GB2172303A - Aluminium alloy sheet - Google Patents

Aluminium alloy sheet Download PDF

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Publication number
GB2172303A
GB2172303A GB8519274A GB8519274A GB2172303A GB 2172303 A GB2172303 A GB 2172303A GB 8519274 A GB8519274 A GB 8519274A GB 8519274 A GB8519274 A GB 8519274A GB 2172303 A GB2172303 A GB 2172303A
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Prior art keywords
alloy
cold
temperature
earing
roll
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GB8519274D0 (en )
GB2172303B (en )
Inventor
Harish D Merchant
James G Morris
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Continental Group Inc
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Continental Group Inc
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    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22FCHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/04Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon

Description

1

GB 2 172 303A 1

SPECIFICATION Aluminium alloy sheet

5 The present invention is directed to a process for preparing continuous strip cast aluminium alloy suitable for use in the manufacture of deep drawn and wall-ironed articles such as cans and the like.

In recent years, aluminium alloys such as the Aluminium Association specification 3004 have been successfully fabricated into two piece beverage cans by deep drawing and ironing. The 10 expanding use of two piece aluminum cans has created a need for aluminium alloy sheet for forming the can body that not only possesses the required combination of formability and strength properties but is also economical to manufacture.

Typically the aluminium alloy sheet useful in the production of deep drawn and ironed beverage cans is cast by direct chill casting an ingot having a thickness of about 20-25 inches. The 15 ingot is homogenized at 950-1125°F for 4-24 hours and then subjected to hot rolling wherein the ingot is passed through a series of breakdown rolls maintained at a temperature of 400-900°F to reduce the ingot in thickness to a reroll gauge of about 0.0130 inch.

Thereafter, the reroll stock is subjected to an annealing step wherein the stock is heated at 600-900°F for 0.5-3 hours to effect recrystallisation of the metal structure. The annealed reroll 20 stock is subjected to a final work hardening step wherein the reroll stock is cold rolled (room temperature rolling) to a final gauge of about 0.013 inch or about 90% of its original thickness to produce the substantially full hard (H19) temper required for two-piece can body stock.

In spite of the successful use in can-making of direct chill ingot cast aluminium alloy, economic and energy considerations would favor the manufacture of the aluminum sheet by continuous 25 strip casting. In this process the molten aluminum is cast and solidified into a thin web of one inch or less in thickness so that subsequent rolling is reduced to a minimum and the costly step of hot rolling is eliminated.

In the manufacture of continuous strip cast aluminum alloy for can manufacture, the thin, e.g. 0.2-1.0 inch solidified cast web is typically reduced in thickness to a gauge of about 0.130 inch 30 by cold rolling with an intermediate recrystallization anneal at about 600-900°F. Thereafter, as in the manufacture of direct chill ingot cast stock, the thinned, annealed stock is subjected to a final work hardening step by cold rolling to a final gauge of about 0.013 inch to produce the H19 temper required for can body manufacture.

Although the continuous strip cast aluminum alloy is advantageously utilized for many fabri-35 cated products, such stock has not been used extensively for the manufacture of drawn and wall-ironed can bodies.

In the production of two-piece drawn and wall-ironed beverage cans, circular discs or blanks are cut or punched from the cold worked (H19) sheet for deep drawing into the desired shape. Deep drawing is a process for forming sheet metal between punch and die to produce a cup or 40 shell-like part. When a deep drawn shell with a heavy bottom and thin sidewalls is desired, wall-ironing is used in conjunction with deep drawing. The blank is first drawn to approximately the final step diameter cup. The sidewalls are then reduced in thickness in one or more ironing operations.

Because of the nature of the working stresses incurred during wall-ironing of the deep drawn 45 shell, when continuous strip cast aluminium alloy such as 3004 is subjected to wall-ironing, scoring may occur on the die surface; alternately, deep grooves may appear on the finished can which is referred to in the art as "galling". Galling adversely affects the acceptaility of the can product and the effectiveness of the can manufacturing process. Galling is not normally observed during wall-ironing aluminum sheets of the same alloy composition produced from direct chill 50 ingot casting.

In spite of the economic advantage of the strip casting process, due to the drawback of not being gall-free when subjected to severe mechanical operations such as wall-ironing operations in two-piece aluminum can making, the utility and applicability of continuous strip cast aluminum alloy for can making has been extremely limited.

55 The art has addressed the problem of providing continuous strip cast aluminum alloys which have the capability to be gall-free when subjected to the severe mechanical working conditiions of can making. For example, U. S. 4,111,721 discloses a process for imparting an anti-galling character to continuous strip cast aluminum alloy wherein the aluminum strip is heat treated at a temperature of at least 900°F and advantageously at about 1150°F for a period of time between 60 about 16 to 24 hours prior to its final cold reduction pass.

The art prior to U. S. 4,111,721, namely U. S. 3,930,895 disclosed that in the process of making continuous strip cast aluminum alloy suitable for can making, the cast strip, before cold rolling is homogenized at a temperature of about 950 to 1050°F for about 8 to about 16 hours.

Although the art reported that gall-free continuous strip cast aluminum alloy had been pro-65 duced, the strip has remained substantially unacceptable for can making stock because of the

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GB 2 172 303A 2

problem of "earing" which manifests itself as a scalloped appearance around the top edge of the cup during the deep drawing cup formation step of the drawn and wall-iron processing of the aluminum sheet.

The scallops, or ears, represent an almost universally undesirable feature of the cup as the 5 ears must be removed in order to present a smooth or flat upper lip on the cup. This of course necessitates cup trimming prior or subsequent to wall-ironing, with an attendant increase in production costs and material waste.

The level of earing in a drawn cup is determined by the following equation:

10 he-ht

X100=% Earing

(he+ht)/2

where he is the distance between the bottom of the cup and the peak of the ear and ht is the 15 distance between the bottom of the cup and the valley of the ear.

To be acceptable for can making, the aluminum alloy sheet when processed into a cup must exhibit a level of earing of no more than about 3.5% and preferably less than about 3% earing. The level of earing experienced with commercially available continuously cast strip of 3004 aluminum alloy is generally in the range of 5% or more.

20 It is evident, therefore, that the reduction of the degree of earing during deep drawing of continuous cast aluminium strip to a level of about 3.5% or less represents a major contribution to the art of manufacture of continuous cast aluminum strip can stock.

Another problem encountered with continuous strip cast aluminum alloy 3004 is that the alloy sheet when fabricated into a two piece drawn and wall-ironed can exhibits a marginal level of 25 buckle strength, that is, the ability of the can to withstand high internal pressure without bottom inversion.

