JPS63162844A - Production of aluminum alloy plate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to methods of manufacturing Al--Mg--S i alloy plates and articles processed therefrom, as well as products of those methods.

The Al-Mg-Si gold alloy contemplated by the present invention is an alloy having a major content of AA and minor contents of Arashi and Si, and has an Aluminum Association designation of 6
000 series known alloys, such as Aluminum Association (AA) designation 6009.

6010, 6011.6061 and 60630 alloys are examples. The term "plate" is used broadly to mean rolled products without being limited to a particular gauge (thickness) and therefore includes products of plate and foil gauge as well as products of conventional sheet gauge. be.

More specifically, the present invention sequentially includes a solution heat treatment step, a quenching step, a cold working step, and an artificial aging step (in some cases, a natural aging step between the quenching step after the solution heat treatment and the next cold working step). The present invention is directed to a method of manufacturing AA-Mg-8i sheets with a so-called "T8" temper, which is achieved by carrying out a tempering process (with an aging period). Traditionally, T8 tempered AA-Mg-
It is known to provide 8M products (including plates).

In one important specific aspect (which aspect will be discussed in more detail below for purposes of illustrating the invention), the present invention relates to the manufacture of aluminum alloy can bodies and lids, i.e. one-piece drawn, ironed can bodies and The present invention relates to an aluminum alloy sheet for forming a lid for the body thereof, as well as to the forming of can bodies and lids from such alloy sheets and to articles so formed.

Today, metal cans, such as those used for soft drinks, beer, and other beverages, typically have a seamless one-piece body (with a bottom end of the can and a cylindrical side chamber) and a ring-shaped or other opening means. It consists of a swollen top end (lid). The body is formed by a forming process known as pultrusion and ironing, which is commonly used today (e.g. 0.
The process involves drawing the stock into a cup shape, then passing it through a series of dies to form a cup at the bottom end. steps to obtain the desired elongated cylindrical body shape with relatively small sidewall thickness. The top end is made separately from another sheet aluminum alloy material by a separate but conventional forming process and is secured at its circumferential edge to the top edge of the sidewall of the body to form the finished can. give.

The forming operations used in the production of the above-mentioned pultruded, ironed can bodies, in particular the reduction of the thickness of the can side walls (the side walls must nevertheless be able to withstand the internal and external forces applied to it during use) Due to the severity of
In addition, because ordinary molded cans are painted in an operation that requires exposure to 5M with reduced strength, the alloy plate material from which the can bodies are manufactured has special characteristics in terms of strength, formability, and tool abrasion. A combination is required. Important among these properties are ultimate tensile strength, yield strength, elongation and earrings. Achieving the desired combination of properties depends on the composition of the alloy and the processing conditions used to create the material.

Conventionally, the commonly used board for the material of the can body was AA indicated by the Aluminum Association (AA).
3004 alloy from a conventional direct chill cast ingot up to 24 inches thick, the ingot is skinned and homogenized and then sequentially hot and cold rolled to the desired final result. Gauge and often use an annealing treatment between hot rolling and cold rolling operations, where the annealing thickness is about 85 mm cold rolled to the final gauge after annealing.
%), thereby making the can body material H19
(Extremely hard) It has been manufactured by providing it in a tempered state. This method provides the combination of properties currently required in commercial canister materials.

Aluminum alloy with AA designation 5182 is used at the top edge of the lid,
Thus, it has been widely used for the manufacture of lids, and can lids (plates) of such alloys are manufactured in a manner similar to that described above for AA3004 can bodies. The similarities are direct chill casting, homogenization, hot rolling, annealing and cold rolling to H19 temper condition. Cold rolling may be performed between the hot rolling step and the annealing step.

The final can lid material (eg, approximately 0.013 inch gauge) is lacquered and then formed into a lid, the lacquering operation also including a baking (heating) step.

Although the conventional operation described above using different alloys for the can body and lid can yield satisfactory cans, producing cans in which both the body and lid are made from the same alloy makes it difficult for the can to be recycled. This is considered desirable for efficient recovery and reuse of metals. For this purpose, the alloy is required to have both high strength and good formability.

Aluminum alloy sheets with such strength and formability would be equally advantageous for use in a variety of other applications in a variety of gauges.

