over time after the sheet is manufactured. Came to make.

Specifically, the method for producing a high-strength heat-treatable aluminum alloy plate for drawing according to the first aspect of the invention comprises:
3-6%, Mg 0.5-3%, Mn 0.5% and over 1.
After the alloy containing 5% or less and the balance of Al and unavoidable impurities is finished to a predetermined plate thickness, 450 to 55
Solution heat treatment for 5 minutes or less at a temperature in the range of 0 ° C, artificial aging treatment for 1 to 24 hours at a temperature in the range of 80 to 150 ° C, and cold rolling at a rolling ratio of 70% or less. It is characterized by being rolled.

The method for producing a high-strength heat-treatable aluminum alloy plate for drawing according to the second aspect of the invention is Zn3-6.
%, Mg 0.5 to 3%, Cu 0.1 to 2.5%, Mn
After finishing an alloy containing 0.5% or more and 1.5% or less with the balance being Al and unavoidable impurities to a predetermined plate thickness, a solution for 5 minutes or less at a temperature in the range of 450 to 540 ° C. Chemical aging treatment, then artificial aging treatment for 1 to 24 hours at a temperature in the range of 80 to 150 ° C., and further cold rolling at a rolling ratio of 70% or less.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, in terms of composition of components, basically, as a heat-treatable alloy, strength is improved by precipitation hardening by Zn and Mg, and M
The addition of n stabilizes the structure and improves the ironing workability, and if necessary, Cu is added to strengthen the solid solution to enhance the strength. In terms of the manufacturing process, the solution treatment time is shortened. In order to ensure sufficient formability as a material for drawing work as time, and also to perform artificial aging treatment under appropriate conditions after solution treatment, it is intended to suppress the change over time after plate production.

Therefore, first, the reasons for limiting the component composition in the present invention will be explained.

Zn: Zn forms MgZn ₂ together with Mg and is effective in improving the strength by precipitation hardening. If the Zn content is less than 3%, the effect of improving the strength cannot be sufficiently obtained, while if it exceeds 6%, the rolling property and the can formability are deteriorated, and further the corrosion resistance is deteriorated. Therefore Zn
The amount was within the range of 3 to 6%.

Mg: Mg forms MgZn ₂ together with Zn and is effective in improving strength by precipitation hardening. Also M
g alone is effective for improving strength by solid solution strengthening.
If the amount of Mg is less than 0.5%, the effect of improving the strength cannot be sufficiently obtained, while if it exceeds 3%, the rolling property decreases and
Reduces can formability. Therefore, the amount of Mg is 0.5 to 3
%.

Mn: Mn is an element effective for refining and stabilizing crystal grains, and improves the ironing workability by the solid lubrication effect of the Mn-based intermetallic compound. If the amount of Mn is 0.5% or less, these effects cannot be sufficiently obtained, while if it exceeds 1.5%, primary crystal giant intermetallic compounds of MnAl ₆ are generated, and formability, especially flange formability is remarkably increased. It was damaged, and MgZn was added to the Mn-based intermetallic compound.
₂ Precipitates are unevenly and coarsely deposited, making it impossible to improve strength. Therefore, the Mn content exceeds 0.5% and 1.
It was set within the range of 5% or less.

Cu: Cu is an element effective in improving the strength by solid solution strengthening, and therefore it was decided to add it positively in the alloy of the invention of claim 2. If the Cu content is less than 0.1%, the effect of improving the strength cannot be sufficiently obtained, while if it exceeds 2.5%, the formability and corrosion resistance deteriorate. Therefore, claim 2
In the present invention, the amount of Cu is within the range of 0.1 to 2.5%. Of course, in the alloy according to the first aspect of the present invention, Cu may be contained as an impurity in an amount of less than 0.1%.