Buckle strength is determined by applying pressure within a drawn and wall-ironed can and then gradually increasing the pressure until the bottom end of the can deforms and bulges out, i.e., it buckles. The pressure at which the bottom buckles is then designated as the buckle 30 strength. To be acceptable as can body stock a can formed from the alloy sheet must exhibit a buckle strength of at least 90 pounds per square inch (psi), and preferably between 95 and 100 psi. Cans drawn and wall ironed from a hard temper sheet of the continuous strip cast aluminum alloy 3004 homogenized at 1050-1100° to eliminate galling exhibit a buckle strength of about 85 psi.

35 The present invention is directed to a process for the preparation of non-galling, low earing can stock from continuously cast aluminum strip suitable for deep drawing and wall-ironing into hollow articles wherein the molten aluminum material is cast by continuous strip casting into a web generally of an inch or less in thickness. The strip material is heated to a temperature of from 950 to 1150°F for a time sufficient to homogenize the alloy. The homogenized strip 40 material is cold rolled to effect a first reduction in sheet thickness of at least 25%. The cold rolled sheet is heated to a recovery temperature of up to about 550°F, and subjected to a second cold rolling to effect a reduction in thickness of at least 10%. The cold rolled sheet product is heated to effect recrystallization of the grain structure and then subjected to effect a final reduction in thickness of at least 75% of the original thickness of the sheet to impart an 45 H19 temper to the sheet.

To effect the most advantageous reduction-in earing, the sheet is subjected to a second recovery heating of up to 550°F intermediate between the second cold reduction and the recrystallization heating step.

As will hereinafter be illustrated, it has been determined that in the fabrication of strip cast 50 aluminum sheet suitable for the production of drawn and wall-ironed beverage containers, control of the homogenization step within the parameters set forth above will render the sheet resistant to galling when subjected to drawing and ironing operations. Control of the cold roll and recovery heating parameters set forth above prior to the recrysallization heating step, will result in the fabrication of an aluminum sheet exhibiting low earing properties as well as non-galling 55 characteristics.

Generally in affecting homogenization to prepare an aluminum alloy sheet product in accordance with the present invention, the continuous cast web is heated at about 950 to about 1150°F and preferably about 1000 to about 1100°F for a period of time up to about 50 hours and preferably about 10 to about 25 hours. Advantageously, the homogenization treatment is 60 conducted at a temperature of about 1100°F for at least about 10 hours. It is recognized that several hours are required to heat the metal to reach the temperature at which homogenization is effected.

In the event that the cast aluminum web is subjected to homogenization temperatures while in coil form, it has been determined that the coil be heated in a slow, pre-programmed manner for 65 time periods ranging from 2 to 10 hours at increasing temperatures to avoid incipient melting of

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GB 2 172 303A 3

the alloy which will otherwise cause the coil layers to fuse and weld together and render the coiled product unsuitable for subsequent use. A programmed heating sequence which has been found advantageous for the homogenization of the continuous cast aluminum coil is as follows:

Temperature of the web is raised from ambient (75°F) to 1000°F over a 5 hour period.

5 Temperature of the web is raised from 1000 to 1050°F over a 3 hour period. 5

Temperature of the web is raised from 1050 to 1100°F over a 5 hour period.

Web is homogenized at 1100±10°F for 20 hours.

The homogenization step of the process of the present invention imparts a very critical change in the microstructure of the alloy primarily in the size, shape and distribution of the intermetallic 10 particles present in the alloy matrix. It has been determined that the change in intermetallic 10

particle disposition is dependent upon the temperature as well as the time of the homogenization treatment and that the degree of galling is inversely dependent upon the intermetallic particle size.

Examination of photomicrographs of 3004 aluminum alloy subjected to the homogenization 15 sequence of the present invention indicates that the secondary constituents in the aluminum 15

alloy, e.g. (MnFeSi) Al, are caused to agglomerate whereby they change their shape substantially and increase in size. The net effect of this is the development of intermetallic particles approaching a globular shape having a particle size of 1 to 3 microns. These relatively large, globular shaped particles are believed to act as galling-resistant bearings for the strip cast stock during 20 the severe mechanical working encountered in the wall-ironing operations of two piece can 20

manufacture.

For example, continuous cast 3004 aluminum alloy strip cold rolled and size-reduced to 0.0135 inch gauge to H-19 temper by conventional practice typically has an intermetallic particle size in the order of 0.3-0.7 microns. As already indicated, this strip when subjected to ironing 25 operations encounters severe galling. However, if the aluminum web is subjected to the homo- 25 genization step, as previously described, prior to cold rolling, the intermetallic particle size increases with increasing homogenization temperature which results in a proportionate decrease in galling when the homogenized strip is subjected to wall-ironing conditions.

The relationship between homogenization temperature, intermetallic particle size and galling is 30 summarized in the Table below: 30

TABLE

Homogenization

Temperature Intermetallic Size

35 (°F)* (Microns) Galling 35

900-950 0.5-1.0 Moderate

1000-1050 0.7-1.2 Marginal

1090-1140 1.0-3.0 None

40 40

*20 hours @ temperature

Although the aluminum web when homogenized at 950-1150°F will encounter no galling during wall-ironing a cup formed from the web, it will after being subjected to drawing operations, exhibit unacceptably high earing.

45 By following the cold roll/recovery-recrystallization heating sequence of the present invention 45 there is attained a reduction in earing to levels required for commercial acceptance of the drawn and wall-ironed container.

Thus, after the aluminum alloy stock has been produced by continuous strip casting and homogenized in accordance with the parameters disclosed above, the cooled web which has a 50 thickness of up to one inch and typically about 0.25 to about 0.50 inch in thickness is 50

subjected to a first cold rolling step to effect a total gauge reduction in excess of about 25% and preferably about 50 to about 75%. Thereafter, the cold rolled sheet is heated to a recovery temperature level.

The term "recovery temperature" as it is used in the art means the temperature at which the 55 rolled metal is heated whereby it is softened without forming a new grain structure. For 55

aluminum alloys of the 3004 type the recovery temperature is in the range of about 300 to about 550°F. The recovery temperature to which the cold rolled web may be heated after the first cold roll reduction is about 350 to about 500°F for about 2 to about 6 hours and preferably from about 425 to about 475°F for about 2 to 4 hours.

60 After being heated at the recovery temperature the heated web is cooled to ambient tempera- 60 ture and subjected to a second cold rolling step to effect a total reduction in thickness of the web of at least 10% and preferably between about 10 to about 25%.