SUMMARY OF THE INVENTION Broadly speaking, the present invention provides a heat treatable AA'
- a plate of Mg-Si alloy (having a composition as defined below) of intermediate gauge such that the gauge requires rolling from about 25 inches to about 71 inches to achieve the final gauge; preparing a plate; treating the intermediate gauge plate by successive heating and cooling to at least substantially completely solutionize the sludge and Si therein; The board is heated to ambient temperature ζ without
(Allow natural aging by maintaining for at least about 1 day; allow board to reach final gauge (i.e., about 25 to 25 inches)
The final gauge cold-rolled plate is then heated to a predetermined temperature to undergo artificial aging to improve the yield strength. The time is shorter than the time required to obtain the highest yield strength achieved in the final gauge cold rolled plate at the predetermined temperature, and the elongation rate of the plate after artificial aging is within 20 factors of the maximum elongation % value that can be reached by artificial aging of the plate at a predetermined temperature after the same degree of cold rolling carried out after treatment;

It is intended to provide a method of manufacturing an aluminum alloy plate of a predetermined final gauge.

The alloy used in this method is broadly defined as a heat treatable AA-Mg-8i alloy containing a major content of M and a polyfunctional amount of active and effective Si. In the rectangular coordinate graph plotted, the point representing the polyfunctional quantity has the coordinates (0, 2 coefficient Si.

0.4%Mg), (0.2%Si, 0.9chiMg
), (0.4%Si, 1.2%Mg), (1
, 2%Si, 1.2%Mg), and (1,29H
1; i, 0.4% Mg). Alloy compositions in this specification are expressed by weight. Also, as used herein, "effective SiJ" means Si that is not taken up by Fe that is normally present in the alloy.
It is assumed that a proportion of Si equal to % of the Fe content is lost into the electronic compounds (intermetallic compounds). Therefore, under this assumption, the effective Si content (wt%) of a given alloy is:
From the total Si content (wt%) of the alloy to the Fe content (wt%)
) minus the month.

The method of the present invention is similar to the conventionally known method (Al-
It differs from the known method for the production of Mg-8t alloy products in the following points. That is, in an artificial aging process, heating is terminated before the product reaches its maximum yield strength. Specifically, solution heat treated and work hardened A
When A-Mg-8i plate is heated for artificial aging,
Formability (represented by elongation, Chi) as well as yield strength increase initially, but with continued heating the elongation begins to decrease at a point where the yield strength is still increasing. Therefore, stopping and terminating artificial aging before the maximum yield strength is reached will result in a beneficial improvement in strength without substantially impairing formability, and in fact in many cases will result in a substantial improvement in formability. It will be done.

More specifically, the natural aging process after the generalization heat treatment, the subsequent cold rolling process of about 25% to about 71 inches, and the artificial aging process, which involve compliance with special conditions, work cooperatively. This provides an artificially aged plate with excellent strength and forming properties.

In one particular embodiment, the method of the invention comprises forming an artificially aged plate into a can component (i.e., a one-piece drawn, ironed can body having one open end or a lid for closing the open end thereof). It also includes processes. In some cases, baking (heating) is carried out after lacquering the lid material.
Although the operation can be carried out under the conditions selected for the artificial aging process of the present invention, it is currently preferred to artificially age the board before lacquering. It will be appreciated that in such embodiments of the method of the invention, the predetermined final gauge to which the plate is rolled before artificial aging is a desired value, for example the customary gauge for can bodies and lids. . Advantageously, the invention can be embodied in a method of manufacturing a can in which both the lid and the body are made from the same alloy plate made by the above-described process sequence, so that the metal of the can is recycled (as a resource). When it is reused (reused), it can be remelted and reused in the manufacture of new can bodies and lids without extensive alloy composition adjustments.

Broadly speaking, the board products of the present invention can be manufactured in a variety of final gauges. This is because the combination of strength and formability achieved with the present invention is advantageous for a variety of applications. The preferred upper limit for final gauge for product boards of the process of this invention is % inches (1.27 crIL).

Preferably, the alloy composition used in the practice of the present invention contains a slight excess of available S over the stoichiometric amount required to combine in the form of Mg 2 Si with all present.
Preferably, the amount of Mg 2 Si in the alloy is selected to provide a total Mg 2 Si content of about 1.35 to about 1.50%.

Also preferably, the amount of cold rolling between solution heat treatment and artificial aging is at least about 35 inches, and most preferably (for the production of can bodies and lids) the amount of cold rolling is at least about 35 inches. from about 50 to about 71c16, and such conditions include:
given by appropriate selection of intermediate gauges with respect to the desired predetermined final gauge.

The invention also extends to plates and thermal elements manufactured by the method described above and having the advantageous combination of mechanical properties achieved thereby.

Further features and advantages of the invention are further explained by reference to the following description and drawings.

Embodied in a method for producing an Al-Mg-8i alloy plate through successive steps of preparing an intermediate gauge plate from Al-Mg-3i alloy re-rolled material, solution heat treatment, natural aging, cold rolling, and artificial aging. The present invention and the present invention embodied in the products obtained from the method will be described below with reference to the drawings. The characteristics of the alloy used, the production of the rerolled material, the operation of the above steps, and their combination in one method are described below.

