JPH10330896A - Production of aluminum base alloy sheet for deep drawing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an aluminum base alloy sheet for deep drawing in which not only the earing ratio at the time of deep drawing can remarkably be reduced, but also neck earing is hard to occur even in the case the reduction rate of the neck is made high at the time of can making by using a reverse type hot rough rolling mill of a single mill in all stages of a hot rolling stage. SOLUTION: In (1) a soaking stage, an aluminum base alloy ingot is heated at 520 to 610 deg.C, in (2) a hot rolling stage, hot rolling is executed so as to regulate the sheet material temp. upon the end of the hot rolling to 280 to 350 deg.C, and in (3) a primary cold rolling stage, cold rolling is executed so as to regulate the rolling ratio to 60 to 90%. Then, in (4) a primary process annealing stage, annealing is executed at 250 to 280 deg.C for 2 to 24 hr, in (5) a secondary cold rolling stage, cold rolling is executed so as to regulate the rolling ratio to 5 to 30%, in (6) a secondary process annealing stage, annealing is executed at 270 to 400 deg.C for 2 to 24 hr, and then, in (7) a final cold rolling stage, cold rolling is executed at 70 to 90% rolling ratio.

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 an aluminum-base alloy plate for deep drawing, which has high strength and high ductility and can significantly reduce the ear ratio in deep drawing of aluminum-based alloy cans and the like. About.

[0002]

2. Description of the Related Art With an increase in demand for canned beverages and the like, recently, so-called DI (Deep drawing & Ironing) cans made of an aluminum-based alloy suitable for the containers have been mass-produced. This DI made of aluminum base alloy
As a general method of manufacturing the main body of the can, an aluminum-based alloy plate is deep-drawn in multiple stages, then ironed to form the main body of the can, and after baking coating, the pressure resistance is improved and a relatively expensive lid is formed. Neck processing is performed to reduce the diameter in order to reduce the amount of material used for the member. The aluminum-based alloy sheet used here is required to have both sufficient strength after can making and formability to withstand multi-stage deep drawing and ironing.

In general, as an aluminum-based alloy for deep drawing, an Al-Mn-Mg-based alloy such as the American Aluminum Association Standard (AA) 3004 alloy is widely used. In order to produce a deep-drawing aluminum-based alloy sheet from this alloy, (a) first hot-roll an ingot of this alloy, and then (b) cold-roll to obtain a sheet material having an appropriate thickness. The sheet material after cold rolling is subjected to (c) intermediate annealing, and further subjected to (d) cold rolling hardening treatment according to the required strength.

In the manufacturing process of the aluminum-base alloy sheet for deep drawing, in order to improve the strength of the sheet material, it is necessary to increase the cold rolling rate in the cold rolling (d). However, when the degree of cold rolling is increased, a so-called rolling texture develops, anisotropy appears remarkably at the time of plastic deformation, and according to the rolling direction of the sheet material at the time of deep drawing, the shape of the formed can body is A phenomenon occurs in which the height of the upper edge changes in a valley-like manner. This part that has been deformed into a mountain valley is usually
They are called "ears". The can body after deep drawing is then ironed, and then trimmed to cut the opening horizontally to make the can height uniform in order to attach a lid member.
Ears are also removed during this trimming, so if the height of the ears is high, the amount of plate material to be removed (hereinafter referred to as "ear ratio") increases, the yield decreases, and the manufacturing cost increases. There was a problem of doing. Therefore, a plate material having a low ear ratio was required.

In general, when an aluminum-based alloy plate is cold-rolled, a rolled texture tends to develop in the direction of 45 to 60 ° with respect to the rolling direction. Therefore, in order to reduce the ear ratio, it is necessary to suppress the development of the rolling texture. It has been found that this can be achieved by controlling the state of formation of the recrystallized texture in the sheet material before cold rolling. That is, generally, before cold rolling, 0
A method of developing a recrystallized texture called "cubic orientation" that produces a deep drawing ear in a direction of ~ 90 ° is used. The development of the cubic orientation results in ears in the 0-90 ° direction, but the subsequent cold rolling does not develop much in the ears, while the development of the rolled texture producing the 45 ° ears is also suppressed. As a result, the peak of the ear at the periphery of the opening is leveled. According to this method, after cold rolling at a rolling degree of 80% or more, a slight
It has become possible to obtain a low-ear plate material in which 0 ° ears and 45 ° ears coexist.