As will hereinafter be illustrated, heating the web to a recovery temperature intermediate between the two cold rolling steps is critical to imparting a low earing characteristic to the 65 aluminum sheet. 65

4

GB 2 172 303A 4

After the second cold roll step, the temperature of the cold rolled web is raised to the "recrystallization temperature" level.

The term "recrystallization temperature", as it is used in the art, means the temperature at which the rolled metal web softens simultaneously with the formation of a completely new grain 5 structure. In the case of 3004 alloy, the grain structure changes from a substantially elongated structure to an equiaxed structure when the alloy is heated at the recrystallization temperature.

In the practice of the present invention, the recrystallization temperature is in the range of about 600 to about 900°F, the heating being effected for about 1 to about 4 hours and preferably at a temperature between about 700 to about 800°F for about 2 to about 3 hours. 10 After heating at the recrystallization temperature for the prescribed time period, the recrystal-lized web is cooled to ambient temperature and then cold rolled, e.g., to at least about 50% and preferably about 60 to about 90%, to the final gauge dictated by can performance requirements, e.g., 0.012 to 0.0145 inch and H19 temper.

To achieve an optimum reduction in earing the aluminum web is heated a second time to a 15 recovery temperature, the second recovery heating occurring between the second cold rolling step and the recrystallization heating step. The second recovery heating is effected at a temperature between about 450 and 550°F for about 0.5 to about 3 hours and preferably between about 475 to about 525°F for about 0.75 to about 1.25 hours.

In effecting the second recovery heating, the web may be cooled to room temperature 20 between the second recovery heating step and the recrystallization step. Preferably the recrystallization heating is carried out without prior cooling to room temperature by direct heating from the second recovery temperature to the recrystallization temperature.

It has been further determined that to achieve a consistency in earing reduction results it is advantageous that, after the homogenization step of the process of the present invention the 25 web is cooled in a controlled stepped manner, i.e., at a cooling rate of no more than 75°F/hr. A preferred sequence of cooling is summarized as follows:

Time to Reach

Temperature Range Lower Temperature Average Cooling 30 of Cooling, °F (Hours) Rate °F/hr

1100-900 4.0 50

900-750 2.0 75

750-375 12.5 30

35

An aluminum alloy preferred in the practice of the present invention is a 3004 aluminum alloy having incorporated therein 0.1-0.4% by weight chromium. Sheet formed from the chromium modified alloy 3004 when fabricated into a two piece drawn and wall-ironed can exhibits an improved level of buckle strength, that is, the ability of the can to withstand high internal 40 pressure without bottom inversion.

The chromium modified aluminum alloy 3004 preferred in the practice of the present invention has the following range of constituents expressed in percent by weight: about 0.5 to about 1.5% magnesium, about 0.5 to about 1.5% manganese, about 0.1 to about 1.0% iron, about 0.1 to about 0.5% silicon, 0.0 to about 0.25% zinc, 0.0 to about 0.25% copper, about 0.1 to 45 about 0.4% chromium, the balance being aluminum and incidental elements and impurities.

For sheet formed from the chromium modified alloy 3004 to perform as desired, it is essential that it be in the state resulting from a cold roll reduction of at least 50% of the material in the recrystallized state. The sheet in this state exhibits tensile yield strengths in the range of 40,000 to 45,000 psi and total elongation, measured in 2 inches gauge length samples, of 1.5% or 50 more. A tensile yield strength 40,000 to 45,000 psi in the sheet material has been found, when such sheet is drawn and wall ironed into a two piece beverage container, to correlate with a can buckle strength of at least 98 psi.

The improved properties imparted to alloy 3004, and particularly the high tensile yield strengths, by the incorporation therein of about 0.1 to about 0.4% by weight chromium is 55 totally unexpected when viewed against the teachings of the prior art.

Thus, U. S. 4,111,721 teaches that additaments to alloy 3004 such as chromium should be limited to trace amounts in the order of several hundred thousands of a weight percent or less as such additaments tend to have profound effects on the intermetallic particle sizes in the alloy. U. S. 3,834,900 teaches that the presence of chromium in the strip cast aluminum alloy should 60 be minimized, i.e., limited to a concentration of less than 0.001% by weight, to avoid casting defects.

The composition and processing limitations of the present invention must be closely followed in order to achieve the required high tensile yield strength properties which characterize the sheet prepared from continuous strip cast modified alloy of the present invention. It is critical to 65 the practice of the present invention that the chromium concentration in the alloy be strictly

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GB 2 172 303A 5

adhered to. For example, if the maximum chromium concentration levels are exceeded, problems such as fracturing during can forming may result. If chromium levels of less than about 0.1 % by weight are incorporated in the alloy, the tensile yield strength of sheet fabricated from the continuous strip cast alloy falls below the minimum requirements for beverage can performance.

5 In converting the chromium modified alloy composition of the present invention into sheet material by strip casting, the aluminum and alloying elements are charged into a melting furnace from which a stream of alloy is fed to a conventional strip caster which solidifies a web of an inch or less in thickness preferably about 0.25 to 0.50 inch in thickness. The strip cast web is fabricated into sheet having non-galling, low earing and high strength characteristics by employ-

10 ing the homogenization and cold roll/anneal process conditions of the process of the present invention.

A more thorough understanding of the present invention may be attained by reference to the following specific examples of the practice of the invention.

15 Example I

A series of strip-cast aluminum alloys having varying alloy constituents including those within the Aluminum Association Specification 3004 aluminum alloy range were evaluated for use in the fabrication of drawn and wall-ironed can bodies. The composition of the alloys is summarized in Table I below:

20

Table I

Composition of Alloys (Wt. %)

Mg

Mn

Fe

Si

Zn

Cr

Alloy I

1.07

0.94

0.32

0.22

0.06

-

Alloy II

1.14

1.12

0.23

0.28

0.02

0.11

Alloy III

1.10

1.08

0.22

0.30

0.02

-

Alloy IV

1.03

1.00

0.41

0.21

0.05

-

One foot wide by three feet long sections of the cast aluminum strip having a thickness of 0.48 30 inch were placed in a furnace in a nitrogen atmosphere, bought up rapidly to the desired temperature, and held for 10 to 40 hours at homogenization temperatures varying from 1094 to 1130°F. Thereafter, the strips were removed from the furnace and cooled to ambient temperature by blowing cold compressed air on the strips. The homogenization conditions used in the series of runs are summarized in Table II as follows:

35

Table II

Homogenization Conditions

Homogenization

Temp

Time At

Condition

(°F)

Temp (Hrs)

A

1130

30

B

1112

35

C

1094

40

D

1100

10

The cooled strips were rolled in successive passes using a commercial rolling mill until the strip was reduced to varying degrees of thickness ranging from 66 to 75% (0.160 to 0.120 inch).