Alloy Composition Alloys suitable for the practice of the present invention are broadly defined as Al-IVfg-8i with low content of Si and available Si as described below.
This includes alloys. Its Il/Ig and effective S
The content of i is determined by plotting Mg% against effective Si% in a rectangular coordinate graph (see Figure 1), and the point representing the selection and effective Si content of the alloy is pentagon 10 in Figure In the area of , i.e., the coordinates (0,2% Si, 0.4 direction), (0,2% Si, 0.9% F problem).

(0.4%Si, 1. 0 happy), (1.2%Si, 1.
2% Mg) and (1,2% Si, 0.4% Mg
) is within the pentagonal area defined by . Preferred alloy compositions within this broad definition are those in which the point representing the available Si content lies inside the pentagon and to the right of line 12 (which line 12 is theoretically Mg
2 S i weight ratio, i.e. Mg/S i = 1.7
3/1). Preferably, the alloy also has an amount defined by the pentagon 10 ((6) and the effective S
Cu containing i as an essential component, optionally up to 0.9 yen,
Fe up to 1.0%, Mn up to 0.8%, -0.3
Cr up to 5%.

Contains up to 0.25% Zn, up to 0.20% Ti,
The remainder consists primarily of M at a normal impurity concentration that does not substantially adversely affect the combination of strength and formability associated with this invention.

Specific examples of known alloys that fall within the broad definition above and are suitable for the practice of the present invention include Aluminum Association designations AA6009.6010°6011.6061
and 6063, and their registered compositions are as shown in the table below.

Alloys in the composition range of AA6061 above are particularly preferred,
Preferred for embodiments of the present invention for making pultruded and ironed cans and lids, and most preferred today for such embodiments, are 0.25% Fe, 0.5Q%
Cu, 0.35%Si, 0.05% (maximum) M
n +0.901Mg, 0.05 factor (maximum) Zn,
0.17%Cr.

0.25% (max) Ti, others 0.10% (max).

It is an alloy with a nominal composition of balance aluminum.

Here, "(maximum)" means that the numerical value attached with it is the maximum, and the element so indicated is not just an arbitrary component or can be tolerated as an impurity up to its maximum value. It means something. For good age hardening response, the alloy should have a Mg/Si weight ratio of 1.
It should contain more available Si (at least about 0.051 more) than is needed to stoichiometrically form Mg 2 Si, which is 76/1, and as discussed above. When making this calculation, it is common to assume that a proportion of the total Si content equal to % of the Fe content is lost as electronic compounds (intermetallic compounds). Also,
AA6061 alloy has a total Mg of about 1.35 to about 1.50
It is also common to have a 2 Si content.

Another example of an alloy suitable for can material is that in the graph of FIG.
,3%Si, 0.8%Mg), (0,55%Si.

1.2% Mg), (1,05 polyS1.1.2 blood draw →, (
0.8%Si, 0.81Mg) and the effective Si
It is an alloy containing This parallelogram is represented in FIG. 1 by the dashed line 14 and the top horizontal line portion of the pentagon 100. The preferred alloy composition within this parallelogram range is Ivfg and the point indicating the effective Si content is the line 12 above.
It is on the right side of . Among these alloy compositions, the most preferable one is one that falls above and to the left of the broken line ]6 and up to [Iwa]2, that is, the coordinates (0,7%Si, 0
．． 9), '0.875%Si+1-2%Mg), (
cJ, 69%Si, 1.2%iQ1g).

It falls within the quadrilateral (c) defined by (0.52%Si, 0.91Mg).

Re-rolling (re-rolling) The starting material for carrying out the exemplary embodiment of the invention has a composition as defined above and is of a suitable gauge for the initial cold rolling step of the process of the invention. It is an alloy body in the form of a whelk. Such strips are referred to herein as "reroll material." Typically, beam rolled stock is made by casting the alloy into plate-shaped ingots of conventional dimensions (e.g., by so-called direct chill casting), stripping, homogenizing, and hot rolling to reroll gauge. . All of this is accomplished by well-known and quite conventional operations. Alternatively, re-rolled material may be cast from a continuous strip casting trap, i.e. between a cooled endless moving steel belt, between chilled rolls, or between the cooled walls of a stationary mold. It can be manufactured by continuously casting the alloy into relatively thin strips in a cavity (these means are also well known in the art). Such continuously hammered strips can be cast thin enough to allow direct cold rolling, or can be hot rolled to a roll gauge.

However, the resulting rerolled material is cooled and usually wound into a coil. Therefore, in at least most cases it is preferred that the roll gauge be thin enough to allow direct coil winding.