As a specific method for developing the recrystallized texture having the cubic orientation, various conditions during hot rolling are adjusted, and the coil wound after hot rolling is cooled or cooled. Method for controlling recrystallization generated when annealing a coil taken (Japanese Patent Laid-Open No. 5-125500)
It has been known. In this method, (b) cold rolling,
Alternatively, (d) cold rolling is performed on the recrystallized hot rolled sheet without performing (b) cold rolling and (c) intermediate annealing. At present, the thickness of the sheet material mainly used for DI cans is about 0.3 mm, so when applying this method to make the final cold rolling reduction 80 to 90%, the heat It is necessary to perform rolling so that the sheet thickness becomes 1.5 to 3 mm by cold rolling. Therefore, usually, using a reverse type hot rolling mill, and further rolling using a tandem type finishing hot rolling mill or a reverse type hot finishing mill equipped with a coil winding device on both sides of the rolling mill. A method is used. However, these hot finishing mills are large and expensive,
The use of this method imposes a heavy burden on manufacturing costs.
Furthermore, as the thickness of the material for cans becomes thinner, the effect of the temperature drop between the rolling rolls and passes increases, and it is necessary to further increase the equipment capacity in order to maintain appropriate hot rolling conditions. Tended to increase.

Therefore, a method using only a single-mill reverse hot rough rolling mill in all the steps of hot rolling was studied. However, when attempting to produce thin-walled sheet material using this rough rolling mill, the temperature drop between passes is remarkable, and it is extremely difficult to maintain hot rolling conditions for controlling recrystallization of a hot-rolled sheet. Become. As a means for solving this problem, an element that imparts age hardening to the aluminum-based alloy is added, and after the cold rolling of the above (b), the intermediate annealing of the above (c) is performed at a relatively high temperature to form a solution, A method has been proposed in which sufficient strength can be obtained even when the rolling degree of the cold rolling in the above (d) is reduced (Japanese Patent Publication No. 60-35242).

According to this method, since the crystals are precipitated by heating the baking coating after forming the DI can body, softening due to heating during baking is suppressed, and sufficient strength is obtained even if the cold rolling reduction is reduced. Can be obtained. Therefore, even if the cubic texture is not sufficiently developed after the intermediate annealing (c), the rolling reduction of the cold rolling can be reduced, so that the development of the rolled texture becomes light and the DI ratio at a practical level where the ear ratio is relatively low is reduced. Cans are now available. This method has a slightly higher ear ratio than in the case of using a finishing hot rolling mill, and therefore has a large amount of trim, but can be applied without using an expensive finishing hot rolling mill with high equipment cost. As a result, this is an advantageous method.

[0009]

However, recently, the demand for reducing the diameter of the lid member in the DI can has increased due to economical and design requirements, and as a result, the neck diameter reduction rate has increased. . However, when the diameter reduction ratio of the neck is increased, a new problem arises in that the can height changes in the opening due to the anisotropy of the material in the neck forming step as well as in the case of the deep drawing forming, and ears are generated. .
The height variation of the opening caused by the neck forming is called "neck ear".

