JP6532149B2 - Aluminum alloy sheet for can body and method of manufacturing the same - Google Patents

Description

  The present invention relates to an aluminum alloy sheet for can bodies and a method of manufacturing the same.

Generally, the can body includes a can having a can lid wound and tightened at its open end and a bottle can and the like having a cap screwed on the open end, and the contents such as a beverage are filled and sealed and distributed in the market. It is done. Such a can body is conventionally manufactured by DI (Drawing and Ironing) forming in which drawing and ironing are performed on a plate made of an aluminum alloy such as JIS 3004 (AA 3004) or JIS 3104 (AA 3104).
With the reduction in thickness and weight of the beverage can body, forming problems such as wrinkles in cup forming and DI forming and body breakage in DI forming are likely to occur. Therefore, in order to reduce the occurrence of forming defects, high formability is required of the aluminum alloy sheet for can bodies.

On the other hand, in order to reduce the weight of cans, it is necessary to reduce the thickness of the aluminum alloy sheet for can bodies, and in order to ensure the strength required for cans even if the thickness is thin, the material strength Need to improve.
However, in the case of an aluminum alloy, in general, the formability tends to decrease as the material strength is improved. Therefore, it is considered effective to improve the strength of the can by utilizing the bake-hard effect in the subsequent baking of the paint while maintaining low strength at the stage of cup forming and DI forming.

However, in order to obtain high bake hardness in an aluminum alloy, it is necessary to increase the addition amount of alloy components such as Si, Cu and Mg. Alternatively, it is necessary to raise the solution treatment temperature in the manufacturing process.
These methods are not preferable from the viewpoint of resource saving, and increase the manufacturing cost, and also increase defects such as casting cracks and surface defects of the rolled sheet, so there is a problem that they are not preferable methods. .

  In addition, in this type of beverage can, as an aluminum alloy sheet for can and barrel that can be manufactured at low cost without impairing ironing processability, Mg 0.8 to 1.4 wt%, Mn 0 as described in Patent Document 1 below. 7 to 1.3 wt%, Fe 0.2 to 0.5 wt%, Si 0.1 to 0.5 wt%, Cu 0.1 to 0.3 wt%, Ti 0.005 to 0.05 wt%, the balance being Al There is also proposed an aluminum alloy sheet for cans and cylinders, which is an aluminum alloy sheet consisting of unavoidable impurities and having a tensile strength and an elongation within a specific range.

JP 2001-262261 A

By the way, in this kind of beverage can, further reduction in thickness and weight is desired, and in order to achieve the reduction in thickness and weight, it is necessary to secure the pressure strength of the bottom of the can in the beverage can.
However, in order to obtain a can body which is light in weight and has excellent formability and excellent strength after baking hard while securing excellent compressive strength, as a result of advancing research on materials and manufacturing conditions in detail, the present invention I reached.

  The present invention has been made in view of the above-mentioned circumstances, and in addition to the contents of Si, Fe, Cu, Mn and Mg, by controlling the tensile strength of the as-rolled material and the material characteristics after baking, at the time of DI forming It is an object of the present invention to provide an aluminum alloy sheet for can bodies capable of obtaining an aluminum alloy sheet for can bodies having a low occurrence of breakage of the body and high can body strength and a method of manufacturing the same.

In order to solve the above-mentioned subject, the present invention adopted the following composition.
The present invention is, by mass%, Si: 0.25 to 0.45%, Fe: 0.3 to 0.55%, Cu: 0.2 to 0.45%, Mn: 0.30 to 0.78 Aluminum alloy sheet for can bodies containing 1.0% to 1.5% of Mg and the balance of Al containing unavoidable impurities, wherein the as-rolled material tensile strength (ASTS) is 310 MPa or less, The present invention relates to an aluminum alloy sheet for can bodies characterized in that the yield strength after baking (ABYS) is 280 MPa or more, and the difference between the as-rolled material tensile strength (ASTS) and the strength after baking (ABYS) is 10 MPa or less.

  In the present invention, it is more preferable that the as-rolled material tensile strength (ASTS) is 300 MPa or less, and the post-baking proof stress (ABYS) is 285 MPa or more.