Preparation of Intermediate Gauge Plate In certain exemplary embodiments of the present invention, the rerolled stock made as described above is cold rolled (using operations quite conventional for cold rolling of Al-Mg-Si alloys). Roll and reduce to medium gauge strip to be solution heat treated. This intermediate gauge, i.e., solution heat treated gauge, takes into account the predetermined desired final gauge of the plate to be manufactured, and requires a reduction of about 25φ to about 71% from that intermediate gauge to achieve the final gauge. Selected as required. That is, the intermediate gauge is about 25 to about 71 by cold rolling after solution heat treatment as described above.
% cold reduction is further provided. Preferably, the amount of cold reduction after solution heat treatment is about 35φ~
about 71%, and most preferably (particularly for the manufacture of can bodies and can lids) about 50 to about 71 inches;
For such a preferred implementation, an intermediate gauge is therefore selected accordingly. The reason why an intermediate gauge is selected to provide a specific lid cold reduction after solution heat treatment is to enable desired properties to be developed in the strip by cold working after solution heat treatment. The selection of a particular intermediate gauge within the above ranges will depend on the particular properties desired to be obtained in the final product.

Although the reroll gauge is not critical, it will be appreciated that by selecting it suitably larger than the intermediate gauge mentioned above, a considerable reduction in temperature can be achieved in the initial cold rolling process. . Merely for purposes of illustration, in one example of producing a 0.013 inch final gauge can lid by the method of the present invention, the intermediate gauge (solution heat treated gauge) is 0.026 to 0.045 inch. The cold reduction to final gauge after solution heat treatment is selected to be between 50 and about 71 inches, depending on the particular final properties desired. The reroll gauge in this example is conveniently between about 0.120 and about 0.160.
Inches.

In a broader aspect, it is understood that although the present invention does not require that the plate be cold rolled to medium gauge, it is within the scope of the invention to prepare medium gauge plate by other methods. It will be. For example, in some cases it is also possible to obtain intermediate gauge directly by hot rolling without any cold rolling prior to solution heat treatment.

Solution Heat Treatment The intermediate gauge initially cold rolled strip described above is solution heat treated (by heating and quenching) under conditions selected to effect substantially complete solutionization of the knee and Si therein. be done. The steps and conditions used here may also be quite customary and are therefore well known per se to the person skilled in the art. A batch donor heat treatment can be used, but the time/temperature conditions will depend on the degree of roughness of the N1g2Si phase. 560 strips
A batch method of heating for 1 hour at 0.degree. C. is quite satisfactory. Alternatively, and preferably, continuous solution heat treatment of intermediate gauge strips (e.g. carried out in a continuous annealing line) can be employed, which involves short soaking times and therefore temperature is required. For example, in continuous solution heat treatment, a maximum (peak) metal temperature of 570° C. has been found to be suitable using very short soaking times of 1 minute or less.

To keep the falls and Si in the solution state, the metal must be rapidly cooled (quenched) from the solution heat treatment temperature to room temperature. That is, it must be rapidly cooled within 60 seconds, preferably within 60 seconds. If the intermediate gauges are small enough, air quenching can be used, but for larger gauges water quenching is necessary, and water quenching is suitable for all gauges.

The as-quenched intermediate gauge IJ tube is preferably heated at ambient temperature (e.g., about 0°C to 40°C) for at least about 1 day without any intermediate subsequent heat treatment after solution heat treatment and quenching. is allowed to age naturally by leaving it for at least about 6 days.

Natural aging times of greater than 6 days (regardless of their length) can also be used. The reason for carrying out such a natural aging step in the method of the present invention is that the strength of the strip is Mg 2
This is to obtain a relatively stable state due to the formation of lattice-coherent nuclei of the Si phase.

Cold Rolling to Final Gauge After natural aging, and again without any intermediate heat treatment, the strip is cold rolled and work hardened while reducing it to a predetermined final gauge. The degree of cold reduction in this cold rolling process according to the present invention is about 25
to about 71%, preferably at least 35%, and as already mentioned most preferably (particularly for the manufacture of can bodies and lids) about 50% to about 71%, with intermediate gauges of: It is selected to provide the above cold reduction degree after solution heat treatment and natural aging. As before, the equipment and operations used to carry out cold reduction may be all (conventional) for cold rolling of aluminum alloy strips.This cold rolling operation after solution heat treatment According to
Work hardening increases the strength and produces a final gauge strip or plate without any heat treatment after quenching of the solution heat treatment. Typical or exemplary final gauges are 0.013 inches for can lids, 0.014 inches for can bodies, or even larger gauges (e.g., 0.040 inches) for other finished products. ).