The opening of the main body of the can is formed into a flange after the neck is formed. This flange is used for tightening with the lid member. Problems such as a change in the shape of the portion depending on the direction occur, which complicates the processing step and adversely affects the appearance. Therefore, there has been a demand for an aluminum-based alloy plate for deep drawing which hardly causes a neck ear even when the diameter reduction ratio of the neck is increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and accordingly, it is an object of the present invention to provide a deep drawing using a single-mill reverse hot rough rolling mill in all of the hot rolling processes. An object of the present invention is to provide a method of manufacturing an aluminum-based alloy plate for deep drawing, which can significantly reduce ear ratio during forming.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a method for manufacturing an aluminum-based alloy plate from an aluminum-based alloy ingot, wherein the aluminum-based alloy From 520 to 61
Heating to a homogenization temperature in the range of 0 ° C. to homogenize, and in a hot rolling step, the homogenized aluminum-based alloy ingot is hot-rolled to form a sheet material, The sheet material temperature is adjusted to a temperature range in which the sheet material does not recrystallize within a range of 280 to 350 ° C., and in the first cold rolling step, the sheet material after the completion of the hot rolling has a rolling reduction of 60 to
Cold rolling is performed so as to be within a range of 90%, and in the first intermediate annealing step, the sheet material after the cold rolling is performed at an annealing temperature within a range of 250 to 280 ° C and an annealing time of 2 to 24 hours. In the second cold rolling step, in the second cold rolling step, the sheet material after the first intermediate annealing is cold-rolled so that the rolling ratio is in the range of 5 to 30%, and in the second intermediate annealing step,
The sheet material after the second cold rolling is performed at an annealing temperature of 270 to 40.
In the range of 0 ° C., the annealing time is in the range of 2 to 24 hours, and then, in the final cold rolling step, the sheet material after the second intermediate annealing has a rolling reduction in the range of 70 to 90%. To provide a method for producing an aluminum-based alloy plate for deep drawing by cold rolling as described above.

The aluminum-based alloy contains 0.1 to 0.4% by weight of Si, 0.3 to 0.6% by weight of Fe, 0.05 to 0.4% by weight of Cu, and Mn: 0.1 to 0.4% by weight. It is preferable that the composition contains 8 to 1.5% by weight and Mg: 0.8 to 1.5% by weight, with the balance having a composition consisting of Al and unavoidable impurities. The aluminum-based alloy preferably further contains Cr: 0.25% by weight or less, Zn: 0.05 to 0.25% by weight, and Ti: 0.2% by weight or less, in addition to the above elements. .

In the above-mentioned soaking step, it is preferable that the homogenizing heating rate is 100 ° C./hour or less and the homogenizing time is 1 hour or more. In the hot rolling step, it is preferable to use a single-mill reverse hot rough rolling mill in all the steps of hot rolling. Also in this process,
The hot rolling start temperature is preferably 500 ° C. or more, and the starting temperature of the final hot rolling pass is preferably 400 ° C. or more. The rolling reduction in the final hot rolling pass is preferably set to 50% or more. In the second cold rolling step, it is preferable that the sheet material after the first intermediate annealing is cold-rolled so that a rolling reduction falls within a range of 10 to 20%. In the second intermediate annealing step, the sheet material after the second cold rolling,
It is preferable to keep the annealing temperature within the range of 270 to 320 ° C for 1 to 12 hours.

[0015]

Embodiments of the present invention will be described below in detail. The method for producing an aluminum-based alloy sheet for deep drawing (hereinafter, referred to as “the present alloy sheet”) of the present invention (hereinafter, referred to as “the present production method”) basically uses an ingot of an aluminum-based alloy as a base material, Each of the following steps set to specific conditions: soaking, hot rolling, first cold rolling, first intermediate annealing, second cold rolling, second intermediate annealing, and final cooling It is constituted by sequentially passing through the inter-rolling process.

According to the present production method, a single-mill reverse hot rough rolling mill alone is used in all of the hot rolling steps, and the present alloy sheet having both strength and formability can be obtained. When used as a plate material for manufacturing deep drawn cans, the ear ratio is reduced as compared with conventional plate materials, and the neck ears are reduced even when molding DI cans with a large neck diameter reduction ratio, which reduces the deformation of the can body. This can improve the yield.