In addition to the above elements, Al and unavoidable impurities may be basically used. Common impurities include Fe, Si, Cr, Zr, etc., but Fe is 0.7
%, Si is less than 0.5%, Cr is less than 0.3%, Z
If r is less than 0.3%, the effect of the present invention is not impaired. Further, in general aluminum alloys, a small amount of Ti may be added alone or in combination with B in order to refine the ingot structure, and Ti and B may be contained as impurities. Ti is less than 0.2%,
If B is less than 0.05%, the effect of the present invention is not particularly impaired.

Next, the manufacturing process in the present invention will be described.

The step of finishing the alloy having the above-mentioned composition of components to a predetermined intermediate plate thickness (process before solution treatment) is not particularly limited, but is usually cast by the DC casting method (semi-continuous casting method). After that, homogenization treatment is performed, hot rolling is further performed, and cold rolling is performed as necessary to obtain a predetermined intermediate plate thickness. Alternatively, a continuous casting method may be applied, and if necessary, homogenization treatment and cold rolling may be performed to obtain a predetermined intermediate plate thickness.

Here, DC casting may be performed according to a conventional method. Further, homogenization treatment is 400 to 500 ° C. according to a conventional method.
In the above, heating may be performed for about 1 to 24 hours. If the heating time of the homogenization treatment is less than 1 hour and the heating temperature is less than 400 ° C., the homogenization effect cannot be obtained.
If the time is exceeded, the homogenizing effect is saturated and the economic efficiency is impaired, and if the heating temperature exceeds 500 ° C., local dissolution due to eutectic melting may occur.

Immediately after the homogenization treatment or after preheating before hot rolling, hot rolling is performed. In this hot rolling, the starting temperature is within the range of 400 to 500 ° C. and the ending temperature is within the range. The temperature is preferably in the range of 200 to 350 ° C. If the hot rolling start temperature is lower than 400 ° C, the deformation resistance is large and the rolling property is deteriorated. On the other hand, if the hot rolling start temperature is higher than 500 ° C, hot rolling cracks may occur. Note that this hot rolling is preferably started at a homogenization treatment temperature or higher, and by doing so, formation of coarse precipitates after the homogenization treatment can be suppressed.
Further, if the hot rolling finish temperature is lower than 200 ° C., rolling is difficult, whereas if the hot rolling finish temperature is higher than 350 ° C., uneven coarse precipitation of intermetallic compounds is promoted after the hot rolling, and then Solution treatment property of and deteriorates drawability, bulging property, and mouth widening property.

On the other hand, when the continuous casting method is applied, a method of directly injecting molten metal between rolls to solidify (thin plate continuous casting method) or a method of injecting molten metal between belts and blocks to solidify May be applied, and in any case, hot rolling may be performed as necessary. When the continuous casting method is applied, the cast plate thickness is preferably within the range of 1 to 10 mm. If the thickness of the cast plate is less than 1 mm, it is difficult to perform casting. On the other hand, if it exceeds 10 mm, the load of cold rolling up to the subsequent product sheet thickness increases, and mass productivity decreases.

Cold rolling performed after hot rolling or continuous casting to obtain an intermediate plate thickness as necessary may be performed according to a conventional method, and the rolling ratio is not particularly limited.

