WO1992004476A1 - Feuilles en alliage d'aluminium - Google Patents

Feuilles en alliage d'aluminium Download PDF

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Publication number
WO1992004476A1
WO1992004476A1 PCT/US1991/006374 US9106374W WO9204476A1 WO 1992004476 A1 WO1992004476 A1 WO 1992004476A1 US 9106374 W US9106374 W US 9106374W WO 9204476 A1 WO9204476 A1 WO 9204476A1
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Prior art keywords
weight percent
sheet
aluminum alloy
alloy
strip
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Application number
PCT/US1991/006374
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English (en)
Inventor
Ivan M. Marsh
Donald C. Mcauliffe
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Golden Aluminum Company
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US07/577,880 external-priority patent/US5104465A/en
Application filed by Golden Aluminum Company filed Critical Golden Aluminum Company
Priority to AU87562/91A priority Critical patent/AU659108B2/en
Priority to MX9201202A priority patent/MX9201202A/es
Publication of WO1992004476A1 publication Critical patent/WO1992004476A1/fr
Priority to NO93930792A priority patent/NO930792L/no

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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
    • C22F1/047—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon of alloys with magnesium as the next major constituent
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C21/00—Alloys based on aluminium
    • C22C21/06—Alloys based on aluminium with magnesium as the next major constituent