The aluminum-based alloy composition (hereinafter referred to as "the present composition") used in the present production method is basically based on Al, containing 0.1 to 0.4% by weight of Si and 0.3% by weight of Fe. ~
A material containing 0.6% by weight, 0.05 to 0.4% by weight of Cu, 0.8 to 1.5% by weight of Mn, and 0.8 to 1.5% by weight of Mg is used. Since the basic composition itself is not special and falls within the range of the composition of various aluminum can alloys currently being used in large quantities, this production method uses recycled aluminum cans as raw materials. It is suitable for efficiently and efficiently producing the present alloy sheet. Among them, Si easily forms a compound with simultaneously contained Mg, and has a solid solution hardening action, a dispersion hardening action, and a precipitation hardening action, and also forms a compound with Al, Mn, Fe, etc., and forms a die with ironing. It has the effect of preventing image sticking. If the content is less than 0.1% by weight, desired lubricating properties cannot be ensured, and if it exceeds 0.4% by weight, workability is deteriorated, which is inconvenient. Fe has an effect of miniaturizing the crystal and preventing seizure on a die during ironing. If the content is less than 0.3% by weight, the desired effect cannot be obtained, and if it exceeds 0.6% by weight, the workability is deteriorated. Cu easily forms a compound with Mg and contributes to solid solution hardening, dispersion hardening, and precipitation hardening. If the content is less than 0.05% by weight, the desired effect cannot be obtained, and if it exceeds 0.4% by weight, the workability is deteriorated. M
n easily forms a compound with Fe, Si, Al and the like, has a crystallized phase and a dispersed phase, exhibits a dispersion hardening effect, and has an effect of preventing seizure to a die during ironing. If the content is less than 0.8% by weight, desired curing properties cannot be obtained, and if it exceeds 1.5% by weight, processability is deteriorated. Mg has a solid solution strengthening effect, enhances work hardenability by rolling, and exhibits a dispersion hardening and a precipitation hardening effect by coexisting with Si and Cu. If the content is less than 0.8% by weight, the desired effect cannot be obtained.
If it exceeds 5% by weight, the effect will be reduced again.

The composition of the present invention contains Si, Fe, Cu, M
0.25% by weight of Cr in addition to n and Mg
Hereinafter, 0.05 to 0.25% by weight of Zn and 0.2% of Ti
It may be contained within the range of not more than% by weight. Of these, Cr
Has an action of suppressing recrystallization after hot rolling. However, if the content exceeds 0.25% by weight, this effect is rather reduced. Zn has an action of miniaturizing precipitates of Mg, Si, and Cu. If the content is less than 0.05% by weight, the desired effect cannot be obtained, and if it exceeds 0.25% by weight, the corrosion resistance deteriorates. Ti has the effect of making crystal grains finer and improving workability. However, if the content exceeds 0.2% by weight, a coarse compound is formed and processability is deteriorated.

In producing the present alloy sheet from the present composition, first, an ingot is cast from a molten metal of the present composition according to a conventional method. The solidification rate at this time is usually 5 to 20 ° C./sec. The size of the ingot is, for example, 1.5mx 0.5mx
4 to 5 m. Next, the surface of the ingot is cut by 1-2 mm.
Grind about 5 mm to create a chamfer with a smooth surface.

This chamfer is then sent to the soaking step of the present invention. In general, this soaking process is used to homogenize microsegregation caused by solidification of molten metal, precipitate supersaturated solid solution elements,
This is performed for the purpose of, for example, transferring a metastable phase formed by solidification to an equilibrium phase. In this soaking process, it is important that the homogenization temperature be in the range of 520 to 610 ° C. When the homogenization temperature is lower than 520 ° C., the effect of the second intermediate annealing cannot be obtained, and the ear ratio becomes high. If the temperature exceeds 610 ° C., the ingot melts.

In the above-mentioned soaking step, the chamfered body is preferably heated to a homogenizing temperature at a heating rate of 100 ° C./hour or less. When the heating rate exceeds 100 ° C / hour,
There is a risk of partial melting. But the heating rate is
If it is too slow, production efficiency will decrease. From this viewpoint, a preferable heating rate is in the range of 10 to 100 ° C./hour.