The reduced thickness strips were subjected to a first recovery temperature wherein the strips 50 were placed in a furnace previously heated to 450CF and held for 3 hours after which time the strips were removed from the furnace and allowed to cool to room temperature.

After being subjected to the first cold roll/recovery temperature treatment, the strips were subjected to a second cold roll reduction by being passed successively through a pair of reduction rolls until the strip was reduced 10-25% in thickness (to 0.120 inch).

55 After the second cold roll reduction the strips were subjected to a second recovery heating at 500°F for one hour and then annealed at a recrystallization temperature of 800°F for 2 hours.

A cold roll/recovery-recrystallization (anneal) conditions to which the series of strips were subjected are summarized in Table III below.

For purposes of constrast, the cold roll/anneal conditions of Example I were repeated with the 60 exception that no recovery temperature heating was effected between the cold roll reduction step and the recrystallization step. These contrasting conditions are summarized in Table III below designated by the symbols "C," and "C2".

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Table III Cold Roll/Anneal Conditions

Cold Roll/ . Anneal Cycle

No. (°F)

1

2

°i.

1st Cold Reduction (% Red.)

72 66 75 50

1st Recovery Heating

Time @ Temp Temp (°F) (Hrs)

450 3

450 3

None

None

1st Recryst. Heatinq

Time @ • Temp Temp (°F) (Hrs)

None

None

800 3

900 2

2nd Cold Reduction (% Pod.)

10 25 Nona 40

2nd Recovery Heating Time @ Temp Temp (°F) (Hrs)

500 1

500 1

None

None

2nd Recryst. Heatinq

Temp Time

800 2 800 2

None 300 2

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GB 2 172 303A 7

The recrystallized strips were cooled to ambient temperature and then work hardened by passing the strips successively in a commercial rolling mill until the strip was reduced about 88% in thickness (H19 temper) to 0.0134 to 0.0148 inch.

The H19 temper strips were examined under a scanning electron microscope in the back 5 scattering mode and found to have an intermetallic particle size in the 1 to 3 microns range indicating that no galling would occur when the strips were subjected to the wall-ironing conditions of can making.

To determine the extent of earing which would occur when the strips were subjected to the drawing operations of can making, circular blanks 2.20 inch diameter were cut from the H19 10 hardened strips and deep drawn into shallow cups of 1.32 inch diameter with a resultant 39% reduction in diameter. The tooling used for deep drawing 0.0135 inch sheet was designed to yield about a 3.5% positive clearance (0.0005 inch) between the walls of the punch and die. A die clearance of 5% or less and a reduction in diameter of 39% is typically required in this standard test for canstock earing which simulates the drawing step of the can making process. 15 Cupping speed and blank clamping pressure were adjusted for each test to obtain a fracture and wrinkle-free cup.

The results of the earing tests using strips of the alloy compositions of Table I which had been subjected to the homogenization and cold roll/anneal conditions disclosed in Tables II and III are summarized in Tables IV and V below. Each earing test result represents an average of 20 three tests.

The results of earing tests on aluminum strips subjected to comparative cold roll/anneal cycles C, and C2 are summarized in Table VI below.

Table IV

25

Earing Test Results

Cold Roll/Anneal Cycle 1

Alloy

Homogenization

Final Sheet

Earing

Type

Condition

Gauge (inch)

%

I

A

0.0140

3.20

30

II

A

0.0148

2.96

III

A

0.0142

3.72

I

B

0.0139

3.54

II

B

0.0142

3.82

III

B

0.0146

3.58

35

IV

B

0.0142

3.03

I

C

0.0139

3.98

II

C

0.0145

3.61

III

C

0.0141

3.70

IV

D

0.0143

2.71

40

I

D

0.0142

3.14

II

D

0.0142

3.13

III

D

0.0141

3.06

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Table V

Earing Results

Cold

Roll/Anneal Cycle 2

Alloy

Homogenization

Final Sheet

Earing

Type

Condition

Gauge (inch)

%

50

I

B

0.0145

3.51

II

B

0.0143

3.43

III

B

0.0146

3.58

I

C

0.0141

4.39

55

II

C

0.0140

4.08

III

C

0.0143

4.04

I

D

0.0140

3.59

II

D

0.0143

3.36

D 0.0140 3.54

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GB 2 172 303A 8

Table VI Earing Results Cold Roll/Anneal Cycles C, and C2 5 Cold Roll Alloy Homogenization Final Sheet Earing 5

Anneal Type Condition Gauge (inch) %

cycle

C, IV A 0.0141 6.3

10 C, IV B 0.0138 5.9 10

C2 IV A 0.0139 6.1

C2 IV B 0.0143 5.2

C2 IV C 0.0144 6.6

C2 IV D 0.0142 5.7

15 15

By reference to the earing data summarized in Tables IV and V, and comparing such data to the comparative earing data in Table VI, it is readily apparent that aluminum strip treated in accordance with cold roll/anneal cycles 1 and 2 produce lower earing when compared to comparative cold roll/anneal cycles C, and C2. The data indicates that cold roll/anneal cycles 1 20 and 2 which involve one or more recovery heating steps prior to recrystallization heating are 20

more effective in reducing earing than anneal cycles C, and C2 in which there are one or more recrystallization heating steps but no recovery heating step. Cold roll/anneal cycle 1 produces superior earing results when compared to cold roll/anneal cycle 2; cycle 1 having a lower second rolling reduction (10%) than cycle 2 (25%), indicating that a low (10%) second rolling 25 reduction is desirable in reducing earing. 25

Example II

The procedure of Example I was repeated with the exception that there was simulated the heating and cooling conditions that would be expected to occur in a commercially produced 30 10-15 ton coil of continuous strip cast aluminum alloy 3004 of about 0.50 inch thickness which 30 had been subjected to the heating sequence of the present invention.

The programmed heating and cooling sequences outlined in the preferred embodiments sections of this application were used to achieve strip homogenization in these coil simulation tests. The time and temperature used in the heating and cooling sequences are summarized in Table 35 VII below: 35

40

Homogenization Temp Condition (°F)

Table VII Homogenization Conditions Time to Reach Time At Cooling Temp (Hrs) Temp Time To

(Hrs) 375°F (Hrs)

40

45

E F G

1112 1094 1094

13 13 10

35 40 10

35 40 20

45

The strips homogenized in accordance with Table VII were then cooled in accordance with the following schedule:

50

Temperature Drop °F

Time to Reach Lower Temperature (Hours)

50

55

1130 to 1100 1100 to 900 900 to 750 750 to 375

0.06 4.0 2.0 12.5

55

At 375°F the furnace was shut off and the strips allowed to cool to room temperature. 60 The cooled strips were then cold rolled/annealed in the manner of Example I using the cold 60 roll/anneal conditions summarized in Table VIII below.