The method for producing an aluminum alloy sheet for can bodies of the present invention is, by mass%, Si: 0.25 to 0.45%, Fe: 0.3 to 0.55%, Cu: 0.2 to 0.45% , Mn: 0.30 to 0.78%, Mg: 1.0 to 1.5%, and the remainder is after homogenization and soaking of an aluminum alloy ingot having a composition consisting of Al containing unavoidable impurities Hot rolling and cold rolling, continuous annealing, and final cold rolling to produce a can body sheet material, wherein the continuous annealing is performed at a heating rate of 10 to 200 ° C./sec, holding temperature C., holding time 1 to 30 seconds, cooling rate 10 to 200 C./sec, the final cold rolling reduction ratio is 55 to 75%, and the can obtained after the final cold rolling As-rolled material tensile strength (ASTS) of aluminum alloy sheet for body is 310 Pa or less, characterized in that the yield strength after the baking (Abys) is more than 280 MPa, to produce an aluminum alloy sheet for a can body difference is less 10MPa yield strength after baking the material tensile strength while rolling (ASTS) (ABYS) I assume.

  According to the present invention, in addition to controlling the contents of Mn, Mg, Si, Fe, and Cu within a preferable range, the material tensile strength, the material proof stress, and the material characteristics after baking are controlled at the time of rolling. There is an effect that it is possible to provide an aluminum alloy sheet for a can body which can suppress the occurrence of a crack, suppress a crack generation rate to a low level, and increase the can body strength, and a method of manufacturing the same.

FIG. 1 is a schematic view for explaining steps in producing a can body by canting the aluminum alloy sheet for a can body according to the present invention by DI processing.

Hereinafter, a first embodiment of an aluminum alloy sheet for can bodies (hereinafter sometimes abbreviated as an aluminum alloy sheet for can bodies) having excellent flow resistance to pinholes according to the present invention will be described.
The aluminum alloy sheet for can bodies of the present embodiment is, by mass%, Si: 0.25 to 0.45%, Fe: 0.30 to 0.55%, Cu: 0.20 to 0.45%, Mn It is an aluminum alloy sheet for can bodies containing 0.30 to 0.78%, Mg: 1.0 to 1.5%, and the balance composed of Al containing unavoidable impurities.

Moreover, as for the aluminum alloy plate of this embodiment, it is preferable that plate | board thickness as a raw material before producing it is 0.220 mm or more and 0.265 mm or less.
In addition, the as-rolled material tensile strength (ASTS) is 310 MPa or less, the post-baking yield strength (ABYS) is 280 MPa or more, and the difference between the as-rolled base material tensile strength (ASTS) and the post-baking yield strength (ABYS) is 10 MPa or less Is preferred.

[Component composition]
Hereinafter, the component composition limited in the aluminum alloy plate for can bodies of this embodiment is demonstrated. The content of each element described below is mass% unless otherwise specified, and includes the upper limit and the lower limit unless otherwise specified. Thus, for example, the expression of 0.25 to 0.45% means 0.25% or more and 0.45% or less.

"Si" 0.25 to 0.45%
In the aluminum alloy sheet for can bodies of the present embodiment, Si forms an intermetallic compound together with Mg etc. simultaneously contained, improves strength by solution hardening, precipitation hardening and dispersion hardening action, and Al-Mn- It is contained in an Fe-based intermetallic compound and has an effect of preventing seizing to the die at the time of ironing.
If the content of Si is less than 0.25%, sufficient strength can not be obtained, and the bake hardness also decreases. In addition, desired lubricity can not be secured in DI molding. When the content of Si exceeds 0.45%, the strength becomes too high, and when the can body is produced as a can body, the torso is easily generated and the processability is deteriorated. In this range, the Si content is more preferably 0.28% or more.