In the above soaking step, the time for maintaining the temperature at the homogenization temperature (homogenization time) is preferably 1 hour or more. If the homogenization time is less than 1 hour, the homogenization may not proceed sufficiently. However, if it is too long, there is no effect and the production efficiency is reduced. From this point of view, the preferred homogenization time is in the range of 1 to 24 hours. This soaking step is usually carried out in a batch mode in a furnace due to the relatively long homogenization time.

The hot rolling step is performed to hot-roll the homogenized aluminum-based alloy ingot to form a sheet material. The present invention is characterized in that this hot rolling step can be performed using only a single-mill reverse hot rough rolling mill. This rolling mill is provided with a seat before and after a single-base type hot rolling roll, and gradually thinner by repeatedly passing the ingot reciprocatingly between the hot rolling rolls, as a conventional hot rough rolling mill. This is a commonly used device.

In the hot rolling step, it is particularly important to prevent the sheet material wound as a coil from recrystallizing after the completion of the rolling. For this purpose, the temperature of the coil immediately after the end of the hot rolling is adjusted to be in the range of 280 to 350 ° C. When this finishing temperature is cooled to less than 280 ° C., the sheet material becomes hard and cracks are likely to occur during the subsequent cold rolling. After winding on a coil,
If it exceeds 50 ° C., recrystallization occurs in the wound plate material.

In the hot rolling step, the rolling start temperature is preferably set to 500 ° C. or higher. If the rolling start temperature is lower than 500 ° C., the rolling load increases, the number of required passes increases, the efficiency decreases, and it becomes difficult to maintain the allowable temperature range immediately after the end of the hot rolling. The starting temperature of the final pass is preferably set to 400 ° C. or higher. The rolling ratio in the final pass of this hot rolling step is 50.
% Or more, and the strain rate is preferably in the range of ¹ to 50 sec ^-1 . The higher the starting temperature, rolling ratio, and strain rate of the final hot rolling pass, the higher the production efficiency, but the sheet temperature immediately after hot rolling may be higher than the specified temperature. In this case, the sheet material is forcibly cooled between the rolling rolls and the coil winder so that the temperature of the sheet material wound around the coil immediately after the completion of the hot rolling is in the range of 280 to 350 ° C. Is preferred.

In the first cold rolling step, the cooled sheet material after the completion of the hot rolling step is cold-rolled so that the rolling ratio falls within the range of 60 to 90%. If the rolling ratio in this step is less than 60%, the ear ratio becomes large. The higher the rolling reduction, the more cubic orientation structures having 0-90 ° ears are generated in the second intermediate annealing step. However, when the rolling ratio exceeds 90%, the ear ratio is conversely increased and side cracks also occur. From this viewpoint, the rolling reduction is preferably in the range of 75 to 90%.

In the first intermediate annealing step, the sheet material after the cold rolling is annealed at an annealing temperature in a range of 250 to 280 ° C. and an annealing time in a range of 2 to 24 hours. This step brings the sheet material to a semi-softened state. If the tensile strength before annealing is TSH, the tensile strength of the fully annealed material is TSO, and the tensile strength after semi-softening annealing is TS, then (TSH Annealing is performed so that the value of (−TS) / (TSH−TSO) × 100 (%) falls within the range of 40 to 90%. In this step, it is preferable to use a batch type annealing furnace in relation to the annealing time. The heating rate is (set annealing temperature−10
From 0 ° C.) to (set annealing temperature −10 ° C.), the average is preferably 5 to 20 ° C./hour. Annealing temperature 25
If the temperature is less than 0 ° C. or the annealing time is less than 2 hours, sufficient softening cannot be obtained, and the ear ratio becomes high. If the annealing temperature exceeds 280 ° C. or the annealing time exceeds 24 hours, the softening becomes excessive and the ear rate increases.