This cold rolling process to the final gauge and the next artificial aging process (
(discussed below), there is also some natural statute of limitations that can hardly be avoided. This is because, in the course of normal commercial operations, cold rolled strip is not artificially aged in parts but is exposed to ambient temperatures for some period of time. Such incidental natural aging, however long it may be, is not a problem for the method of the present invention.

Artificial Aging Further according to the invention, and as a feature of the invention, the as-rolled strip at final gauge (usually having undergone some concomitant natural aging as described above) , subjected to artificial aging by heating at a predetermined elevated temperature to increase the yield strength. The time of this artificial aging is shorter than that required to obtain the highest yield strength achieved by heating the same strip to a predetermined temperature, and the elongation of the IJ tube after artificial aging is The modulus is within 20 modulus of the highest elongation modulus obtained by heating the same strip to the same temperature. Here, the expression "heating to (temperature)" includes both (i) raising the IJ tube to a predetermined temperature and maintaining it at that temperature.

In this context, AA artificially aged from a T3 tempered state
The yield strength and elongation of -Mg-8i strips depend on, for a given elevated temperature during the artificial aging process, the time of heating to that temperature. More specifically, during such heating, the elongation % (one measure of formability) as well as the yield strength first increase to a maximum value and then start to decrease, but the maximum elongation % is faster than the maximum yield strength. We have discovered that this can be achieved in stages. Therefore, by the process of the present invention in which the strip is artificially aged by heating to elevated temperatures for a time shorter than that required to achieve the maximum yield strength (as opposed to the maximum yield strength achieved in prior practice). (T
This provides the benefit of increasing the yield strength (compared to the yield strength in the T3 temper condition) without unduly compromising the elongation strength (compared to the yield strength in the T3 temper condition). A sufficiently adequate increase in strength for purposes such as drawing and ironing can manufacturing is achieved by increasing the elongation to within 20 factors of the highest value obtainable when the same strip is artificially aged at the same temperature. This can be achieved by artificial aging for a period of time.

In fact, in many cases preferably the artificial aging time is T6
The elongation can be selected so as to result in a substantial increase in the elongation, as well as a satisfactory improvement in the yield strength, compared to the elongation of the strip in the tempered state, ie just before artificial aging. Other relevant mechanical properties were also found to be at a suitable level (e.g. suitable for canning and other uses) in the T8 strip after such an artificial aging period.

The relationships between aging time and yield strength and elongation factors are shown in Figures 2-4 for exemplary treatments. These figures show 0.2% Cu, 0.26% Fe.

0.89%Mg, 0.04%, 0.64%Si, 0.
AA60.027 Ti, 0.2096 Cr, and the balance mainly consists of aluminum. lS1 alloy
It shows various properties obtained by artificial aging of IJ whelks.

This strip is made directly from chill cast ingots,
It was homogenized, hot rolled and coiled on a 0.13 inch glue roll gauge, hot rolled to a medium gauge of 0.046 inch, and solution annealed on a continuous annealing line (60 seconds; 570°C). Heat treated.

The strip is then allowed to age at ambient temperature for at least 1 hour and is either 0.030 inch (strip sample in Figure 2) or 0.0135 inch (strip sample in Figures 6 and 4).
The IJ tube sample) was hot rolled to the final gauge. This 0. ．． Several samples of 0.030-inch final gauge strip were artificially aged at 160°C (30° C.) for various times, and several samples of 0.0135-inch final gauge strip were artificially aged at 160° C. ) or 185'C (Figure 4) for various times.The curves in Figures 2 to 4 show the characteristics of each sample in the T8 tempered state after various artificial aging times. Aging time is zero (at the time of rolling)
The values of the various properties shown are the values measured for each sample in the T6 tempered state before artificial aging. For all aging times, the strength measured in the machine direction (41 machine direction) is generally greater than the measurements in the transverse direction, but exhibits substantially the same time-dependent properties. These and other property characteristics of the samples of Figures 2-4 are shown in Table I.

It can be seen that for each of the samples shown in Figures 2-4, the yield strength and elongation coefficient increase early during artificial aging (compared to the values in the T3 temper condition).

As the aging (heating) treatment continues, the elongation begins to decrease, but the yield strength continues to increase for some additional time before beginning to decrease. In each case, a time point can be selected for which the elongation is within 20% of its maximum value and the yield strength is greater than that of the T6 tempered state; varies depending on factors such as artificial aging temperature and cold opening pressure reduction after solution heat treatment (35% in Figure 2, 71% in Figures 3 and 4).