"Fe" 0.30 to 0.55%
In the aluminum alloy sheet for can bodies of the present embodiment, Fe increases the amount of precipitation of the Al-Mn-Fe-based intermetallic compound, thereby making crystals finer and causing seizing to the die during ironing. It has the effect of preventing.
If the content of Fe is less than 0.30%, the amount of precipitation of the Al-Mn-Fe-based intermetallic compound becomes too small, which easily causes baking to an ironing die. When the content of Fe exceeds 0.55%, the amount of the Al-Mn-Fe based intermetallic compound becomes too large, and the workability decreases due to the decrease in toughness, and pinholes tend to occur. Accordingly, the content of Fe is preferably in the range of 0.30 to 0.55%.
In this range, the Fe content is more preferably in the range of 0.40 to 0.50%.

"Cu" 0.20 to 0.45%
In the aluminum alloy sheet for can bodies of the present embodiment, Cu has an effect of enhancing the strength by solution hardening, precipitation hardening and dispersion hardening.
If the Cu content is less than 0.20%, a sufficient strength improvement effect can not be obtained, and the bake hardness also decreases. If the content of Cu exceeds 0.45%, cracking during casting is likely to occur, side cracking during rolling is likely to occur, and productivity is lowered, and the strength is lowered and the strength is increased. When the can body is produced as a can body, it is likely that the body breaks. Even within this range, the amount of Cu is more preferably 0.25% or more.

"Mn" 0.30 to 0.78%
Mn forms an Al-Mn-Fe-based intermetallic compound in the aluminum alloy sheet for can bodies of the present embodiment, and exhibits a dispersion hardening action as a crystallized phase and a dispersed phase, and a die at the time of ironing and forming Has the effect of preventing the occurrence of burn-in.
If the content of Mn is less than 0.30%, the amount of the Al-Mn-Fe intermetallic compound becomes too small to obtain sufficient curing characteristics, and baking to an iron die tends to occur easily. . When the content of Mn exceeds 0.78%, the amount of Al-Mn-Fe-based intermetallic compound becomes too large, and the bake hard property is lowered. Even within this range, the Mn content is more preferably in the range of 0.40 to 0.75%.

"Mg" 1.0 to 1.5%
In the aluminum alloy sheet for can bodies of the present embodiment, Mg has a solid solution strengthening function, enhances work hardening during rolling, and exhibits dispersion hardening and precipitation hardening functions by coexistence with Si and Cu. Improve the strength.
When the content of Mg is less than 1.0%, sufficient strength can not be obtained, and the bake hardness also decreases. When the content of Mg exceeds 1.5%, side cracks are easily generated and the rollability is lowered, and the strength is too high and the workability is lowered, and the can body is cut when it is produced as a can body Is more likely to occur. Therefore, the content of Mg is preferably in the range of 1.0 to 1.5%. In addition, the range of 1.2 to 1.5% of Mg amount is more preferable also within this range.

[Method of manufacturing aluminum alloy sheet]
Hereinafter, an example of the manufacturing method of the aluminum alloy plate concerning this embodiment is explained.
The aluminum alloy sheet for can bodies according to the present embodiment is a melting, casting, homogenizing treatment, soaking, hot rolling, cold rolling, intermediate annealing, final cold, which is applied when manufacturing this type of aluminum alloy. It is manufactured through rolling. The final cold rolling reduction is preferably 55% or more and 75% or less. Further, it is preferable to perform intermediate annealing (continuous annealing) in which heating is performed to a temperature of 480 ° C. or more and 545 ° C. or less for 1 second or more and 30 seconds or less after hot rolling or during cold rolling.
In particular, Si, Cu, Mg, etc. are solutionized by continuous annealing in which heating is performed at 480 ° C. or more and 1 second or more, and precipitation hardenability is imparted, and thus after sufficient baking (210 ° C., 10 minutes) The material resistance of is obtained.