For purposes of contrast, the cold roll/anneal conditions of Example II were repeated with the exception that no recovery temperature heating was effected between the cold roll reduction step and the recrystallization step. This contrasting condition is summarized in Table VIII below 65 designated by the symbol C3. 65

Table VIII Cold Roll/Anneal Conditions

Cold Roll/

1st Cold

1st

1st

2nd Cold

2nd

2nd

Anneal

Reduction

Recovery

Recryst.

Reduction

Recovery

Recryst.

Cycle

(% Red.)

Heating

Heating

(% Rod.)

Heating

Heatinq

Time @

Time @

. Time @

Temp

Temp

Temp .Temp

Temp Temp

Temp Time

Type

(°F)

(Hrs)

(°F) (Mrs)

(°F) (Hrs)

(°F) (Hrs)

5

72

450

3

None

10

500 1

800 2

6

66

450

3

None

25

500 • 1

800 2

7

75

400

4

800 2

None

None

None

8

66

500

1

800 2

25

500 1

800 2

75

None

800 3

None

None

None

10

GB2172303A 10

The heating and cooling conditions that would be expected to occur in processing a commercial coil were used in each recovery and recrystallization step. These conditions are summarized in Table IX below:

Cold Roll/ Anneal Cycle

5

6

7

8

C,

Time to

Reach

1st

Recovery Temp (Hrs)

4

4

5 5

Time to Cool to 75°F (Hrs)

6 6

Table IX Coil Simulation Heatinq/Cooling Conditions

Time to

Reach

1st

Recryst. Temp (Hrs)

4 4 7

Time to Cool to 37 5 °F (Hrs)

10 5 10

Time to Reach 2nd ' Recovery Temp (Hrs)

Time to

Reach

2nd

Recryst. Temp (Hrs)

4

Time to Cool to 375 °F (Hrs)

11 11

11

12

GB2 172 303A 12

The cooled recrystallized strips of Table IX were work hardened to H19 temper and reduced in thickness to 0.0134 to 0.0148 inch.

The H19 temper strips were examined under a scanning electron microscope in the back scattering mode and found to have an intermetallic particle size in the 1 to 3 microns range, 5 indicating that no galling would occur when the strips were subjected to the wall-ironing condi- 5 tions of can making.

The results of earing tests using strips of the alloy compositions of Table I which had been subjected to the homogenization and cold roll/anneal conditions as disclosed in Tables VIII and IX are summarized in Tables X-Xlll below. Each earing test result represents an average of 3 10 tests. 10

The results of earing tests on aluminium strips subjected to comparative cold roll/anneal cycle C3 are summarized in Table XIV below.

Table X

15 Earing Results 15

Cold Roll/Anneal Cycle 5

Alloy

Homogenization

Final Gauge

Earing

Type

Condition

(inches)

%

I

G

0.0138

3.12

II

G

.0143

3.12

III

G

0.0140

2.67

25 Table XI 25

Earing Results Cold Roll/Anneal Cycle 6

Alloy

Homogenization

Final Gauge

Earing

Type

Condition

(inches)

%

F

0.0133

4.81

II

F

0.0139

4.33

III

F

0.0138

4.65

G

0.0140

4.28

II

G

0.0142

3.36

III

G

0.0141

4.24

Table XII

40 Earing Results 40

Cold Roll/Anneal Cycle 7

Alloy

Homogenization

Final Gauge

Earing

Type

Condition

(inches)

%

45

I

F

0.0140

4.36

II

F

0.0139

4.20

III

F

0.0128

5.74

I

G

0.0136

4.28

II

G

0.0138

3.76

50

III

G

0.0139

4.14

Table XIII Earing Results

55 Cold Roll/Anneal Cycle 8 55

Alloy Homogenization Final Gauge Earing Type Condition (inches) %

I E 0.0139 3.98

60 II E 0.0139 3.98 60

III E 0.0140 4.40

13

GB2172303A 13

Table XIV Earing Results Cold Roll/Anneal Cycle C3

5 Alloy

Homogenization

Final Gauge

Earing

Type

Condition

(inches)

%

I

F

0.0131

4.66

II

F

0.0136

3.77

10 III

F

0.0133

5.99

I

G

0.0137

3.83

II

G

0.0139

4.59

III

G

0.0134

4.87

15 By reference to the data summarized in Tables X-XIII and comparing such data to that in Table XIV, it is readily apparent that the largest reduction in earing occurs when cold roll/anneal cycle 5, which employs two recovery heatings prior to recrystallization is used.

Cold roll/anneal cycle 6 which is identical to cycle 5, except that a second cold roll reduction of 25% is used instead of 10%, produces a reduction in earing, but the reduction achieved is 20 less than that achieved using cycle 5, indicating that a second cold roll reduction of 10% is more advantageous in effecting a reduction in earing.

Cold roll/anneal cycle 7 which utilizes a single recovery heating/single recrystallization heating sequence does not achieve the earing reduction level of cycle 5 but does produce a superior reducton in earing when compared to the single recrystallization heating of cold roll/anneal cycle 25 C3.

The double recovery heating/recrystallization heating of cycle 8 produces a reduction in earing when compared to control cycle C3, but does not provide an advantage over cycle 5 which utilizes only one recrystallization heating.

30 Example III

A strip-cast aluminum alloy having the alloy composition of the present invention designated by the symbol "I" was prepared as well as alloy compositions having varying alloy constituents within the 3004 specification range designated by the symbol "A". These alloys were then evaluated for use in the fabrication of drawn and wall-ironed can bodies. The composition of the 35 alloys is summarized in Table XV below:

Table XV Composition of Alloys (Wt. %)

Mg

Mn

Fe

Si

Zn

Cr

Alloy I

1.14

1.12

0.23

0.28

0.02

0.11

Alloy A,

1.07

0.94

0.32

0.22

0.06

-

Alloy A2

1.10

1.08

0.22

0.30

0.02

-

One foot wide by three feet long sections of the cast aluminum strip having a thickness of 45 0.48 inch were placed in a furnace in a nitrogen atmosphere and heated for 10 to 40 hours at homogenization temperatures varying from 1094°F to 1112°F. The heating and cooling conditions that would be expected to occur in a commercially produced 10-15 ton coil of a strip of continuous cast aluminum alloy of about 0.50 inch thickness when subjected to the programmed heating and cooling sequences preferred for homogenization and outlined in the Preferred Em-50 bodiments of this application were simulated to achieve strip homogenization. The time and temperature used in the heat and cooling sequences are summarized in Table XVI below:

Table XVI Simulated Coil

55 Homogenization Conditions

Homogenization

Temp

Time At

Cooling Time To

Condition

(°F)

Temp (Hrs)

375°F (Hours)

A

1112

35

35

B

1094

40

40

C

1094

10

20

5

10

15

20

25

30

35

40

45

50

55

60

The strips homogenized in accordance with the conditions in Table XVI were then cooled in accordance with the following schedule:

14

GB2 172 303A 14

Temperature Drop (°F)

Time to Reach Lower Temperature Hours

5

5

1130 to 1100 1100 to 900 900 to 750 750 to 375

0.6 4.0 2.0 12.5

10

10

At 375°F the furnace was shut off and the strips allowed to cool to room temperature.

The cooled strips were rolled in successive passes using a commercial rolling mill until the strip was reduced to varying degrees of thickness ranging from 66 to 75% (0.160 to 0.120 inch).

15 In a first series of cold roll/recovery-recrystallization heatings the reduced (66-72%) thickness 15 strips were subjected to a first recovery temperature wherein the strips were heated in a furnace to 450°F and held for 3 hours. After being subjected to the first cold roll/recovery temperature treatment, the strips were then subjected to a second cold roll reduction by being passed successively through a pair of reduction rolls until the strip was reduced 10-25% in thickness 20 (to 0.120 inch). 20

After the second cold roll reduction the strips were subjected to a second recovery heating at 500°F for one hour and then heated to recrystallization temperature of 800°F for 2 hours.

The first series of cold roll/recovery-recrystallization heatings was varied whereby in a first variation the second cold reduction was eliminated and recrystallization carried out immediately 25 after the first recovery heating. In a second variation, the recovery heating was eliminated and 25 recrystallization was carried out immediately after the cold reduction.

The cold roll/anneal conditions to which the series of strips were subjected are summarized in Table XVII below.

The heating and cooling conditions that would be expected to occur in processing a commer-30 cial coil were used in each recovery and recrystallization step. These conditions are summarized 30 in Table XVIII below.

Table XVII Cold Roll/Anneal Conditions

Cold/Roll

1st Cold

1st

1st

2nd Cold

2nd

2nd

Anneal

Reduction

Recovery

Recryst.

Reduction

Recovery

Recryst.

Cycle

(% Red.)

Heating

Heatinq

(% Pod.)

Heatinq

Heatinq

Time @

Time @

Time @

Temp

Temp

Temp Temp

Temp Temp

Temp Time

>F)

(Hrs)

(°F) (Hrs)

(•F) (Hrs)

(#F)

1

72

450

3

None

10

500 1

800 2

2

66

450

3

None

25

500 1

800 2

3

75

400

4

800 2

None

None

None

4

66

• 500

1

800 2

25

500 .1

800 2

5

75

None

800 3

None

None

None

Cold/ Roll Anneal Cycle

1

2

3

4

5

Time to Reach 1st Recovery Temp (Hrs)

4

4

5 5

Table XVIII Coil Simulation Heating/Cooling Conditions

Time to Time to Time to

Cool to Heat to 1st Cool to

75°F Recryst. 375°F

(Hrs) Temp (Hrs) (Hrs)

6 6

4 4 7

10 5 10

Time to Rcach 2nd Recovery Tonp (Hrs)

5 5 5 5

Time to Heat to 2nd Recryst. Temp (Hrs)

4

4 .

4

Time to Cool to 37 5°F (Hrs)

11 11

17

GB2172303A 17

The recrystallized strips were cooled to room temperature and then were hardened by passing the strips successively in a commercial rolling mill until the strip was reduced about 88% in thickness (H19 temper) to 0.0133 to 0.0148 inch.

The H19 tempered strips were examined under a scanning electron microscope in the back 5 scattering mode and found to have in intermetallic particle size in the 1 to 3 microns range, 5

indicating that no galling would occur when the strips were subjected to the wall-ironing conditions of can making.

To determine the level of earing that would occur when the strips were subjected to the drawing operations of can making, circular blanks 2.20 inch diameter were cut from the H19 10 hardened strips and deep drawn into shallow cups of 1.32 inch diameter with a resultant 39% 10 reduction in diameter. The tooling used for deep drawing was designed to yield about a 3.5%

positive clearance (0.0005 inch) between the walls of the punch and die. A die clearance of 5%

or less and reduction in diameter of 39% is typically required in this standard test for earing which simulates the drawing step of the can making process. Cupping speed and blank blamping 15 pressure were adjusted for each test to obtain a-fracture and wrinkle-free cup. 15

The results of the earing tests using strips of the alloy compositions of Table XV which had been subjected to the homogenization and cold roll/anneal conditions disclosed in Tables XVI and XVII are summarized in Tables XIX-XXI below. Each earing test result represents an average of three tests.

20 The mechanical properties of the H19 hardened strips in tension, i.e. yield strength, ultimate 20 strength and tensile total elongation were determined in accordance with the ASTM Test Procedure Number E-8 using 2 inches gauge length test specimens. Each mechanical test result represents an average of six tests, three measured in the direction longitudinal and three in transverse to the rolling direction. The results of these tests are also recorded in Tables XIX-XXI 25 below. 25

It had been previously determined that the buckle strength of cans formed from continuous strip cast aluminum alloy 3004 correlates closely with the tensile yield strength of the H19 temper sheet. The correlation between buckle strength and tensile yield strength is summarized in Table XXII below.

30 The tensile ultimate strength, along with the tensile total elongation, is a measure of sheet 30

formability. To be suitable for can body manufacture, the sheet must have a tensile ultimate strength of at least 42,000 psi.

Tensile total elongation measured in percent is a measure of ductility. To be suitable for can body manufacture the sheet must have a tensile total elongation of at least 1.5%.