As a specific example, 0.01 of AA6061 alloy work hardened by 71 inches of cold reduction after solution treatment.
For 3-inch gauge strip, aging times of 160° C. (or even shorter times at higher temperatures) result in significant increases in both elongation and yield strength, while concomitantly increasing Erichsen cup height and ultimate Satisfactory levels of other properties such as tensile strength can be obtained. More generally, the time to maximum elongation and the time to maximum yield strength during artificial aging depend on the alloy composition; the efficiency of the solution heat treatment depends on the time, temperature, quench rate and previous Homogenization of the ingot at the stage (e.g. homogenization process removes all coarse 'Mg2
Factors such as whether S i is melted or not), the cold rolling reduction rate after solution heat treatment, the degree of natural aging, and whether natural aging is performed before or after cold rolling after solution heat treatment. influenced by. The double blade and final gauge value mentioned above affect the magnitude of the maximum elongation rate Chi during artificial aging. Therefore, in the practice of the present invention, the appropriate heating time for the artificial aging process is determined by aging a series of samples for various times while keeping all these factors constant after selecting the above-mentioned double blades. It is determined by determining the artificial aging time dependent characteristics of yield strength and elongation coefficient.

The aging time at which suitable values of yield strength and elongation Q are achieved can thus be readily determined and taken as the artificial aging time for commercial production of the same strip material. The operation for determining the time-dependent characteristics in this manner is simple and can be easily performed by those skilled in the art.

The artificial aging step of the method of the invention is performed in batches by heating a coil of final gauge (and initially in T6 tempered) strip to a temperature in the appropriate range (e.g. 160'C) for 1 to 3 hours. It can be carried out as an artificial aging treatment. Alternatively, by heating the T3 strip at a significantly elevated temperature and for a short period of time (e.g. about 20
Aging can be performed by heating for about 10 to about 20 minutes at 0°C. In particular examples, such heating steps can also be used for certain other functions;
For example, in the manufacture of end caps, the baking of the cap material after lacquer coating can be carried out under the above conditions so that the artificial aging step of the present invention can be carried out simultaneously. In this rapid baking (heating) treatment, the artificial aging step also results in an increase in yield strength, which allows the artificially aged strip to elongate within 20% of the highest value that can be achieved during baking for a given time. give to Such an elongation value is usually and preferably greater than the elongation of the IJ tube in the T3 tempered state before baking.

After completion of the artificial aging process, the product of the method of the present invention is AA! in T8 tempered condition. - a plate of Mg-8i alloy, by the above-mentioned series of steps (in particular an artificial aging process carried out under specific conditions of aging for a time shorter than that required to achieve the maximum yield strength). It combines high strength and good formability. Such product sheets can be manufactured to have a variety of final gauges for a wide variety of end uses where such a combination of strength and formability is required or advantageous.

In a particular and presently preferred embodiment of the method of the invention used for the manufacture of can components (i.e. drawn, evening can bodies or lids therefor), the results obtained in carrying out the steps described above are The final gauge of the T6 strip is selected to be suitable for direct molding of can bodies or lids (e.g., 0.014 inch final gauge for the former and 0.013 inch final gauge for the latter); And after artificial aging treatment, T3)
The step of forming the IJ tube into a one-piece can body or end cap is carried out using a molding operation commonly used for forming such can bodies and lids. Typically, the method in each case (body or lid) includes a lacquering step followed by a baking step.

In the case of lids, it is customary to lacquer and bake the plate of material before the lid forming operation. The lacquer in such cases can be applied when the board is in the T3 temper condition, and the subsequent baking of the lacquered board, as described above, is carried out to carry out the special artificial aging treatment of the present invention. under selected conditions (e.g. at about 200°C)
(heating for 20 minutes). The lacquered and baked (T8 tempered) board is then conventionally formed into an end cap.Alternatively, the T6 tempered board is first artificially aged according to the invention, then lacquered, baked, and capped. It can also be shaped into

In the case of the can body material, forming (pultrusion and ironing) operations are performed prior to lacquering and baking, and the final gauge material is subjected to the artificial aging process of the present invention prior to forming into the can body. Baking after lacquering is thus a separate heat treatment carried out after artificial aging. If baking after lacquering is carried out as a separate treatment, there is usually some reduction in strength, but a relatively smaller strength reduction than that caused by baking of AA3004 paint occurs.

The products of these embodiments of the process of the invention are drawn and ironed can bodies and end caps of Al-Mg-Si alloys each having advantageous properties developed by the above treatment combinations. be. Most advantageously, a lid and body of the same alloy composition are made and assembled to create a can in which both parts (lid and body) are of the desired single composition, and metal recycling ) and facilitate reuse.

The invention likewise provides further important advantages for the manufacture of endcaps and bodies. As shown in Table 1, AA606 produced by method 1 of the present invention has these advantages.
This will become clear by comparing the can materials of 1 can with conventional AA 3004 and AA5182 can bodies and lid bodies. In this table ■, AA6061 material (0,
013 inch gauge) is representative of the product of the present invention.