The second cold rolling step is a step of cold rolling the sheet material after the first intermediate annealing so that the rolling ratio is in the range of 5 to 30%. Actually, the rolling rate is 10
Within the range of 20%, the ears at 0-90 ° were found to be highest. If the rolling ratio is less than 5%, the number of rolling passes in the entire process increases, and the production efficiency may decrease, which is not preferable. When the rolling ratio exceeds 30%, the ear ratio increases, and there is no reason to use the present production method.

The second intermediate annealing step is a step of annealing the sheet material having undergone the above-mentioned second cold rolling step at an annealing temperature of 270 to 400 ° C. and an annealing time of 2 to 24 hours. . This step is a step of completely recrystallizing the plate material which has been subjected to the above-described steps in order, fully developing a cubic orientation structure, and obtaining a soft material having a high 0-90 ° ear. At this time, after the sheet material having undergone the second cold rolling step is first held at an annealing temperature in the range of 270 to 320 ° C for 1 to 12 hours, annealing is further performed at a higher temperature in the range of 270 to 400 ° C. This proved that the ear ratio could be further improved. The application of this temperature difference may be performed in two or more stages, or 270-400 ° C.
The temperature may be raised continuously within the range described above. Lower limit of annealing temperature 2
The heating rate to reach 70 ° C is from 150 ° C to 270 ° C.
It is preferable that the average is 10 to 25 ° C / hour up to ° C.
If the annealing temperature is less than 270 ° C. or the annealing time is less than 2 hours, the effect of annealing is insufficient, and the ear rate improving effect cannot be obtained. If the annealing temperature exceeds 400 ° C. or the annealing time is 24
Even if the time is exceeded, the ear ratio is not further improved, the production efficiency is reduced, and adverse effects such as surface oxidation are likely to occur.

In the final cold rolling step, the sheet material after the above-mentioned second intermediate annealing is cold-rolled in a rolling ratio of 70 to 90% so as to have a predetermined sheet thickness. After passing through this step, the sheet material is wound into a coil as a main alloy sheet having a predetermined thickness and commercialized. If the rolling ratio in this step is less than 70%, the production efficiency is increased, but work hardening is likely to occur at the time of can molding or neck molding. When the rolling ratio exceeds 90%, the ear ratio increases.

[0031]

Next, the present invention will be described in more detail with reference to examples. In the following Examples and Comparative Examples, four types of compositions shown in Table 1 were used as raw materials of aluminum-based alloys,
These were used as alloys A, B, C, and D, respectively.

[0032]

[Table 1]

An ingot having a weight of 6 t and a thickness of 550 mm was cast from the melt of each of the above alloys by semi-continuous casting.
A sample of a chamfered ingot was prepared by 2.5 mm facing. With respect to each of the samples, the examples were sequentially subjected to the soaking step, the hot rolling step, and the comparative example under the conditions shown in Table 1 and Table 2, respectively.
The first cold rolling step, the first intermediate annealing step, the second cold rolling step, the second intermediate annealing step and the final cold rolling step were performed to produce an aluminum-based alloy sheet for deep drawing. Conditions of each step other than the notation were as follows for all samples. Soaking process: The heating rate was 50 ° C./hour on average, the homogenization temperature was 570 ° C. ± 3 ° C., and the homogenization was carried out by keeping the temperature in this temperature range for 8 to 10 hours. Hot rolling step: The sample immediately after the completion of the soaking step was performed using only a single-mill reverse hot rough rolling mill. The starting temperature of the final hot rolling pass was 450 ° C., and the rolling reduction was 62%. "Temperature immediately after hot rolling and winding" in Tables 1 and 2 is the temperature immediately after winding into a coil after the final pass, and was adjusted by the rolling speed (the lower the rolling speed, the lower the finishing temperature). First intermediate annealing step: The average heating rate from (set annealing temperature −100 ° C.) to (set annealing temperature −10 ° C.) is 12 to
14 ° C./hour. Cooling after the end of annealing is carried out when the actual temperature is about 2
Cooling was performed in a furnace until the temperature reached 50 ° C., and thereafter cooling was performed in the air. Second intermediate annealing step: Using a batch annealing furnace, the average heating rate from (set annealing temperature −100 ° C.) to (set annealing temperature −10 ° C.) was 14 to 17 ° C./hour. After the annealing, cooling was performed in a furnace until the actual temperature reached about 250 ° C., and thereafter, cooling was performed in the atmosphere. However, * in Tables 2 and 3
In the case of the mark, heating was performed at an average rate of about 15 ° C./hour from 250 ° C. to 290 ° C., and from 290 ° C. to 310 ° C.
To an average temperature of about 5 ° C / hr.
To (set temperature −10 ° C.) at a rate of about 15 ° C./hour. Final cold rolling step: An aluminum-based alloy plate for deep drawing with a plate thickness of 0.28 mm was manufactured according to the “final cold rolling ratio” in Tables 1 and 2.