After finishing the intermediate plate thickness as described above, a solution treatment is applied. This solution treatment is 450-
It is necessary to perform heating at a temperature in the range of 550 ° C. or a temperature in the range of 450 to 540 ° C. for a short time of 5 minutes or less.
If the solution heat treatment temperature is lower than 450 ° C., the solution of the element contributing to the strength improvement becomes insufficient due to the aging precipitation, so that the strength cannot be sufficiently improved. Further, in the case of the alloy of claim 1 in which Cu is not positively added, eutectic melting may occur if the solution treatment temperature exceeds 550 ° C., while Cu is actively added. In the case of the alloy (1), the melting point is lowered by the addition of Cu, so that if the solution treatment temperature exceeds 540 ° C., eutectic melting may occur. Further, this solution heat treatment requires 5 hours.
It is important that the time is not more than a minute and the solution is incomplete. That is, in general, the minimum solution treatment time of the 7000 series heat-treated alloy is specified in JIS 4000 in relation to the plate thickness. However, the solution treatment is performed for a long time in accordance with JIS to completely complete the solution treatment. In this case, although high strength is obtained, not only the subsequent cold rolling property is deteriorated, but also the can formability such as drawability and bulging property is deteriorated.
Also, if solution treatment is performed for a long time, the surface oxide film becomes thick, which deteriorates formability, especially ironing property, so surface cleaning treatment such as alkali cleaning or acid cleaning is required after solution treatment. Therefore, the cost is increased. On the other hand, if the solution heat treatment time is set to 5 minutes or less and incomplete solution heat treatment is performed, strength can be increased to the extent necessary for thinning the can, and drawability, overhanging property, and ironing property can be improved. Sufficient can formability can be secured, and the surface cleaning treatment after the solution treatment is not necessary. Such short-time solution heat treatment can be easily performed by using a continuous annealing furnace. The cooling rate after solution treatment was 10 ° C.
/ Sec or more is sufficient. Therefore, for cooling after the solution treatment, not only water quenching but also forced air cooling can be applied.

After the solution treatment, an artificial aging treatment is carried out by keeping the temperature within the range of 80 to 150 ° C. for 1 to 24 hours. By performing such artificial aging treatment, fine precipitates are generated to homogenize the working strain and improve the material strength, and the strength imparted by the subsequent final cold rolling is stabilized. Not only the cold rolling property is improved, but also the change of the final plate with time is suppressed, so that the formability during the can making does not decrease even after a long time until the can making. It is possible to reduce variations in strength and moldability depending on the period. That is, when the final cold rolling is carried out as it is after the solution heat treatment, there is a change over time after the plate is manufactured, and the strength during the can making is increased and the formability is lowered, or the strength and the formability during the can making are reduced. However, by precipitating fine precipitates by performing artificial aging treatment after solution treatment, precipitation of fine precipitates during the standing period during plate production is reduced, and The change can be prevented. Here, if the temperature in the artificial aging treatment is less than 80 ° C. or the holding time is less than 1 hour, the above effect cannot be sufficiently obtained, while if the temperature exceeds 150 ° C. or the holding time exceeds 24 hours, the over-aging is performed. Will result in a decrease in strength. Therefore, the artificial aging treatment was defined as a temperature of 80 to 150 ° C. for 1 to 24 hours.

After the solution treatment, it is preferable that the artificial aging treatment is not performed immediately, but the artificial aging treatment is performed after leaving it to stand at room temperature for one day (24 hours) or more for aging at room temperature. Thus, if the room temperature aging is performed for 24 hours or more before the artificial treatment, the fine precipitates generated during the room temperature aging densify the precipitate distribution due to the subsequent artificial aging treatment, and as a result, in the subsequent cold rolling. The effect of homogenizing the introduced dislocation (working strain) can be exerted.

After performing the artificial aging treatment as described above, cold rolling is performed to obtain the final plate thickness. This final cold rolling needs to be performed at a rolling rate of 70% or less.
When the rolling ratio exceeds 70%, although high strength is obtained, the formability is remarkably lowered and the earring ratio in deep drawing becomes large. Although the lower limit of the rolling ratio in the final cold rolling is not particularly defined, it is preferably 30% or more in order to obtain a sufficiently high strength.

After finishing the final product thickness by cold rolling, final annealing may be carried out at a temperature in the range of 80 to 160 ° C. for 1 to 12 hours, if necessary. By performing such final annealing, the strain can be stabilized and the deep drawability can be further improved. If the temperature of the final annealing is less than 80 ° C. and the time is less than 1 hour, the above effect cannot be obtained. On the other hand, if the temperature of the final annealing exceeds 160 ° C., overaging causes the strength to decrease, and if the time of the final annealing exceeds 12 hours, the strength becomes too high and the formability,
In particular, drawing workability, ironing workability, and flange formability are deteriorated, and in this case, depending on the temperature, overaging is caused, resulting in a decrease in strength. Since the recent cold rolling mill is operated under high speed and high pressure, the rising temperature often exceeds 100 ° C. In this case, even if the positive heating is not particularly performed, the winding coil immediately after the cold rolling is cooled. The final annealing can be performed by self-annealing.