606'l T4 Natural aging 1 week 3
56061 T3 50chi cold working 51
6061 T8 lacquer painting 55
3004) (19 as rolled 42ro0
04 HI3 Lacquer painting 6751
82 HI3 As rolled 6051
82 HI3 lacquer painting 541B
24
-9 2.5-3.5 0.
190 i, o-1, 55182, 5-3, 50,
1901,0-1,5393,02,5-3,50,1
952,0-3,0344,5 5B 3. 448,50,1751,0-1,5 The AA606i material shown as a representative example in the table above is made by directly chill casting and homogenizing the ingot, hot rolling, cold rolling to intermediate gauge, and solution treatment. It was produced by a continuous process of heat treatment and quenching, natural aging for at least one day, cold rolling to final gauge at a reduction of 50-71%, and artificial aging at 160° C. for 3 hours as described above. The lacquering treatment (in the case of AA-6061 material) is shown in the table next to artificial aging and in each case involved baking the painted board at 195° C. for 10 minutes.

As is clear from the above table, AA made according to the present invention
The 6061-T8 material is coated with conventional AA30 before lacquering.
It has earrings and Erichsen values equivalent to U4 body material, and has better flexibility and higher (14 ksi) yield strength than AA3004 body material (ksi=
kilobond/square inch). After lacquering, the yield strength decreases in both cases, but the difference in yield strength is still large due to the effect of AA6061-T8 material (1
7 ksi difference).

The strength after this lacquering is especially important for the end body. This is because the yield strength directly affects the pressure value at which the bottom of the filled can will buckle outward1.
A minimum bottom buckling pressure of 90 psi is normally required for drawn and ironed canister bodies for post-fill sterilization operations. 3004-H19 can body is generally 95-110p
si buckling pressure is generated. In one test, 6
The 061-T8 can body was found to generate bottom seat hydraulic pressure in excess of 130 psi. Therefore, the 6061-T8 body material produced by the method of the present invention is 3004-T8.
Its gauge can be reduced compared to HI3 material, resulting in lower metal cost per can while still fully meeting buckling pressure requirements.

Compared to 5182-H19 can lid material, the lacquered 6061-T8 material produced according to the present invention has a higher yield strength (7 ksi higher in the example in the table), a higher Erichsen Kup value and the same flexibility, but 6061-T8 material may exhibit slightly lower formability than 5182-Hl 9 material under severe pultrusion and pouring, and therefore 6061-T8
The higher yield strength of does not provide improved buckling pressure performance. The reason for this is the higher work hardening rate of the 5182 alloy, which provides strength comparable to 6061 in the formed areas of the lid that really determine buckling performance.

Nevertheless, as shown by the comparison of properties in the table, in general the properties of 6061-T 8 plate are sufficiently suitable for use as both a lid and a body;
and properties equal to or better than those of conventional alloys used separately for the lid and body.

It will be understood that the invention is not limited to the specific features and embodiments described above, but may be embodied in other ways without departing from its spirit.

[Brief explanation of the drawing]

FIG. 1 is a rectangular plot of % Mg versus % available Si showing the available and available Si contents of alloys suitable for the practice of the present invention. Figure 2 is a rectangular coordinate graph in which the ultimate tensile strength (UTS), yield strength (YS), elongation coefficient and Erichsen cup depth of an artificially aged (T8 tempered) AA6061 alloy plate are plotted against the artificial aging time. After solution heat treatment, this alloy plate was cold rolled for 35 rounds to a final gauge of 0.030 inch, and then artificially aged at 160°C. Figure 3 shows 0.01 after solution heat treatment and 71% cold rolling.
2 is a graph similar to FIG. 2 for an AA6061 (T8) alloy plate made to a 35 inch final gauge and then artificially aged at 160°C. Figure 4 shows a 71% cold rolling process after solution heat treatment.
FIG. 3 is a graph similar to FIGS. 2 and 3 for an AA6061 (T8) alloy plate made to a final gauge of 0.135 inches and then artificially aged at 185°C. Book 2, machine number CK, 5.1. ) ``9F'-g!5 Effective time (deceased) Milk 4 Closed Slightly (x, s, z,) 9 Statute of limitations (11) Procedural amendment □ January 1988 r Commissioner of the Patent Office Kuni Ogawa Husband 2, Title of invention: Process for manufacturing aluminum alloy plates 3, Relationship to the case of the person making the amendment Applicant Address: Alcan International Inc. Limited 4, Agent address: 2-2-1 Otemachi, Chiyoda-ku, Tokyo No. Shin-Otemachi Building, Room 206, 5, Date of amendment order: November 24, 1988 (Transportation date) 6, Subject of amendment