Definitions

  • This invention relates to the production of aluminum sheet stock having reduced earing and improved strength which is suitable for conversion into useful products, such as container ends and container bodies.
  • Aluminum beverage containers are generally made in two pieces, one piece forming the container sidewalls and bottom (collectively referred to herein as "container body") and a second piece forming the container top.
  • container body is formed by cupping a circular blank of aluminum sheet and then drawing and ironing the cupped sheet by subsequently extending and thinning the sidewalls by passing the cup through a series of dies with diminishing bores. The result is an integral body with sidewalls thinner than the bottom.
  • a common alloy used to produce container bodies is .AA 3004 (an alloy registered with the Aluminum Association) whose characteristics are appropriate for the drawing and ironing process due primarily to low magnesium (Mg) and manganese (Mn) concentrations.
  • alloys such as AA 3004 having low magnesium content usually possess insufficient strength to be used for the fabrication of container ends with easy open "ring pulls" or the like. Therefore, alloys with a higher magnesium concentration, such as AA 5082 or AA 5182 alloys, are used for container ends.
  • Table 1 provides a comparison of the major components of alloys AA 3004, 5082 and 5182, as well as other alloys discussed herein.
  • a completed container (a body together with an end) must be able to withstand an internal pressure of at least about 60 psi if it is to contain unpasteurized beer and at least about 90 psi if it is to contain pasteurized beer, soda pop, or any beverage having similarly high carbonation levels.
  • containers fabricated from AA 3004 body alloy and AA 5082 end stock are able to withstand 90 psi of internal pressure if fabricated from aluminum sheet having a gauge of about 0.0116 inches.
  • Containers made from thinner gauges employ less sheet material than those made from thicker gauges and are therefore less expensive to produce.
  • containers made from thinner gauge stock, such as 0.0110 inches have not been sufficiently strong to withstand 90 psi of internal pressure or have not been sufficiently strong to survive the rigors encountered during long distance transportation.
  • earing percentage refers to the 45° earing or 45° rolling texture. This value is determined by measuring the height of ears which stick up in a drawn cup minus the height of valleys between the ears. This difference is divided by the height of the valleys times 100 to convert to a percentage.
  • the 45° earing is measured at 45° to the longitudinal axis of the strip. Due to this earing, the rim of the shell often becomes deformed and takes on a scalloped appearance. Because this earing must be removed before the container body is completed, waste occurs. Furthermore, excessive earing, greater than about 2 percent as measured by the Olsen cup test, may also interfere with the drawing apparatus. Minimizing earing helps to minimize waste and simplifies the production process.
  • One step that has been used to reduce earing is to reduce the cold work percentage (or the percent thickness reduction during the step of cold rolling an alloy sheet) .
  • the cold work percentage or the percent thickness reduction during the step of cold rolling an alloy sheet.
  • the yield strength also decreases as the cold work percentage decreases. Therefore, increasing the cold work to form stock with thinner gauges or greater strength produces unacceptably high earing. Conversely, reducing the earing by reducing the cold work results in thicker stock with relatively low strength.
  • Aluminum alloys may be produced by direct chill casting of molten alloy into ingots which are then rolled into strips or may be produced by a continuous strip casting process. Apparatus for continuous strip block casting is described in U.S. Patent Nos. 3,709,281, 3,744,545, 3,747,666, 3,759,313 and 3,774,670. Although there exist numerous variations of the continuous block casting process, all of the processes generally include the steps described hereinbelow. Molten aluminum alloy is injected through a nozzle or distributor tip into a cavity formed between two sets of oppositely rotating chilled blocks. While in the cavity, the alloy cools and solidifies to form an aluminum sheet. The aluminum sheet then passes between rollers to further reduce the thickness of the strip. This is typically referred to as hot rolling.
  • the continuous strip comes out of the hot rolling step, it is coiled and allowed to cool.
  • the cooled coil is then cold rolled to reduce its thickness still further.
  • the strip will be cold rolled in several passes with an intermediate annealing step between each cold rolling pass.
  • the alloy strip When the alloy strip has been reduced to its final thickness, it can be cut into appropriate shapes for the production of useful products, such as container bodies or container ends. Typically, at various stages of the process, scrap is produced (plant scrap) .
  • a first cold rolling stage reduces the thickness by at least 50 percent and is followed by a flash annealing stage at 350°C to 500°C for less than 90 seconds.
  • a second cold rolling stage results in further reduction of up to 75 percent.
  • U.S. Patent No. 3,560,269 by Anderson et al. discloses an aluminum alloy, the composition of which is set forth in Table 1.
  • An ingot is cast by direct chill casting, heated to 800°F, and held at that temperature for 24 hours.
  • the ingot is hot rolled and the resulting strip is annealed at 700°F.
  • a first cold rolling stage reduces the thickness by at least 85 percent and is followed by annealing at 600°F.
  • An optional second cold rolling stage provides further reduction of at least 30 percent to a final thickness.
  • the resulting sheet is described as having earing of not more than 3 percent, an amount which, according to the inventors, is acceptable.
  • alloy for container ends differ from those of container bodies; melting recycled aluminum containers (a combination of ends and bodies) produces a melt which may be unsatisfactory for the production of either container bodies or container ends.
  • the weight percents of the components of a typical melt of recycled aluminum comprising approximately 25 percent container ends and 75 percent container bodies are shown in Table 1. Efforts have been made to produce an alloy from recycled aluminum containers which is suitable for both container bodies and container ends.