When the temperature of the intermediate annealing exceeds 545 ° C., the fuel consumption in the continuous annealing furnace becomes large, which is not preferable from the viewpoint of resource protection, and the surface of the material is easily oxidized, which is not preferable.
When the annealing time exceeds 30 seconds, the productivity is reduced. Therefore, the temperature of the intermediate annealing is preferably in the range of 480 ° C. to 545 ° C., and the time of the intermediate annealing is preferably in the range of 1 second to 30 seconds. If the cooling rate of the intermediate annealing is less than 10 ° C./s, productivity decreases, and precipitation of Si, Cu, Mg, etc. which has been solutionized in the intermediate annealing occurs, and bake hardability is lowered, so this is preferable. Absent. When the cooling rate of the intermediate annealing exceeds 200 ° C./s, the plate material tends to be distorted. Therefore, the cooling rate of the intermediate annealing is preferably 10 ° C. or more and 200 ° C./s or less.

  With regard to the rolling reduction at the final cold rolling, if the rolling reduction is less than 55%, sufficient work hardening by rolling can not be obtained, and the strength is insufficient. If it exceeds 75%, the as-rolled strength becomes high, so that molding defects such as wrinkles in cup molding and DI molding and barrel breakage in DI molding tend to occur, and the 45 ° ear becomes too high, and the formability deteriorates .

  The homogenization treatment can be performed on the aluminum alloy ingot in a temperature range of 560 ° C. to less than the melting point.

[Thickness of aluminum alloy sheet for can body]
It is preferable that the plate | board thickness of the aluminum alloy plate for can bodies of this invention is the range of 0.220 mm or more and 0.265 mm or less.
If the plate thickness is less than 0.220 mm, sufficient pressure resistance can not be obtained when making the can into a can body. In addition, when the thickness of the plate is more than 0.265 mm, the weight of the bottom of the can body is heavy, which increases the manufacturing cost and is not economical.

[Material strength after baking (210 ° C × 10 minutes)]
The can body after DI processing is heated to a temperature of 180 ° C. to 230 ° C. by washing after drying after chemical conversion treatment, baking after outer surface printing or inner surface coating. This heating generally changes the strength of the can bottom and body. The strength after heating varies depending on the amount of strain during DI molding. Since the distortion at the time of DI forming is small at the bottom, the strength after heating is almost equal to the strength after heating the aluminum alloy sheet which is the material before DI processing. For this reason, the strength after baking (heating) of the aluminum alloy plate which is a raw material can be used as a standard of the strength of the bottom. In the present embodiment, the heating condition for this is set to 210 ° C. × 10 minutes.

[YS value after baking and ASTS-ABYS value]
The value of YS after baking (ABYS) is preferably 280 MPa or more in yield strength after baking under the above conditions.
If the material proof stress after baking under the above conditions is less than 280 MPa, sufficient pressure resistance of the can body after can making by DI processing and paint baking can not be obtained.
[ASTS]
The as-rolled tensile strength (ASTS) is preferably 310 MPa or less. If the as-rolled tensile strength (ASTS) exceeds 310 MPa, molding defects such as wrinkling during drawing in cup forming and DI processing and breakage of a body part at the time of ironing tend to occur easily.

The value of ASTS-ABYS is preferably 10 MPa or less.
If the difference between the tensile strength of the material before baking and the yield strength of the material after baking is 10 MPa or less, it is necessary to simultaneously achieve high cup forming and DI formability and sufficient pressure resistance of the can body after making by baking paint. it can. If the difference between the tensile strength of the material before baking and the yield strength of the material after baking exceeds 10 MPa, the pressure strength of the can body after can making by baking can be insufficient under the condition of obtaining high cup forming and DI formability. In addition, when the pressure strength of the can body after can making by paint baking is increased, cup forming and DI formability become insufficient.

  In the aluminum alloy sheet for can bodies of the present embodiment, it is more preferable that the as-rolled material tensile strength (ASTS) is 300 MPa or less, and the post-baking proof stress (ABYS) is 285 MPa or more.

[About the total draw ratio and the total aperture ratio]
The aluminum alloy sheet for can bodies of the present invention is used for the production of can bodies. Moreover, the aluminum alloy sheet for can bodies of the present invention is used for the production of can bodies having a total ironing rate of less than 60% during DI processing. Here, the total ironing rate is expressed by the following equation (1).
Total ironing ratio (%) = {(original board thickness T1-final can body trunk thinnest part thickness T2) / original board thickness T1} × 100 (1)
In the above equation (1), the final can body barrel thinnest portion thickness T2 is a thickness without a coating. The aluminum alloy sheet for can bodies of the present invention preferably has a thickness of 0.220 mm or more and 0.265 mm or less.