Claims (16)

[Claims] (1) When manufacturing an aluminum alloy plate of a predetermined final gauge, (a) main content of Al, small content of Mg and effective Si
In a rectangular coordinate graph in which the Mg percentage of a heat-treatable Al-Mg-Si alloy containing
, 0.4%Mg), (0.2%Si, 0.9%Mg),
(0.4%Si, 1.2%Mg), (1.2%Si, 1
．． 2% Mg) and (1.2% Si, 0.4% Mg), the gauge of which is within the pentagonal area defined by providing a plate of intermediate gauge, such as requiring rolling of about 25% to about 71% to achieve the final gauge; (b) to at least substantially completely solutionize the Mg and Si therein; (c) solution heat treating the intermediate gauge plate by successive heating and quenching to give a solution heat treatment; (c) after quenching and without intermediate heat treatment, the plate is subjected to a (d) after natural aging and without intermediate heat treatment, the plate is cold rolled to final gauge; and (e) the cold rolled plate of final gauge is brought to a predetermined temperature. Artificial aging is performed to improve the yield strength by heating the final gauge cold rolled plate to the maximum yield strength that can be reached by artificial aging at the predetermined temperature. the final gauge cold rolled plate at the predetermined temperature after the cold rolling carried out in step (d). A method for manufacturing an aluminum alloy plate of a predetermined final gauge, which comprises each step, such that the elongation rate is within 20% of the maximum elongation % value that can be reached by artificial aging. 2. The method of claim 1, wherein the effective Si content of the alloy is in excess of the amount required to fully combine with the Mg component and exist in the form of Mg_2Si. (3) Claims in which the effective Si content is greater by an amount of at least 0.05% of the weight of the alloy than is required for such complete bonding with the Mg content of the alloy. The method described in Section 2. (4) the alloy contains Fe, and the Si content is present in the alloy at least 0.05% by weight of the alloy, less than the amount required to fully combine with the Mg content of the alloy; 4. The method of claim 3, wherein the weight percent of Fe is greater than the sum of at least about 1/3 of the weight percent of Fe. (5) The Mg content of the alloy is about 1.35% to about 1.50%
5. The method of claim 4, wherein the method is selected to give a total MgSi content of . 6. The method of claim 1, wherein the natural aging step is carried out by holding the plate at ambient temperature for at least about 3 days. 7. The method of claim 1, wherein the intermediate gauge value is such that at least about 35% of the rolling is required from that value to obtain the final gauge. 8. The method of claim 7, wherein the intermediate gauge value is such that at least about 50% of the rolling is required from that value to obtain the final gauge. (9) A patent in which the artificial aging process is carried out by heating the plate to a predetermined temperature for a certain period of time so that the percent elongation of the plate is greater than the percent elongation of the plate immediately before the artificial aging process. A method according to claim 1. (10) An aluminum alloy plate produced by the method set forth in claim 1. (11) further comprising the step of forming the plate into a part of the can,
The can consists of a one-piece drawn and ironed main body having an open end, and a lid for closing the open end, and the main body and the lid are each a member of the can. The method described in Section 1. (12) The part to be formed is a can lid; the plate is lacquered after rolling to final gauge and baked under conditions selected to effect artificial aging of the plate as described above; 12. The method according to claim 11, wherein the step of forming the plate is carried out after baking. (13) The method according to claim 11, wherein the member is a one-piece drawn and ironed can body, and the step of forming the plate onto the body is carried out after the artificial aging step. (14) A can member manufactured by the method according to claim 11. (15) The alloy contains about 0.2 to about 1.2% effective Si, about 0.4 to about 1.2% Mg, up to 0.9% Cu, 1.
Fe up to 0%, Mn up to 0.8%, Cr up to 0.35%, Zn up to 0.25%, Ti up to 0.20%
, the remainder Al. (16) A method for manufacturing an aluminum alloy can mainly consisting of a one-piece drawn and ironed main body having an open end and a lid for closing the open end, the method comprising: (a) heat-treatable Al-Mg-Si; (b) a second plate of the same Al-Mg-Si alloy, T3 tempered;
(c) Artificial aging is performed to improve the yield strength of each plate by heating it to a predetermined temperature, and the temperature at that time is the same as that of the plate at the predetermined temperature. less than the time required to achieve the highest yield strength achievable by artificial aging of the plate, and the percent elongation of the plate after artificial aging is less than that achieved by artificial aging of the same plate at the specified temperature. (d) one plate is formed into a one-piece pultruded ironed can body having an open end; (e) the other plate is formed into a one-piece pultruded ironed can body having an open end; The above method for producing a can, comprising the steps of forming into a lid, and (f) assembling the main body and lid to make a closed can.