Classifications

• • 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
• • 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
• • 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
• • 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
  • C22C21/08—Alloys based on aluminium with magnesium as the next major constituent with silicon

Definitions

• ABSTRACT OF THE DISCLOSURE A process for the production of a strip of a manganesecontaining aluminum alloy which yields a fine grained product with mechanical properties which make the strip of outstanding value for formability, especially for deepdrawing.
• the process comprises homogenising a cast billet of the alloy at a temperature over 560 C., hot-rolling, cold-rolling and annealing the cold-rolled strip in two stages, first at a temperature below the temperature of complete recrystallization at least during five hours and in the second stage above that temperature.
• This invention relates to the production of strip of manganese-containing aluminum alloys.
• strip is used for the production of seamless deep-drawn containers of aluminum foil because these alloys have a capacity for elongation and fine grain size which make them of outstanding value for forrnability and particularly for deepdrawing.
• Normally deep-drawn containers of aluminum foil are made from strip of 0.05 to 0.3 mm. thick, and generally 0.1 mm. thick, and the strip should have a tensile strength of from to 13 kg./mm. an extension greater than 20%, an Erichsen depth of at least 7.5 mm., and more than 2000 grains per mm.
• a cast billet of the alloy is homogenised at a temperature above 560 C., hot-rolled to strip, cold-rolled and then, while it is in the condition resulting from cold-rolling, is annealed in two stages, in the first of which it is held for at least five hours in the temperature range of C. up to just beneath the temperature of complete recrystallization, and in the second of which it is heated above that temperature.
• the strip is heated in the first stage for at least ten hours in the temperature range of 200 C. to a temperature just beneath the temperature of complete recrystallization.
• the temperatures referred to in this specification are those that the metal attains.
• the process according to the invention enables the use of a usual batch furnace for the annealing and nevertheless gives fine-grained strips which also have the necessary properties for the production of seamless containers.
• the initial temperature of the hot-rolling is above 500 C.
• this initial temperature it is preferred to make this initial temperature from 400 to 480 C. This lower hot-rolling temperature in combination with the other features of the process according to the invention brings about further improvement of the properties of the strip.
• Intermediate annealing may be effected during the cold: rolling, but preferably there is no such intermediate annealing, and in any case it is essential that at the beginning of the annealing after the cold-rolling the strip should be in the state resulting from at least 60% cold-work.
• the temperature range from 160 C. to a temperature just below that of complete recrystallization may be traversed in the prescribed time at a slow rate of heating, but preferably the heating takes place more or less quickly up to a temperature just below the temperature of complete recrystallization, and this temperature is maintained for at least five hours before the second stage of heating above the temperature of complete recrystallization begins. It is, of course, desirable that the two stages should be continuous, but the strip can be allowed to cool down between them.
• the two-stage annealing is easy to carry through and makes economic use of a batch oven in a rolling mill.
• the recrystallization temperature depends on the composition of the alloy and its pre-treatment before annealing and can be determined by tests. As is Well known the so-called recrystallization temperature is in fact a temperature range, at the lower end of which the recrystallization begins and only at the upper end of which is recrystallization complete. In the present invention the temperature reached in the first annealing stage may advantageously lie within the range of recrystallized at the end of this stage.
• the invention can be applied to alloys of various compositions, being particularly applicable to those known as AlMn alloys, which usually contain up to 2% manganese, and which may also contain other metals in small amounts, such as iron, magnesium, copper and so forth.
• AlMn alloys which usually contain up to 2% manganese, and which may also contain other metals in small amounts, such as iron, magnesium, copper and so forth.