[0031]

EXAMPLES Alloy No. of Table 1 The alloys 1 and 2 were cast by the DC casting method according to the usual method, and
After homogenizing treatment at 60 ℃ for 12 hours, after grinding, 470 ℃
Then, hot rolling was started to obtain a hot rolled plate having a plate thickness of 3 mm. In addition, alloy No. The alloy No. 3 was continuously cast-rolled to a thickness of 5 mm, and then homogenized at 460 ° C. for 12 hours. On the other hand, alloy No. 1 in Table 1 No. 4 is a conventional material equivalent to JIS 3004 alloy.
After homogenizing treatment at ℃ × 5 hours, after face-cutting 2 according to the usual method
It was hot rolled to a thickness of mm.

With respect to the hot rolled plate (or continuous casting and rolling plate) thus obtained, the manufacturing condition codes A to K in Table 2 are given.
Under the conditions shown in 1), primary cold rolling → solution treatment → artificial aging treatment → secondary cold rolling → final annealing was performed. It should be noted that the artificial aging treatment or the final annealing was omitted in some of the manufacturing condition codes B, E, and GI, and the artificial aging treatment was not performed in the manufacturing condition K for the conventional material (alloy No. 4).

Regarding each plate obtained as described above,
The mechanical performance and the DI can properties were examined. Table 3 shows the results. In terms of mechanical performance, the tensile strength in two states, that is, the state immediately after plate production (immediately after artificial aging treatment) as described above and the state after heating at 200 ° C. for 20 minutes as coating baking treatment ( TS), yield strength (YS), and elongation (EL) were examined. On the other hand, as DI can properties, can property, flange formability, pressure resistance and appearance quality were examined and evaluated in comparison with the conventional material (alloy No. 4; manufacturing condition code K). , ◎ when excellent, and × when inferior. Here, the can-making property was evaluated by the rate of occurrence of breakage during DI processing when 4000 cans of DI can bodies were continuously molded, and regarding the flange processability, the DI can body was subjected to necking processing after DI processing. rear,
Push in the conical punch and evaluate the expansion ratio when the flange part breaks, compressive strength is evaluated by the pressure when buckling occurs by applying internal pressure to the DI can, and the appearance quality is evaluated by goring and The presence or absence of flow lines and the degree of gloss were evaluated.

Further, alloy No. 1 in Table 1 was used. For the alloy of No. 1 as the time-dependent change of the material properties of each plate obtained by the processes of the production condition codes A to D in Table 2, the first day and the third day immediately after the plate production (immediately after the final annealing). The proof stress values on the 7th day, the 1st month and the 6th month were examined. The results are shown in Table 4. In Table 4, the "proof strength increase amount" represents the difference between the yield strength after 6 months and the yield strength on the first day. Also, as an evaluation, when the amount of increase in proof stress is within 10 N / mm ² , a mark of ○ is given,
When it exceeded 10 N / mm ² , an X mark was added.

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

[Table 3]

[0038]

[Table 4]

As shown in Table 3, for alloys (alloy Nos. 1 to 3) within the composition range defined by the present invention, a plate was manufactured under the conditions within the process range defined by the present invention. (Manufacturing condition code A, G, J) has achieved higher strength than the conventional material (alloy No. 4, manufacturing condition code K; 3004 alloy), and the DI can characteristics are equal or higher. Was confirmed.