Here, if the overall ironing ratio is set to a value exceeding 60%, the aluminum alloy sheet for can bodies of the present invention has high material strength, so that barrel breakage easily occurs at the time of ironing and productivity is reduced.
When the material plate thickness is smaller than 0.220 mm, sufficient pressure resistance can not be obtained. If the thickness of the trunk is too large, although the pinhole resistance is improved, the strength is too high from a practical standpoint and the amount of the required material increases, which is not economical. Therefore, the total ironing rate needs to be 60% or less.
Moreover, the aluminum alloy sheet for can bodies of the present invention is used for the production of can bodies having a total drawing ratio of 2.0 to 2.7 at the DI processing.
If the total drawing ratio is larger than 2.7, the material is likely to be broken during drawing if it is squeezed in two drawing processes. On the other hand, in order to obtain a can body of practical capacity under the restriction of the material plate thickness T1, the final can body trunk thinnest part thickness T2, and the total ironing rate, the total drawing ratio is set to 2.2 or more. There is a need to. For example, in the case of forming a can body having a can body diameter of 66 mm and a capacity of 350 cc, which is generally used, it is preferable to set the total drawing ratio to 2.2 to 2.4. When a can body having a can body diameter of about 66 mm and a capacity of about 500 cc is to be formed, the total drawing ratio is preferably set to 2.45 to 2.65.

Here, the total drawing ratio A is obtained by multiplying the cup drawing ratio B (steps in FIGS. 1A and 1B) by the redrawing ratio C (steps in FIGS. 1B to 1C). It is a value and is represented by following Formula (2)-(4).
Cup aperture ratio B = blank diameter D1 / cup diameter D2 (2)
Redrawing ratio C = cup diameter D2 / body diameter D3 (3)
Total drawing ratio A = cup drawing ratio B × redrawing ratio C = blank diameter D1 / body diameter D3 (4)

[Can-making process by DI processing]
Hereinafter, an example of the process of obtaining a can body 10 by performing DI processing on an aluminum alloy material for a can body by using FIG. 1 will be described.
First, as shown in FIG. 1A, the can body aluminum alloy material is subjected to punching to obtain a disk-shaped plate material (blank) 5 having a diameter of 149 mm.
Then, the disk-shaped plate material is drawn to form a cup-shaped can 6 having a height of 42 mm in the axial direction and an outer diameter of 88.2 mm as shown in FIG. 1 (b).

Next, the cup-shaped can 6 is redrawn to obtain a cup-shaped can 7 having an outer diameter of 66 mm as shown in FIG. 1 (c). Here, the ratio of D1 to D3 is set to 2.2 to 2.7.
Next, ironing is performed so that the total ironing rate is less than 60%, and a bottomed cylindrical can 8 as shown in FIG. 1D is formed. The open end of the bottomed cylindrical can 8 has an uneven shape that undulates in the can axis direction.

  Then, the open end of the bottomed cylindrical body shown in FIG. 1 (d) is cut to make the size in the can axis direction, that is, the height equal to about 123.5 mm over the entire circumference, A can body 10 having a circular cross section shown in FIG. 1 (e) having a body 11 and a bottom 12 with a diameter of 65 mm or more and 67 mm or less is formed.

As described above, according to the aluminum alloy sheet for can bodies of the present embodiment, the tensile strength (ASTS) of the as-rolled material is 310 MPa after the component composition is in the above-mentioned range and the amount of Mn is particularly suppressed low. Hereinafter, an aluminum alloy sheet for can bodies can be provided which has a proof stress (ABYS) after baking of 280 MPa or more and a difference between as-rolled tensile strength (ASTS) and bake strength (ABYS) of 10 MPa or less.
With this aluminum alloy sheet for can bodies, when the can body is manufactured by DI forming, good formability can be maintained at the time of DI forming, and therefore cans can be produced without causing body breakage, and cans can The tensile strength can be increased by the bake-hardening property accompanying the subsequent heating, and the can body excellent in can body strength can be provided.
Therefore, the can body excellent in can body intensity can be obtained by using the aluminum alloy plate for can bodies of this embodiment, without increasing manufacturing cost.