• magnesium in an amount above 0.1% is advantageous in producing a fine grain in the annealed strip, the magnesium-containing alloys have bad lacquer adhesion and high cold strength, which renders the cold rolling difficult.
• an AlMn alloy with less than 0.1% magnesium is used, and particularly an alloy containing from 0.5 to 1.6% manganese, from 0.1 to 0.6% silicon, from 0.2 to 0.8% iron and from 0 to 0.3%
• the invention may also be applied to other manganese-containing aluminum alloys, and specifically to AlMgMn alloys containing from 0.3 to 1.3% manganese, 0.3 to 5.0% magnesium, 0.1 to 0.6% silicon, 0.2 to 0.8% iron and to 0.3 copper, the balance being aluminum; to
• AlMgSi (Mn) alloys containing from 0.6 to 1.4% magnesium, 0.2 to 1.6% silicon, 0.1 to 1.0% manganese, 0.2 to 0.8% iron and 0 to 0.3% copper, the balance being aluminum; and to AlCuMg(Mn) alloys containing from 0.2 to 1.2% magnesium, 0.1 to 0.6% silicon, 0.1 to 0.5% manganese, 0.2 to 0.8% iron and 1.8 to 3.0% copper, the balance being aluminum.
• Treatment 1 The billet was hot-rolled at a temperature of 550 C. and the strip was annealed in a batch furnace, attaining a temperature of 370 to 400 C. in five hours, which was above the recrystallization temperature.
• Treatment 2 More of the same cold-rolled strip that was used in Treatment 1 was heated to a temperature of 370 to 400 C. by passage through a continuous annealing furnace in the course of a few seconds.
• the initial hot-rolling temperature of the billet was 420 to 430 C.
• the strip was heated through the temperature range of 200 to 340 C. in a period of somewhat more than hours, and in the second stage it was heated to 390 C.
• the initial hot-rolling temperature of the billet was 550 C.
• the strip was held at 330 C. for 20 hours
• the strip was held for 5 hours at a temperature within the range of 350 to 380 C.
• Treatment 5 The initial hot-rolling temperature of the billet was 450 C., and the annealing was effected as in Treatment 4.
• Treatment 6 The initial hot-rolling temperature was again 450 C., and the annealing was effected as in Treatment 4. However in the course of the cold-rolling the strip when reduced to a thickness of 0.5 mm. was subjected to intermediate annealing for 5 hours at 380 C.
• the annealed strips were all tested. In each case the tensile strength and the extension of parallel-sided strips mm. wide over a test length of 180 mm., the Erichsen depth according to DIN 50 101 and the number of grains per mm. after a Barker oxidation by comparison with a standard grain table (Kostron Table, 500 times magnification).
• a process for the production of strip of a manganese-containing aluminum alloy which comprises homogenising a cast billet of the alloy at a temperature over 560 C., hot rolling the billet to strip, cold-rolling the strip and, while it is in the condition resulting from more than 60% reduction by cold-rolling, annealing it in two stages, in the first of which it is held for at least five hours in the temperature range of from 160 C. to just below the temperature of complete recrystallization, and in the second of which it is heated above the recrystallization temperature.
• a process according to claim 1 applied to an alloy containing from 0.3 to 1.3% manganese, 0.3 to 5.0% magnesium, 0.1 to 0.6% silicon, 0.2 to 0.8% iron and 0 to 0.3% copper, the remainder being aluminum.
• a process according to claim 1 applied to an alloy containing from 0.6 to 1.4% magnesium, 0.2 to 1.6% silicon, 0.1 to 1.0% manganese, 0.2 to 0.8% iron and 0 to 0.3% copper, the remainder being aluminum.
• a process according to claim 1 applied to an alloy containing from 0.2 to 1.2% magnesium, 0.1 to 0.6% silicon, 0.1 to 0.05% manganese, 0.2 to 0.8% iron and 1.8 to 3.0% copper, the remainder being aluminum.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Manufacturing Of Steel Electrode Plates (AREA)
• Heat Treatment Of Sheet Steel (AREA)
• Metal Rolling (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=4432589

Family Applications (1)

Country Status (10)

Cited By (13)

Families Citing this family (14)

• 1967
  • 1967-12-29 CH CH1837867A patent/CH493642A/de not_active IP Right Cessation
• 1968
  • 1968-12-13 BE BE725415D patent/BE725415A/xx unknown
  • 1968-12-16 FR FR1595159D patent/FR1595159A/fr not_active Expired
  • 1968-12-16 DK DK614068A patent/DK143203C/da active
  • 1968-12-18 AT AT1232268A patent/AT282983B/de active
  • 1968-12-18 NL NLAANVRAGE6818172,A patent/NL168884C/xx not_active IP Right Cessation
  • 1968-12-20 SE SE17664/68A patent/SE345696B/xx unknown
  • 1968-12-24 US US786749A patent/US3563815A/en not_active Expired - Lifetime
  • 1968-12-27 DE DE1817243A patent/DE1817243C3/de not_active Expired
  • 1968-12-30 GB GB1231090D patent/GB1231090A/en not_active Expired

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