On the other hand, the manufacturing condition code C is a comparative example in which the temperature of the artificial aging treatment is too high, and the manufacturing condition code E is a comparative example in which the artificial aging treatment time is too long. Also, the flange formability was poor. Further, the manufacturing condition code F is a comparative example in which the rolling ratio of the final cold rolling was too high, but in this case, the strength was too high and the can manufacturing property was poor, and the earring ratio after DI processing was high. The manufacturing condition code H is a comparative example in which the solution treatment temperature is too high.
In this case, the drawability was lowered due to the occurrence of eutectic melting, and the appearance quality was poor due to the occurrence of flow lines on the surface of the DI can. Manufacturing condition code I is a comparative example in which the solution treatment time was too long, but in this case, the can manufacturing property was deteriorated and the appearance defect was caused by the generation of flow lines due to the oxide film.

Table 4 shows changes with time in material characteristics.
As shown in FIG. 6, in the case of manufacturing condition code A manufactured under the process conditions specified in the present invention for the alloys within the compositional range specified in the present invention, the proof stress value increases only 7 N / mm ² even after 6 months have elapsed. It can be seen that the material has stable material properties. On the other hand, the manufacturing condition code B is a comparative example in which the artificial aging treatment was not performed after the solution treatment, and the manufacturing condition code D is a comparative example in which the temperature of the artificial aging treatment after the solution treatment was too low. It has been found that the yield strength increases significantly after one month to six months, and ironing property also decreases.

[0042]

As is clear from the above examples, according to the present invention, as an aluminum alloy plate for drawing used in various cans and the like, it has high strength and excellent formability, It has become possible to obtain an aluminum alloy plate which has particularly excellent drawability and ironing property, has little change over time, and has stable material properties for a long period of time. That is, a conventional Al-Mn-Mg-Cu alloy or Al-Mg
In the -Mn alloy, the drawability and ironing property are said to be lowered if the strength is increased, but in the case of the present invention, the composition of the components is strictly defined, and further, as a heat treatment type alloy, appropriate solution treatment conditions are applied. By optimizing the solid solution precipitation state of alloying elements, it is possible to secure good formability while increasing strength, and by applying an appropriate artificial aging treatment after solution treatment, heat treatment type It has become possible to suppress the time-dependent change peculiar to alloys. Therefore, when the aluminum alloy sheet according to the present invention is used, it is possible to reduce the thickness and increase the strength, especially as a material for cans, and the material characteristics during can making may vary depending on the elapsed time from plate production to can making. In particular, even if a long period of time elapses from plate production to can making, it is possible to prevent deterioration of moldability during can making and to stably make can. Further, the aluminum alloy sheet according to the method of the present invention can be applied not only to the DI can body and the DRD can body but also to the can lid. Therefore, since the can can be unialloyed, the recyclability can be improved.

Claims (2)

[Claims] 1. Zn 3 to 6% (weight%, the same applies hereinafter), M
An alloy containing g of 0.5 to 3% and Mn of more than 0.5% and 1.5% or less and the balance of Al and unavoidable impurities is finished to a predetermined plate thickness, and then within a range of 450 to 550 ° C. Solution treatment for 5 minutes or less at temperature, then 80-1
Manufacture of a high-strength heat-treatable aluminum alloy sheet for drawing, characterized by performing artificial aging treatment for 1 to 24 hours at a temperature in the range of 50 ° C. and further cold rolling at a rolling rate of 70% or less. Method. 2. Zn 3-6%, Mg 0.5-3%, Cu
An alloy containing 0.1 to 2.5%, Mn more than 0.5% and 1.5% or less, and the balance of Al and inevitable impurities is finished to a predetermined plate thickness, and then in the range of 450 to 540 ° C. Solution treatment for 5 minutes or less at the internal temperature, then 80 ~
Manufacture of a high-strength heat-treatable aluminum alloy sheet for drawing, characterized by performing artificial aging treatment for 1 to 24 hours at a temperature in the range of 150 ° C., and further performing cold rolling at a rolling rate of 70% or less. Method.