  • U.S. Patent Nos. 4,235,646, 4,260,419 and 4,282,044 each disclose a continuous strip casting process in which the alloy strip (having the composition previously described) is held at a temperature between 400°C and 600°C for 2 to 15 minutes after it has been cast. It is then hot rolled for a thickness reduction of at least 70 percent, coiled and allowed to cool to room temperature. The strip is then uncoiled and cold rolled to a final thickness in either one or two steps. If cold rolling occurs in two steps, the first results in a reduction of at least 50 percent and is followed by a flash anneal in which the alloy is heated to between 350°C and 500°C and then cooled down to room temperature, all within a period not exceeding 90 seconds. The alloy is cold rolled a second time producing additional reduction of 75 percent or less.
  • U.S. Patent No. 4,269,632 and 4,260,419 disclose direct chill casting methods of the melt described above in which the resulting cast ingot is held at a temperature between 550°C and 600°C for 4 to 6 hours and then allowed to cool. It is hot rolled when its temperature is between 450°C and 510°C producing a thickness reduction of between 40 percent and 96 percent. The resulting strip is hot rolled a second time for an additional reduction of between 70 percent and 96 percent. The strip is coiled and then annealed in one of two ways. It may be flash annealed for 30 to 90 seconds between 350°C and 500°C or, it may be annealed for 2 to 4 hours between 315°C and 400°C. After annealing, the strip is allowed to cool and is then cold rolled in one or more stages to produce a total reduction of approximately 89 percent in thickness. After each cold rolling stage, the alloy is annealed using either a flash or conventional method.
  • U.S. Patent No. 4,411,707 discloses a process for producing container ends from the previously described scrap melt using a variation of the continuous chill roll casting method.
  • the molten alloy between 682°C and 710 °C, is cast to a thickness between 0.23 and 0.28 inches and then rolled to reduce the thickness to approximately 25 percent.
  • the strip is coiled and allowed to cool to room temperature after which it is cold rolled in at least two stages. In the first, a reduction of at least 60 percent in thickness occurs and in the second, a reduction of at least 85 percent occurs.
  • the alloy is annealed for approximately 2 hours at 440°C to 483°C between the two cold rolling stages. Additional cold rolling/annealing stages can be used if desired.
  • the composition of the alloy is set forth in Table 1. Any conventional casting method may be used (although a preference is stated for direct chill casting) after which the alloy is homogenized for 2 to 24 hours between 850°F and 1150°F.
  • the metal is then hot rolled at least twice, the first time achieving at least a 20 percent reduction in thickness at a temperature between 650°F and 950°F and the second, also achieving at least a 20 percent reduction, between 400°F and 800 ⁇ F.
  • the alloy is then annealed between 200°F and 450°F for a period greater than 5 seconds (preferably between 30 minutes and 8 hours) .
  • the aluminum strip may be cold rolled and annealed two or three times to obtain the final thickness.
  • U.S. Patent No. 4,318,755 by Jeffrey et al., issued on March 9, 1982 discloses an aluminum alloy, the composition of which is set forth in Table 1, suitable for container bodies made from recycled containers using continuous strip casting methods.
  • the strip exits the caster at 380°C to 450°C and is hot rolled to reduce the thickness between 72 percent and 82 percent; the strip exits the hot roller between 150°C and 200°C and is coiled.
  • the strip is then cold rolled to its final thickness and is either annealed for 2 hours between 400°C and 420°C or flash annealed.
  • aluminum sheet is provided.
  • the aluminum sheet is suitable for the fabrication of both container ends and container bodies in gauges thinner than typically currently employed, has low earing properties and can be formed at least in part from recycled aluminum scrap.
  • An initial alloy melt may be formed from aluminum scrap, including plant, container and consumer scrap, which is then adjusted to form the alloy composition of the present invention.
  • This composition preferably includes: about 1.9 percent to about 2.8 percent magnesium; about 0.9 percent to about 1.6 percent manganese; the balance being essentially aluminum.
  • the adjusted melt is preferably cast into strips and is hot rolled to a first thickness. The hot rolled strip is annealed and then cold rolled in at least one pass to a final gauge.
  • the aluminum sheet of the present invention provides the technical advantage of having low earing and being suitable for fabrication of both container ends and container bodies in thinner gauges than are possible using prior known sheets.
  • the present invention has the further technical advantage of permitting the aluminum alloy stock to be derived from aluminum scrap.
  • Figure 1 is a graph illustrating relationships between yield strength and cold work, and earing and cold work
  • Figures 2 and 2a are a flowchart of embodiments of a process useful for the fabrication of aluminum sheet of the present invention
  • Figure 3 is a chart illustrating the effect of altering the manganese and magnesium concentrations on strength and earing characteristics of aluminum sheets of the present invention.
  • Figure 4 is a chart illustrating the affect of cold work on the earing percentage of a direct cast prior art alloy and a block cast alloy of the present invention.
  • an aluminum strip or sheet stock is provided.
  • the term "sheet” refers to a cast piece of aluminum having a length and width substantially longer than the thickness, and includes coils, strips, flat stock, can blanks and lid stock.
  • the sheet stock has a reduced earing percentage and improved strength in thinner gauges than aluminum sheet that is presently fabricated.
  • the sheet stock can be fabricated from an alloy having a composition which can be derived, at least in part, from recycled aluminum scrap.
  • the sheet stock can be fabricated using a process which includes the steps of casting, hot rolling, annealing and cold rolling.
  • the aluminum sheet of the present invention is especially suitable for use in the fabrication of deep drawn and ironed articles, such as beverage container bodies, as well as beverage container ends.