A deep drawing test was performed using the above-mentioned aluminum base alloy plate for deep drawing. The “ear ratio” was calculated from the following formula: ear ratio = ear height ÷ cup height × 100 (%) for a cup drawn by deep drawing. The yield strength corresponds to the baking conditions for baking the aluminum-based alloy plate for deep drawing.
After heating at 10 ° C. for 10 minutes, it was processed into a JIS No. 5 tensile test piece, and the 0.2% proof stress was determined according to JIS B7771. The results are shown in Table 2 (Example) and Table 3.
(Comparative Example)

[0035]

[Table 2]

[Table 3]

From the results of Tables 2 and 3, the aluminum-based alloy plates for deep drawing of Examples 1 to 10 satisfying the conditions of the present invention (described in Table 1) all maintained excellent proof stress. As it was, a low ear rate of 1.5 to 2.8% was shown.
In contrast, in Table 3, Comparative Example 5 in which the temperature immediately after hot rolling and winding in the hot rolling step deviated from the conditions of the present invention;
Comparative Examples 3 and 4 in which the "first cold rolling rate" in the first cold rolling step deviated from the condition of the present invention; "Second cold rolling rate" in the second cold rolling step was out of the condition of the present invention. Comparative Example 1, which was out of order; and Comparative Example 6, in which the first intermediate annealing step and the second cold rolling step were omitted according to the conventional method of manufacturing an aluminum-based alloy sheet for deep drawing, had an ear ratio of 3.7. ~
6.2, which is remarkably inferior to Examples 1 to 10.

[0037]

According to the method for producing an aluminum-based alloy sheet for deep drawing according to the present invention, the aluminum-based alloy ingot is heated to 520 to 610 ° C. in the soaking step, Plate temperature is 280-350 ° C
Hot rolling so that the rolling rate becomes 60 to 90% in the first cold rolling step, and 250 to 280 ° C. for 2 to 24 hours in the first intermediate annealing step. In the second cold rolling step, cold rolling is performed so that the rolling reduction becomes 5 to 30%, and in the second intermediate annealing step, annealing is performed at 270 to 400 ° C. within a range of 2 to 24 hours. Since cold rolling is performed so that the rolling ratio is 70 to 90% in the final cold rolling step, the entire hot rolling step is performed using only a single-mill reverse hot rough rolling mill, and Not only can the ear ratio be significantly reduced during drawing, but also aluminum base alloy plates for deep drawing can be manufactured that do not easily cause neck ears even when the neck diameter reduction ratio is increased during can manufacturing, and DI cans are manufactured. Production costs and Stays can be significantly improved.

────────────────────────────────────────────────── ─── front page continued (51) Int.Cl. ⁶ identifications FI C22F 1/00 623 C22F 1/00 623 630 630K 682 682 683 683 684 684A 685 685Z 686 686B 691 691B 691C 691A 694 694A 694B (72) Inventor Mitsuru Saito 85 Hiramatsu, Susono-shi, Shizuoka Pref. Mitsubishi Aluminum Corporation Technology Development Center (72) Inventor Toshihiro Harada 85-Hiramatsu, Susono-shi Shizuoka Pref.