EXAMPLES The aluminum alloy sheet for can bodies according to the present invention, which is excellent in flow resistance pinhole resistance, will be described in more detail below by way of examples, but the present invention is not limited to the following examples.
In this example, aluminum alloy sheets for can bodies No. 1 to No. 20 were manufactured in the following steps under the respective component compositions and manufacturing conditions shown in Table 1 below, and evaluations were made on each item described later. .

[Production process of aluminum alloy sheet for can body]
An aluminum alloy containing the components shown in Table 1 below is melted, this molten metal is degassed and inclusions are removed by a conventional method, and a slab of 550 mm in thickness, 1.5 m in width, and 4.5 m in length by semi-continuous casting. I cast several. Next, each slab was homogenized at a temperature of 565 ° C. and then subjected to hot rolling. It was rolled to a plate thickness of 20 mm by hot rolling, and then to a plate thickness of 3 mm using a hot finishing mill, and then cold rolled to a plate thickness of 0.65 mm.
Thereafter, continuous annealing (IA-CAL) of heating for 20 seconds in a temperature range of 450 ° C. to 555 ° C. is applied in the course of cold rolling, and cold rolled to a final thickness of 0.240 mm. A sample was obtained.
No. The 12 samples were hot-rolled to a plate thickness of 20 mm in the same manner as described above, then hot-rolled to a plate thickness of 2.3 mm using a hot finish rolling mill, and then introduced into a batch furnace. After annealing at a temperature of ° C., it was obtained by cold rolling to a thickness of 0.240 mm.

  Also, for each sample of aluminum alloy sheet for can bodies, JIS No. 5 test pieces are collected so that the tensile direction is parallel to the rolling direction, and the material is subjected to the tensile test as it is to measure the tensile strength, and after baking For the material of (1), 0.2% proof stress was measured after heating at 210 ° C. for 10 minutes (after baking).

[Can of can body]
The aluminum alloy sheet for can bodies of each of the examples and the comparative examples obtained in the above-described process was punched out to obtain a disc-shaped plate (see FIG. 1A) having a diameter of 149 mm. DI processing was applied to this disk-shaped plate material to obtain a can body (350 cc can).

  A hot air circulating furnace as an alternative to heat treatment at the time of drying after cleaning, chemical conversion treatment, baking after outer surface printing or inner surface coating for the can bodies of each of the Examples and Comparative Examples subjected to DI processing as described above Heat treatment at 210 ° C. × 10 min.

[Evaluation item of can body]
After sealing the mouth of the can, pressure was applied to the can, and the pressure when the bottom of the can was buckled was measured as "bulge strength". A sample with a bulge strength of 540 kPa or more was rated as ◎, a sample with 500 kPa or more and less than 540 kPa as ○, and a sample less than 500 kPa as ×.

[Evaluation of cut-off ability]
First, 50,000 cans were continuously formed, and it was examined whether or not breakage of the body occurs during ironing. A sample in which the incidence of cylinder breakage was more than 0 ppm and 40 ppm or less was regarded as x, and a specimen in which the incidence of cylinder breakage was more than 40 ppm was regarded as xx. For samples that did not have a barrel cut, the sample was further molded to 50,000 can, and a sample that had a cylinder cut rate of more than 0 ppm but not more than 20 ppm in a total of 100,000 cans was molded A sample in which no torn was generated was marked ◎.

Table 1 shows the composition components, manufacturing conditions and evaluation test results of each example and comparative example.
In addition, CAL temperature of Table 1 shows the temperature at the time of performing continuous intermediate annealing between cold rolling and cold rolling in an alloy plate preparation process, and with batch annealing, it winds in the shape of a coil. Indicates that the sample was annealed.