  • an aluminum alloy composition especially suitable for the manufacture of aluminum sheet of the present invention preferably includes at least about 0.9 weight percent manganese, more preferably from about 1.1 weight percent to about 1.6 weight percent manganese, and most preferably from about
  • the alloy composition further includes from about 1.9 weight percent to 2.8 weight percent magnesium, preferably from about 2.0 weight percent to about 2.6 weight percent magnesium. Certain narrower embodiments within these ranges are preferred, as will be discussed hereinbelow.
  • the aluminum alloy preferably includes: from about 0.13 weight percent to about 0.25 weight percent silicon, more preferably from about 0.15 weight percent to about 0.20 weight percent silicon; from about 0.15 weight percent to about 0.28 weight percent copper, more preferably from about 0.20 weight percent to about 0.25 weight percent copper; and from about 0.25 weight percent to about 0.40 weight percent iron, more preferably from about 0.30 weight percent to about 0.35 weight percent iron; the balance being essentially aluminum.
  • the foregoing constitute the primary alloying elements of the aluminum alloy.
  • traces of other elements such as titanium, chromium and zinc, may be present in the composition. It is preferred that the level of zinc not exceed about 0.12 weight percent, that the level of titanium not exceed about 0.03 weight percent and that the total chromium not exceed about 0.05 weight percent. It is preferable that any additional impurities do not exceed a total of about 0.2 weight percent, or more than about 0.05 weight percent individually.
  • the amounts of magnesium and manganese can vary within the above-described ranges, and an alloy suitable for the manufacture of drawn and ironed container bodies will still result.
  • an alloy suitable for the manufacture of drawn and ironed container bodies will still result.
  • certain preferred ranges for the magnesium and manganese alloying elements within these broad ranges. These preferred alloys are listed in Table 2.
  • Alloy D includes from about 2.0 to about 2.1 weight percent magnesium.
  • Alloy E includes from about 2.45 weight percent to about 2.55 weight percent magnesium, and both alloys preferably include about 1.1 weight percent to about 1.2 weight percent manganese.
  • the ratio of magnesium to manganese is preferably less than about 3.2:1, more preferably less than about 2.2:1. It has been found that decreasing the ratio of magnesium to manganese (that is, increasing the amount of manganese relative to the magnesium, or decreasing the amount of magnesium relative to the manganese) permits a hot rolled strip of the present alloy to tolerate greater cold work, thus increasing the strength and reducing the thickness, without increasing the earing. While not wishing to be bound by theory, it is believed that each 0.1 weight percent increase in the concentration of manganese increases the yield strength of an aluminum sheet formed from the alloy by approximately 660 psi (4.5 MPa) .
  • Increasing the cold work percentage during processing may also increase the yield strength; however, cold working also tends to increase the earing percentage when an alloy blank is drawn and ironed into a beverage container.
  • Figure 1 graphically illustrates these relationships for an AA 5017 alloy.
  • the strip stock produced from the alloy and process of the present invention can advantageously provide increased yield strength by increasing the amount of manganese in the alloy, but maintains a low earing percentage.
  • the alloy used to fabricate the aluminum sheet of the present invention may be obtained by melting the primary constituents together or may be obtained by adjusting the composition of a melt of scrap aluminum.
  • scrap aluminum refers to aluminum that may comprise plant, container and consumer scrap in which container body alloy, eg. AA 3004, and container end alloy, eg. AA 5082 and AA 5182, are present in a weight ratio of approximately 3:1.
  • container body alloy eg. AA 3004
  • container end alloy eg. AA 5082 and AA 5182
  • such a scrap melt will typically have a manganese content of approximately 0.8 weight percent and a magnesium content of approximately 1.5 weight percent.
  • Adjustment to provide the composition of the present invention can involve the addition of unalloyed aluminum, manganese, magnesium or combinations of the three.
  • the aluminum sheet of the present invention can be fabricated from aluminum alloy compositions utilizing any means known in the art, for example, direct chill casting, ingot casting, or block casting. According to the present invention, it is preferable to utilize a block casting technique.
  • a block casting technique is shown graphically in the flowchart of Figures 2 and 2a.
  • the block caster is preferably of the type disclosed in U.S. Patent Nos. 3,709,281, 3,744,545, 3,747,666, 3,759,313 and 3,774,670.
  • the melt is preferably cast through a nozzle, for example with a 16 millimeter tip.
  • the melt is cast in a casting cavity formed by opposite pairs of rotating blocks, preferably to a thickness of less than about 0.8 inches (20 mm) , and more preferably from about 0.6 to 0.8 inches (about 15.2 mm to 20 mm) .
  • the strip of metal cools as it travels and solidifies along with the chilling blocks until the strip exits the casting cavity where the chilling blocks separate from the cast strip and travel to a cooler where the chilling blocks are cooled.
  • the rate of cooling as the cast strip passes through the casting cavity of the chill block casting machine is controlled by various process and product parameters. These parameters include the composition of the material being cast, the strip gauge, the chill block material, the length of the casting cavity, the casting speed and the efficiency of the chill block cooling system. It is preferred that the cast strip be as thin as possible. This minimizes subsequent working of the strip. Normally, a limiting factor in obtaining minimum strip thickness is the size of the distributor tip of the caster.
  • the strip is cast at a thickness from about 0.6 to about 0.8 inches (15.2 mm to 20 mm). However, thinner strip can be cast.
  • the cast strip normally exits the block caster in the temperature range from about 850°F to about 1100°F (about 450°C to 595°C) .
  • the cast strip is then subjected to a hot rolling operation in a hot mill.