Table XIX Earing/Mechanical Tests Alloy I

Homogenization Condition

C B C B C A C

Cold Roll/Anneal Cycle

1

2

2

3

3

4 5-

Earing %

3

4 ,

3,

4,

12 33 36 20

3.76 3.98 4.59

Mechanical Tests (In Tension)

Yield Strength

• « 3 psi, 10

42.3 41.1 41.7 40.7 42.1 40.0 42.7

Ultimate Strength Total

3

psi, 10 Elongation

%

44.5 43.2

44.2

42.3

44.7

41.8 45.5

2.3 2.2

2.2

2.3 2.5 2.3 2.3

Table XX Earing/Mechanical Tests Alloy Al

Homogenization Cold Roll/Anneal Earing Mechanical Tests {In Tension)

Condition Cycle %

Yield Strength Ultimate Strength Total

3 3

psi, 10 psi, 10 Elongation

%

C

1

3.12

40.6

43.8

2.4

B

2

4.81

38.0

39.8

2.2

C

2

4 . 28

40.1

42.4

2.2

B

3

4.36

39.2

41.0

2.4

A

4

3.98

38.5

40.8

2.3

B

5

4.66

39.5

41.5

2.1

Homogenization Condition

B C B C A B

Table XXI Earing/Mechanical Tests Alloy A2

Cold Roll/Anneal Earing Cycle %

2

2

3

3

4

5

4 .65 4.24 5.74 4.14 4.40 5.99

Mechanical

Yield Strength 3

psi, 10

36.4

39.5 35.4 38.9 37.1 39.0

Ultimate Strength psi, 10

38.4 42.0

37.5 42.8 39.0 41.2

Total

Elongation %

2.1 2.1 i.9

2.0

2.1 2.0

21

GB2172303A 21

Table XXII

Tensile Yield Strength/Buckle Strength Correlation in Can Body Stock Alloy 3004-H19 Prepared

From Continuous Strip Cast Web # **

Tensile Yield Strength (psi, 103) Buckle Strength (psi)

36.3

83.7

36.8

85.2

37.4

88.5

37.8

90.9

38.2

89.5

38.7

92.5

39.6

94.0

39.8

97.0

40.5

98.5

40.6

99.0

41.3

100.0

42.7

101.0

42.5

102.0

20 * Average of six tests, three for longitudinal and three for transverse samples with respect to 20 the rolling direction.

** Buckle strength measured for 0.0135 "sheet thickness, or adjusted for gauge at the rate of 1 psi for 0.0001" variation.

By reference to Table XIX it is immediately apparent that the incorporation of 0.11% by 25 weight chromium in aluminum alloy 3004 improves the tensile yield strength and thereby the 25

corresponding buckle strength without any deleterious effect on the can formability of sheet formed from the alloy. Thus the tensile yield strength of Alloy I generally exceeds 40,000 psi reflecting a buckle strength in excess of 98 psi. Similarly, the tensile ultimate strength of Alloy I is in excess of the minimum requirement of 1.5%.

30 By comparing the data recorded in Tables XX and XXI with that of Table XIX it is immedi- 30 ately apparent that conventional 3004 alloy, such as alloys A, and A2, when processed in accordance with the same conditions of Alloy I have buckle strength substantially lower than that of Alloy I.

35 Example IV 35

A second series of strip cast aluminum alloys were evaluated for use in the fabrication of drawn and wall ironed can bodies. The composition of the alloys is summarized in Table XXIII below:

40 Table XXIII 40

Composition of Alloys (Wt. %)

Mg Mn Fe Si Zn Cr Cu

Alloy A 1.13 1.15 0.46 0.17 0.07 0.26 0.15

Alloy B 0.90 0.96 0.35 0.13 0.06 0.25 0.15

45 Alloy C 1.05 1.03 0.49 0.19 0.07 0.20 0.15 45

Copper was incorporated in the alloys to simulate aluminum can scrap which had been found to contain 0.1 to 0.2 percent by weight copper.

The aluminum alloys were continuously cast, using a Hunter type twin roll caster into sheet 50 0.26 inches thick which were wound into 5000 pound coils. The coils were allowed to reach 50 room temperature over a 48 hour period. The cooled coils were then placed in a furnace and homogenized in a nitrogen atmosphere. The coil was brought up to 1076°F ±7°F over a 12 hour period and held at that temperature for 16 hours. Thereafter, the coils were allowed to cool in the furnace to 200°F over a 32 hour period. The cooled coils were removed from the 55 furnace and further allowed to cool to room temperature over the next 48 hours. 55

The room temperature cooled coils were subjected to a first cold roll/recovery temperature treatment wherein the cooled coils were rolled in successive passes using commercial rolling equipment until each of the coils was reduced to varying degrees of thickness varying from 83 to 85% (0.052 to 0.059 inches).

60 The reduced thickness coils were subjected to a first recovery temperature wherein the coils 60 were placed in a furnace and heated to 450°F ±3°F over a 4 hour period and held at this temperature for 4 hours whereupon the coils were allowed to cool in the furnace to 300°F over a period of nine hours. The coils were removed from the furnace and allowed to cool to room temperature over the next 48 hours.

65 After being subjected to the first cold roll/recovery temperature treatment, the coils were 65

22

GB 2 172 303A 22

subjected to a second cold roll reduction by being passed successively through a pair of reduction rolls until each of the coils was reduced 25% in thickness (0.039 to 0.044 inches).

After the second cold roll reduction, the coils were placed back in the furnace and subjected to a second recovery heating by raising the temperature of the furnace to 500°F over a 3.5 hour 5 period, and holding at that temperature for 1.5 hours. The coils were annealed at the recrystallization temperature by raising the temperature of the furnace to 800°F over a 6 hour period and held at this temperature for 3 hours. The coils were allowed to cool in the furnace to 300°F over a 14 hour period and then removed from the furnace and allowed to cool to room temperature over the next 48 hours.

10 The recrystallized coils were then work hardened by passing the coils successively in a commercial rolling mill until the coil was reduced about 65 to 67% in thickness to 0.0135 inches.

The work hardened coils were then fabricated into two-piece aluminum beverage cans on a commercial drawn and wall ironing manufacturing line, about 5000 cans being fabricated from 15 each coil. No galling was encountered. Earing ranged from 2.0 to 2.6%.

The cans were also evaluated for buckle strength, i.e., ability of the can to withstand high internal pressure without buckling.

Buckle strength is determined by applying pressure within a drawn and wall-ironed can and then gradually increasing the pressure until the bottom end of the can deforms and bulges out, 20 i.e., it buckles. The pressure at which the bottom buckles is then designated as the buckle strength. To be acceptable as can body stock, a can formed from the alloy sheet must exhibit a buckle strength of at least 90 pounds per square inch (psi).