Claims (9)

[Claims] When producing an aluminum-based alloy plate from an ingot of an aluminum-based alloy, the aluminum-based alloy ingot is successively subjected to a soaking process.
Heating to a homogenization temperature in the range of 520 to 610 ° C. to homogenize. In a hot rolling step, the homogenized aluminum-based alloy ingot is hot-rolled to form a sheet material, and hot rolling is completed. The temperature of the sheet material at that time is adjusted to a temperature range in which the sheet material does not recrystallize within a range of 280 to 350 ° C. In the first cold rolling step, the sheet material after the completion of the hot rolling is reduced to a rolling rate of 60 to 90. %, And in the first intermediate annealing step, the sheet material after the cold rolling is performed at an annealing temperature within a range of 250 to 280 ° C. and an annealing time within a range of 2 to 24 hours. In the second cold rolling step, the sheet material after the first intermediate annealing is cold-rolled so that the rolling ratio is in the range of 5 to 30%. In the second intermediate annealing step, After the two cold-rolled sheets, the annealing temperature is in the range of 270 to 400 ° C. Annealing time is in the range of 2 to 24 hours, and then in the final cold rolling step, the sheet material after the second intermediate annealing is cold-rolled so that the rolling ratio is in the range of 70 to 90%. A method for producing an aluminum-based alloy plate for deep drawing, comprising: 2. The aluminum-based alloy comprises: Si: 0.1 to 0.4% by weight, Fe: 0.3 to 0.6% by weight, Cu: 0.05 to 0.4% by weight, Mn: 2. The composition according to claim 1, wherein the composition contains 0.8 to 1.5% by weight and Mg: 0.8 to 1.5% by weight, with the balance having Al and inevitable impurities. Of producing an aluminum-based alloy sheet for deep drawing of the present invention. 3. The aluminum-based alloy comprises: Si: 0.1 to 0.4% by weight, Fe: 0.3 to 0.6% by weight, Cu: 0.05 to 0.4% by weight, Mn: 0.8 to 1.5 wt% and Mg: 0.8 to 1.5 wt%, Cr: 0.25 wt% or less Zn: 0.05 to 0.25 wt%, Ti: 0 2. An aluminum-based alloy for deep drawing according to claim 1, wherein the alloy contains one or more of the following, and the remainder has a composition consisting of Al and unavoidable impurities. Plate manufacturing method. 4. The deep drawing aluminum base according to claim 1, wherein, in the soaking step, a homogenization heating rate is set to 100 ° C./hour or less and a homogenization time is set to 1 hour or more. Manufacturing method of alloy sheet. 5. The aluminum base alloy sheet for deep drawing according to claim 1, wherein in the hot rolling step, a single-mill reverse hot rough rolling mill of a single mill is used in all steps of the hot rolling. Manufacturing method. 6. The hot-rolling process according to claim 1, wherein the hot-rolling start temperature is 500 ° C. or more and the hot-rolling final pass start temperature is 400 ° C. or more. A method for producing an aluminum-based alloy plate for deep drawing. 7. The method for producing an aluminum-based alloy sheet for deep drawing according to claim 1, wherein in the hot rolling step, a rolling reduction in a final hot rolling pass is set to 50% or more. 8. The method according to claim 1, wherein, in the second cold rolling step, the sheet material after the first intermediate annealing is cold-rolled so that a rolling reduction falls within a range of 10 to 20%.
3. The method for producing an aluminum-based alloy plate for deep drawing according to item 1. 9. The method according to claim 1, wherein in the second intermediate annealing step, the sheet material after the second cold rolling is maintained at an annealing temperature in a range of 270 to 320 ° C. for 1 to 12 hours. A method for producing an aluminum-based alloy sheet for deep drawing according to the above.