  • the cast strip preferably enters the first hot rollers at a temperature in the range from about 880°F to about 1000°F (about 470°C to 540°C) , and more preferably in the range from about 900°F to about 975°F (about 480°C to 525°C) .
  • the hot rollers preferably reduce the thickness of the strip by at least about 70 percent and more preferably by at least about 80 percent. It is preferred to maximize the percentage reduction in the hot mill.
  • the temperature of the strip exiting the hot mill is minimized.
  • the exit temperature from the hot mill should be no more than about 660°F (about 345°C) , and is preferably from about 630°F to about 660°F (about 330°C to 345°C) .
  • this temperature is preferably minimized, an increased percentage hot mill reduction will lead to higher exit temperatures.
  • the strip is preferably held at the hot mill exit temperature for a period of time, coiled and then annealed (also known as heat treatment) . It is believed that this annealing step is critical to reducing the earing in the final strip stock.
  • the coiled strip is annealed for at least about three hours, preferably at a temperature from about 820°F to about 830°F (about 435°C to 445°C) .
  • the coiled strip can be annealed for less than about 3 hours at a temperature from about 775°F to about 830°F (about 410°C to 445 ⁇ C) .
  • the temperature of the coil upon exiting the annealing step is preferably about 500°F (about 260°C) , and it is allowed to cool to ambient temperature.
  • the strip may be self- annealed by coiling the strip very tightly and allowing it to cool slowly to ambient temperature. This process may take as long as two days or more, but is advantageous since no additional heat is necessary to anneal the strip and thus energy costs are reduced.
  • the annealed coil After the annealed coil has cooled to ambient temperature, it is cold rolled to a final gauge in at least one stage of cold roll passes, and preferably in two stages. In the first cold rolling stage, the thickness is preferably reduced by about 40 percent to about 80 percent.
  • the first cold rolling stage can include a single cold roll pass.
  • at least two cold roll passes are employed, the first pass causing a thickness reduction of up to about 40 percent and the second cold roll pass causing an additional reduction of about 35 percent to about 70 percent. It has been found that cold rolling using at least two cold roll passes in the first cold rolling stage produces a cast strip having better uniformity.
  • the temperature of the strip upon its exit from each cold rolling pass is approximately 150°F to 200°F (about 65°C to 95°C) due to the friction of the rollers on the alloy strip.
  • the strip is preferably annealed for about 3 hours at from about 650°F to about 700°F (about 340°C to 375°C) , more preferably at from about 670°F to about 680°F (about 355°C to 360°C) .
  • This intermediate anneal improves the formability and earing characteristics of the final strip.
  • the cold rolled and annealed strip After the cold rolled and annealed strip has cooled to ambient temperature, it goes through a second cold rolling stage in which the thickness is further reduced.
  • the final cold rolling stage is a significant factor in controlling the earing of the product.
  • the preferred final cold work percentage is that point at which the optimum balance between the yield strength and earing is obtained. This point can be readily determined for a particular alloy composition by plotting each of the yield strength and earing values against the cold work percentage. Once this preferred cold work percentage is determined for the final cold rolling stage, the gauge of the strip during the intermediate annealing stage and, consequently, the cold working percentage for the initial cold roll stage can be determined.
  • the final cold work percentage required to minimize earing is dependent upon the composition of the particular alloy. It is expected that aluminum alloys with higher magnesium content have higher cold-work percentages.
  • the thickness is reduced in the second cold rolling stage by about 35 percent to about 70 percent, preferably by about 45 percent to about 65 percent, and more preferably by about 50 percent to about 60 percent, to a final gauge of, for example, less than about 0.0116 inches (0.29 mm).
  • the second stage can include a single cold rolling pass or can include two or more passes, and the final gauge can be, for example, 0.010 inches (0.254 mm).
  • the second cold rolling stage can preferably include stabilizing the cold rolled strip by employing a water- based rolling emulsion during the cold rolling process.
  • the amount of reduction which is possible during cold rolling utilizing an oil-based emulsion is limited by the flash point of the emulsion. Greater reduction creates greater friction which increases the exit temperature of the strip. If the temperature rises above the flash point of the emulsion, a fire can occur. Consequently, the reduction must be limited such that the heat generated remains below the flash point of the oil-based emulsion.
  • stabilizing during cold rolling by utilizing a water-based rolling emulsion reduces the chance of a fire.
  • the strip can be subjected to a tension leveling step to achieve a more uniform flatness. This is accomplished by pulling or stretching the strip between rollers.
  • the aluminum alloy sheet produced according to the present invention is useful for a number of applications. These applications include, but are not limited to, cable sheathing, Venetian blind stock, and other building products.
  • the alloy sheet produced according to the present invention is particularly useful for drawn and ironed container bodies and for container tops. When the aluminum alloy sheet is to be fabricated into container tops, the intermediate anneal step is preferably not performed.
  • the as-rolled alloy sheet Before baking or stabilization, the as-rolled alloy sheet has a yield strength greater than about 38 ksi (262 MPa) , preferably greater than about 42 ksi (290 MPa) and more preferably greater than about 44 ksi (304 MPa) .
  • the as-rolled alloy sheet preferably has a tensile strength preferably greater than about 46 ksi (318 MPa) and more preferably greater than about 48 ksi (331 MPa) .
  • the aluminum alloy sheet is cut into substantially circular blanks.
  • the blanks are then shaped with a die to form a cup.
  • the cup is drawn and ironed into a container body by forcing the cup through a series of dies having progressively smaller diameters.