  From the test results shown in Table 1, the conditions desired in the present invention, that is, Si: 0.25 to 0.45%, Fe: 0.3 to 0.55%, Cu: 0.2 to 0.% by mass. An aluminum alloy sheet for can bodies containing 45%, Mn: 0.30 to 0.78%, Mg: 1.0 to 1.5% and the balance comprising Al containing unavoidable impurities, which is rolled An aluminum alloy sheet with a raw material tensile strength (ASTS) of 310 MPa or less, a post-baking yield strength (ABYS) of 280 MPa or more, and a difference between the as-rolled base tensile strength (ASTS) and the post-baking strength (ABYS) of 10 MPa or less If it is (samples of No. 9, 10, 15 to 17 and 19), it is possible to provide a can body having high strength even after baking without forming problems such as good moldability during DI molding and no barrel breakage. Recognize.

On the other hand, the samples No. 1 to No. 8 contain a large amount of Mn, adjust the amount of Mg, and change the CAL temperature as appropriate. However, the value of ASTS is large or the value of ABYS Is a small sample, and the value of ASTS-ABYS is as large as 14-31. The samples No. 1 to 3 and 6 had small values of ABYS and lacked can body strength. The sample of No. 5 had a large value of ASTS, and the torso occurred. The samples No. 7 and 8 had large values of ASTS, and the torso occurred. In the sample No. 11, the appearance property was deteriorated due to the progress of surface oxidation, and the value of ASTS was large, and the torso occurred.
The sample No. 12 was a batch-annealed sample, but a large number of cuts occurred.
The sample No. 13 is a sample in which the amount of Mn is lowered, but the value of ABYS decreases, and the sample of No. 14 is a sample in which the CAL temperature is lowered, but the value of ABYS decreases.
The sample of No. 18 is a sample with a low CAL temperature, the value of ABYS decreases, the sample of No. 20 is an example in which the Mn content is slightly higher than the desirable range, the value of ASTS increases, and the ASTS- The value of ABYS has increased.

  5 plate material, 6, 7 cup-shaped can body 8 bottomed cylindrical can body 10 can body 11 body part 12 bottom part.

Claims (3)

Si: 0.25 to 0.45%, Fe: 0.3 to 0.55%, Cu: 0.2 to 0.45%, Mn: 0.30 to 0.78%, Mg: in mass% It is an aluminum alloy sheet for can bodies containing 1.0 to 1.5% and the balance of Al containing inevitable impurities,
The as-rolled material tensile strength (ASTS) is 310 MPa or less, the post-baking yield strength (ABYS) is 280 MPa or more, and the difference between the as-rolled base material tensile strength (ASTS) and the post-baking yield strength (ABYS) is 10 MPa or less Aluminum alloy sheet for can body that is characterized.   The aluminum alloy sheet for can bodies according to claim 1, wherein the as-rolled material tensile strength (ASTS) is 300 MPa or less, and the post-baking proof stress (ABYS) is 285 MPa or more. Si: 0.25 to 0.45%, Fe: 0.3 to 0.55%, Cu: 0.2 to 0.45%, Mn: 0.30 to 0.78%, Mg: in mass% An aluminum alloy ingot containing 1.0 to 1.5% and the balance consisting of Al containing unavoidable impurities is subjected to homogenization treatment and soaking treatment, then subjected to hot rolling and cold rolling, and continuously annealed Then, it is a method of performing final cold rolling and manufacturing an alloy sheet for aluminum for can bodies,
The continuous annealing is performed under the conditions of a heating rate of 10 to 200 ° C./sec, a holding temperature of 480 to 545 ° C., a holding time of 1 to 30 seconds, and a cooling rate of 10 to 200 ° C./sec. 75% ,
The as-rolled material tensile strength (ASTS) of the can body aluminum alloy sheet obtained after the final cold rolling is 310 MPa or less, the post-baking yield strength (ABYS) is 280 MPa or more, and the as-rolled material tensile strength (ASTS) A method for producing an aluminum alloy sheet for can bodies, comprising producing an aluminum alloy sheet for can bodies having a difference in proof stress (ABYS) after baking of 10 MPa or less .

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