The average buckle strength for cans fabricated from alloys A, B and C in the above manner are recorded in the Table XXIV below:

25

Table XXIV

Alloy Buckle Strength (psi)

A 96

B 88

30 C 94

Claims (5)

1. An aluminum alloy sheet fabricated from a continuous strip cast aluminium alloy having a 35 thickness of up to one inch, characterized in that said sheet has a thickness of 0.008 to 0.017
inch and has received a reduction in thickness of at least 50% by cold rolling to provide a hard temper, the alloy being comprised of about 0.5 to about 1.5% by weight magnesium, about 0.5 to 1.5 by weight manganese, about 0.1 to about 1.0% by weight iron, about 0.1 to about 0.5% by weight silicon, about 0.0 to about 0.25% by weight zinc, about 0.0 to about 0.25% 40 by weight copper and about 0.1 to about 0.4% by weight chromium.
2. The aluminium alloy sheet of Claim 1, characterized in that the hard condition sheet has a tensile yield strength of at least 40,000 psi, a tensile ultimate strength of at least 42,000 psi and a tensile total elongation of at least 1.5%.
3. The sheet of Claim 1, characterized in that the sheet has received a cold reduction of at 45 least 50%.
4. An aluminium alloy suitable for the manufacture of can body stock, characterized in that said alloy comprises about 0.5 to about 1.5% by weight magnesium, about 0.5 to 1.5% by weight manganese, about 0.1 to about 1.0% by weight iron, about 0.1 to about 0.5% by weight silicon, about 0.0 to about 0.25% by weight zinc, about 0.0 to about 0.25% by weight
50 copper and about 0.1 to about 0.4% by weight chromium.
Amendments to the claims have been filed, and have the following effect:—
(a) Claims 1-4 above have been deleted or textually amended.
(b) New or textually amended claims have been filed as follows:-
55 1. An aluminium alloy sheet fabricated from a continuous strip cast aluminium alloy having a thickness of up to 2.54 cm (one inch), characterized in that said sheet has a thickness of 0.020 to 0.043 cm (0.008 to 0.017 inch) and has received a reduction in thickness of at least 50% by cold rolling to provide a hard temper, the alloy being comprised of 0.5 to 1.5% by weight magnesium, 0.5 to 1.5% by weight manganese, 0.1 to 1.0% by weight iron, .1 to 0.5% by 60 weight silicon, 0.0 to 0.25% by weight zinc, 0.0 to 0.25% by weight copper and 0.1 to 0.4% by weight chromium, the balance being aluminium.
2. The aluminium alloy sheet of Claim 1, characterized in that the hard condition sheet has a tensile yield strength of at least 275.6X 106N/m2(40,000 psi), a tensile ultimate strength of at least 289X106 N/m2 (42,000 psi) and a tensile total elongation of at least 1.5%. 65 3. An aluminium alloy sheet according to Claim 1 substantially as hereinbefore described in
5
10
15
20
25
30
35
40
45
50
55
60
65
23
GB 2 172 303A 23
any one of the foregoing Examples.
4. An aluminium alloy suitable for the manufacture of can body stock, characterized in that said alloy comprises 0.5 to 1.5% by weight magnesium, 0.5 to 1.5% by weight manganese, 0.1 to 1.0% by weight iron, 0.1 to 0.5% by weight silicon, 0.0 to 0.25% by weight zinc, 0.0 to
5. An aluminium alloy according to Claim 4 substantially as hereinbefore described in any one of the foregoing Examples.
Printed in the United Kingdom for Her Majesty's Stationery Office, Dd 8818935, 1986, 4235.
Published at The Patent Office, 25 Southampton Buildings, London, WC2A 1AY, from which copies may be obtained.
5 0.25% by weight copper and 0.1 to 0.4% by weight chromium, the balance being aluminium. 5
GB8519274A 1982-07-15 1985-07-31 Aluminium alloy sheet Expired GB2172303B (en)

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US06483337 US4517034A (en) 1982-07-15 1983-04-08 Strip cast aluminum alloy suitable for can making

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5616189A (en) * 1993-07-28 1997-04-01 Alcan International Limited Aluminum alloys and process for making aluminum alloy sheet
WO1998001592A1 (en) * 1996-07-08 1998-01-15 Alcan International Limited Cast aluminium alloy for can stock
US7304150B1 (en) 1998-10-23 2007-12-04 Amgen Inc. Methods and compositions for the prevention and treatment of anemia

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Publication number Priority date Publication date Assignee Title
US4976790A (en) * 1989-02-24 1990-12-11 Golden Aluminum Company Process for preparing low earing aluminum alloy strip
WO1998035069A1 (en) * 1997-02-05 1998-08-13 Alcan International Limited A process of reducing roping in automotive sheet products
JP3913260B1 (en) * 2005-11-02 2007-05-09 株式会社神戸製鋼所 Aluminum alloy cold-rolled sheet for excellent bottle cans in the neck formability
CN104284745A (en) * 2012-03-07 2015-01-14 美铝公司 Improved 6xxx aluminum alloys, and methods for producing the same

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US3787248A (en) * 1972-09-25 1974-01-22 H Cheskis Process for preparing aluminum alloys
US4111721A (en) * 1976-06-14 1978-09-05 American Can Company Strip cast aluminum heat treatment
DE2810188A1 (en) * 1978-03-09 1979-09-13 Metallgesellschaft Ag Heat treating continuously cast and rolled aluminium alloy strip - consists of annealing to obtain good combination of strength and deep drawing properties
DE2929724C2 (en) * 1978-08-04 1985-12-05 Coors Container Co., Golden, Col., Us
US4235646A (en) * 1978-08-04 1980-11-25 Swiss Aluminium Ltd. Continuous strip casting of aluminum alloy from scrap aluminum for container components

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5616189A (en) * 1993-07-28 1997-04-01 Alcan International Limited Aluminum alloys and process for making aluminum alloy sheet
WO1998001592A1 (en) * 1996-07-08 1998-01-15 Alcan International Limited Cast aluminium alloy for can stock
GB2333530A (en) * 1996-07-08 1999-07-28 Alcan Int Ltd Cast aluminium alloy for can stock
US6120621A (en) * 1996-07-08 2000-09-19 Alcan International Limited Cast aluminum alloy for can stock and process for producing the alloy
GB2333530B (en) * 1996-07-08 2000-10-11 Alcan Int Ltd Cast aluminium alloy for can stock
US7304150B1 (en) 1998-10-23 2007-12-04 Amgen Inc. Methods and compositions for the prevention and treatment of anemia
US7973009B2 (en) 1998-10-23 2011-07-05 Amgen Inc. Methods and compositions for the prevention and treatment of anemia
US7977311B2 (en) 1998-10-23 2011-07-12 Amgen Inc. Methods and compositions for the prevention and treatment of anemia
US8268588B2 (en) 1998-10-23 2012-09-18 Amgen Inc. Methods and compositions for the prevention and treatment of anemia

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