  • the container body is typically placed in a drying oven to remove moisture.
  • the drying oven will typically be at a temperature of approximately 400°F (204°C) and the container will typically stay within the oven for about 3.5 minutes.
  • the container can be internally coated and painted on the exterior. After coating and painting, the container is again subjected to baking for about 3.5 minutes at about 400°F (204°C) to cure the paint and the coating.
  • a technique useful for measuring the strength of a container body is to measure the dome strength of the container.
  • the dome strength is the internal pressure that a container can withstand before the dome at the bottom of the container yields, or deforms.
  • the container maintain a yield strength of between about 38 ksi (262 Mpa) and about 42 ksi (290 MPa) after the final baking process described above.
  • the aluminum alloy sheet according to the present invention preferably have a tensile strength greater than about 38 ksi (262 MPa) after baking and more preferably between about 42 ksi (290 MPa) and about 46 ksi (318 MPa) after baking.
  • the alloy sheet according to the present invention preferably has a 45° earing percentage of less than about 2 percent, more preferably less than about 1.8 percent, and most preferably less than about 1.7 percent.
  • T ⁇ is low earing characteristic facilitates the manufacture of drawn and ironed container bodies, reduces the labor required during the drawing and ironing, and minimizes plant scrap.
  • a melt derived from scrap aluminum was adjusted to have a manganese concentration of 1.0 weight percent and a magnesium concentration of 2.8 weight percent.
  • the resulting alloy composition was cast as a strip in a continuous chill block caster through a 16 mm distributor tip. Hot rolling reduced the cast strip to a gauge of 0.085 inches (2.16 mm) with an exit temperature of from 620°F to about 640°F (325°C to 340°C) .
  • the hot rolled strip was subsequently annealed (heat treated) for about three hours at 825°F (440°C) .
  • the first stage included two cold roll passes, the first pass reducing the strip to a gauge of 0.055 inches (1.40 mm) and the second reducing the strip to a gauge of 0.017 inches (0.43 mm) .
  • the cold rolled strip was then intermediate annealed at 650°F to 700°F (340°C to 375°C) and cold rolled in a second stage, comprising a single pass, to a final gauge of 0.0110 inches (0.28 mm).
  • Table 3 illustrates the results of tests showing the effect of increasing the final cold work percentage on ultimate tensile strength (UTS) , yield tensile strength
  • a sheet fabricated from Alloy C in accordance with the process of the present invention with cold work of 55 percent has a tensile strength of about 48.7 ksi (336 MPa), a yield strength of about 46.1 ksi (318 MPa) and a 45° earing percentage of about 1.7 percent.
  • Figure 3 graphically illustrates the effect of changes in the amounts of manganese and magnesium on ultimate tensile strength (UTS) , yield strength and earing percentage in aluminum alloy sheets fabricated in accordance with the present invention.
  • the alloys identified as R-16, R-22 and U-03 are AA 5017 alloys and the alloy identified as C-10 is Alloy A of the present invention (from Table 2 above) .
  • the concentrations of manganese and magnesium in each of the alloys is set forth in Table 4: ei t erce
  • the following example illustrates the high strength of containers fabricated from aluminum sheet of the present invention.
  • Aluminum alloy sheets were produced using Alloy A, having 1.0 weight percent manganese and 2.8 weight percent magnesium, in accordance with the process of the present invention. During the process, some of the sheets were stabilized during cold rolling, while the others were not. The sheets were cold rolled to three gauges and fabricated into two-piece aluminum beverage containers which were then subjected to dome strength testing to measure the maximum internal pressure which a sealed container can withstand. The results are shown in Table 5: TABLE 5
  • containers fabricated from aluminum sheet of the present invention employing the preferred process described hereinabove have sufficient strength to withstand the internal pressures generated by pasteurized beer and other highly carbonated beverages even in thin gauges.
  • a melt derived from scrap aluminum is adjusted to have a manganese concentration of 1.0 weight percent and a magnesium concentration of 2.5 weight percent.
  • the resulting alloy composition is cast as a strip in a continuous chill block caster.
  • Hot rolling reduces the cast strip to a gauge of about 0.085 inches (2.16 mm) with an exit temperature of from 620°F to about 640°F (325°C to 340°C) .
  • the hot rolled strip is subsequently annealed (heat treated) for about three hours at 825°F (440°C) .
  • the percentage of cold work on the hot rolled strip is varied and the results are plotted in Figure 4.
  • the results are plotted against a direct cast alloy having a composition comprising 1.1 percent magnesium and 0.8 percent manganese.
  • a cold work percentage of less than about 62 percent on the alloy of the present invention results in an earing of less than about 1.8 percent.
  • To achieve a 45° earing of less than about 1.8 percent on the direct cast alloy requires a cold work percentage of greater than 80 percent.
  • Example 6 Table 6 lists the manganese and magnesium concentrations for two examples of prior art alloys, and three examples of alloys according to the present invention.
  • Example A is an AA 5017 alloy
  • Example B is an AA 3104 alloy
  • Examples C, D & E are according to the present invention.
  • Table 7 shows the results of block casting these compositions.
  • the block caster produced sheets of 5017 and 3104 alloys that have an after bake yield strength below the 38 ksi minimum required to meet the minimum average 90 psi buckle strength for beverage cans.
  • the Example D alloy exhibits excellent strength, and is useful for manufacturing can bodies.
  • Examples C and E according to the present invention are most preferred since they fall within the desired mechanical property limits after stabilization and baking.
  • the aluminum alloy sheet of the present invention can be fabricated by the use of processes other than the process of the present invention and derived from alloys other than the alloys of the present invention. It is to be expressly understood that such modifications and adaptations are within the spirit and scope of the present invention.

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  • Crystallography & Structural Chemistry (AREA)
  • Metal Rolling (AREA)
  • Containers Having Bodies Formed In One Piece (AREA)
  • Rigid Containers With Two Or More Constituent Elements (AREA)

Abstract

Une feuille d'aluminium est décrite. La bande convient à la fabrication à la fois d'extrémités et de corps de récipients dans des épaisseurs plus faibles que celles qui sont généralement employées, possède des caractéristiques de formation de cornes faibles et peut être obtenue à partir d'aluminium recyclé. Un alliage convenant particulièrement à la fabrication de ladite feuille d'aluminium a de préférence une concentration en magnésium allant d'environ 1,9 à environ 2,8 pour cent en poids et une concentration en manganèse allant d'environ 0,9 à environ 1,6 pour cent en poids. Un procédé convenant particulièrement à la fabrication de ladite feuille d'aluminium consiste de préférence à couler de manière continue en coquille l'alliage en fusion pour former une bande, à laminer la bande à chaud pour obtenir une première épaisseur, à recuire la bande laminée à chaud et ensuite à laminer à froid la bande recuite pour obtenir une épaisseur finale. Le laminage à froid comporte de préférence deux stades séparés par une phase intermédiaire de recuit. Ledit procédé accroît la résistance à la traction et la limite conventionnelle d'élasticité tout en réduisant le pourcentage de formation de cornes, même pour des épaisseurs très faibles, de l'ordre de 0,010 pouce.
PCT/US1991/006374 1990-09-05 1991-09-05 Feuilles en alliage d'aluminium WO1992004476A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
AU87562/91A AU659108B2 (en) 1990-09-05 1991-09-05 Al base - Mg-Mn alloy sheet for manufacturing drawn and ironed container bodies
MX9201202A MX9201202A (es) 1991-09-05 1991-09-05 Material laminado de aleacion de aluminio y procedimiento para producirlo.
NO93930792A NO930792L (no) 1990-09-05 1993-03-04 Tynnplate-aluminiumlegering

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US577,880 1990-09-05
US07/577,880 US5104465A (en) 1989-02-24 1990-09-05 Aluminum alloy sheet stock
US75493091A 1991-09-04 1991-09-04
US754,930 1991-09-04

Publications (1)

Publication Number Publication Date
WO1992004476A1 true WO1992004476A1 (fr) 1992-03-19

Family

ID=27077367

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1991/006374 WO1992004476A1 (fr) 1990-09-05 1991-09-05 Feuilles en alliage d'aluminium

Country Status (5)

Country Link
EP (1) EP0547175A4 (fr)
JP (1) JPH06501057A (fr)
AU (1) AU659108B2 (fr)
CA (1) CA2091187A1 (fr)
WO (1) WO1992004476A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0576171A1 (fr) * 1992-06-23 1993-12-29 KAISER ALUMINUM & CHEMICAL CORPORATION Procédé pour fabriquer une tôle de boîte
WO1997011205A1 (fr) * 1995-09-18 1997-03-27 Kaiser Aluminum & Chemical Corporation Procede de fabrication des feuilles de boites-boisson
WO1998001592A1 (fr) * 1996-07-08 1998-01-15 Alcan International Limited Alliage d'alumminium fondu utilisable comme materiau de fabricaiton de boites metalliques

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0547112A4 (en) * 1990-09-05 1993-09-08 Golden Aluminum Company Process of fabrication of aluminum sheet

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4929285A (en) * 1989-05-04 1990-05-29 Aluminum Company Of America Aluminum sheet product having reduced earing and method of making

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6035424B2 (ja) * 1976-03-03 1985-08-14 三菱アルミニウム株式会社 絞り成形用アルミニウム合金板の製造法
US4238248A (en) * 1978-08-04 1980-12-09 Swiss Aluminium Ltd. Process for preparing low earing aluminum alloy strip on strip casting machine
JPS5943986B2 (ja) * 1980-01-21 1984-10-25 住友軽金属工業株式会社 強度と異方性にすぐれたアルミニウム合金硬質板の製造方法
JPS56158854A (en) * 1980-05-12 1981-12-07 Mitsubishi Alum Co Ltd Manufacture of aluminum alloy sheet for deep drawing with low earing ratio
US4318755A (en) * 1980-12-01 1982-03-09 Alcan Research And Development Limited Aluminum alloy can stock and method of making same
CH657546A5 (de) * 1982-12-16 1986-09-15 Alusuisse Verfahren zum herstellen eines zur fertigung von dosendeckeln geeigneten bandes.
JP2584615B2 (ja) * 1986-02-07 1997-02-26 スカイアルミニウム 株式会社 成形加工用硬質アルミニウム合金圧延板の製造方法
JPS63282246A (ja) * 1987-05-14 1988-11-18 Kobe Steel Ltd 高強度で耐食性、成形性の優れた焼付硬化型包装材用アルミニウム合金薄板及びその製造方法
JP2521330B2 (ja) * 1988-07-12 1996-08-07 株式会社神戸製鋼所 高成形性アルミニウム合金硬質板の製造法
GB8905005D0 (en) * 1989-03-04 1989-04-19 Scapa Group Plc Improvements in or relating to papermakers and like fabrics
WO1992004477A1 (fr) * 1990-09-05 1992-03-19 Golden Aluminum Company Composition d'alliage d'aluminium
EP0547112A4 (en) * 1990-09-05 1993-09-08 Golden Aluminum Company Process of fabrication of aluminum sheet
JPH04221036A (ja) * 1990-12-20 1992-08-11 Sky Alum Co Ltd アルミニウム２ピース缶体およびその製造方法
ES2051258T3 (es) * 1991-03-14 1996-12-01 Pechiney Rhenalu Aleaciones de aluminio para estampacion-estiramiento resistentes, conformables e isotropas.

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4929285A (en) * 1989-05-04 1990-05-29 Aluminum Company Of America Aluminum sheet product having reduced earing and method of making

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP0547175A4 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0576171A1 (fr) * 1992-06-23 1993-12-29 KAISER ALUMINUM & CHEMICAL CORPORATION Procédé pour fabriquer une tôle de boîte
WO1997011205A1 (fr) * 1995-09-18 1997-03-27 Kaiser Aluminum & Chemical Corporation Procede de fabrication des feuilles de boites-boisson
WO1998001592A1 (fr) * 1996-07-08 1998-01-15 Alcan International Limited Alliage d'alumminium fondu utilisable comme materiau de fabricaiton de boites metalliques
GB2333530A (en) * 1996-07-08 1999-07-28 Alcan Int Ltd Cast aluminium alloy for can stock
GB2333530B (en) * 1996-07-08 2000-10-11 Alcan Int Ltd Cast aluminium alloy for can stock

Also Published As

Publication number Publication date
EP0547175A1 (fr) 1993-06-23
CA2091187A1 (fr) 1992-03-06
EP0547175A4 (en) 1993-09-08
AU8756291A (en) 1992-03-30
JPH06501057A (ja) 1994-01-27
AU659108B2 (en) 1995-05-11

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