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

Definitions

• the invention relates to a process for the production of aluminum rolled products with iron as the predominant alloying element, which after final annealing, after annealing at at least 250 ° C., has a grain size of less than 10 ⁇ m.
• Gram size means the average diameter of all grains present.
• Such small grains in the annealed condition are, among other things, a good prerequisite for high strength or yield strength with good ductility at the same time; this applies to all thickness ranges from the mm sheet to the film of a few ⁇ m thickness.
• the invention is therefore based on the object of providing a process based on low-alloy aluminum-iron alloys which, using the semi-continuous ingot continuous casting plants which are in widespread use, permits the production of rolled products in which, with a final roll thickness, after annealing above 250 ° C, the grains are smaller than 10 ⁇ m.
• the object is achieved in that an alloy consisting of 0.8 to 1.5 wt.% Iron, each up to 0.5% silicon and manganese, the sum of silicon and manganese being between 0.2 and 0.8%, and other components up to 0.3% each, up to 0.8% in total, the rest aluminum, is cast at a solidification rate of 2.5 to 25 cm / min, after hot rolling at a cooling rate of at least 0.5 K / sec to temperatures below 120 ° C and then up to a Thickness reduction of at least 75% is cold rolled without intermediate annealing, and that the annealing temperature at final thickness does not exceed 380 ° C.
• the specified method is less suitable for solidification speeds outside the defined range.
• the ratio of deformability to strength can be increased as the final annealing temperature increases. It was found for the alloy range according to the invention that the final annealing temperature must not exceed 380 ° C. in order to avoid grains of more than 10 pm with certainty.
• the steps following hot rolling are also critical for the production of fine grains.
• the tests showed that, in order not to endanger the formation of fine grains, the cooling rate in the area between the hot rolling end temperature and about 120 ° C must not fall below 0.5 K / sec; the cooling rate below 120 ° C is insignificant in this regard.
• Such cooling rates can be achieved when the strip passes through a water tank or when the strip is cooled by means of intensive air flow.
• the first annealing after hot rolling, a final annealing or intermediate annealing, if necessary, must not take place at a thickness which is more than a quarter of the final hot rolling thickness.
• the weight fraction of iron must be higher than 0.8%; otherwise grains of more than 10 ⁇ m in size are formed after the final annealing. On the other hand, if there is more than 1.5% iron, the eutectic composition is approached; this harbors the risk of forming coarse precipitates during casting, which would seriously impair the deformability.
• ingots of both alloys with a cross section of 412 x 1000 mm are cast at a speed of 10 cm / min; the rate of solidification was 7 cm / min.
• the ingots were milled over, preheated to 540 ° C and hot-rolled to 8 mm.
• the hot rolled strip passed through a water box and was cold rolled to 0.7 mm.
• a 3-hour annealing was carried out at 350 ° C; then cold rolling to 0.1 mm. After 20 hours of final annealing at 320 ° C the following values were achieved: (the mechanical values measured in the rolling direction)
• Example 2 Up to 0.1 mm, the two alloys were processed in the same way as in Example 1. It was then cold rolled to 13 ⁇ m and finally annealed at 280 ° C.
• the manufacturing procedure corresponds in one case (AE) to that of Example 1, in the other case (AK) it was changed so that the hot rolled strip was not passed through a water box, but was immediately rewound.
• Example 1 Up to 0.1 mm the above-mentioned alloy was processed as in Example 1. The 20-hour final annealing was carried out in one variant (GE) at 320 ° C and in another variant (GK) at 400 ° C.
• Example 5 Influence of the degree of cold rolling between the hot rolling thickness and the thickness during the first annealing
• Alloy E 1 was processed as in Example 1 to and with the water cooling of the hot-rolled strip.
• the strip was further cold-rolled to 2.8 mm, annealed at 360 ° C for 3 hours, further rolled to 0.8 mm, annealed at 350 ° C for 3 hours, finish-rolled to 0.1 mm and finally, as in Example 1, annealed at 320 ° C for 20 hours ( KW).

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• Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• Thermal Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Physics & Mathematics (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Metal Rolling (AREA)
• Heat Treatment Of Sheet Steel (AREA)
• Forging (AREA)
• Cereal-Derived Products (AREA)

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• 1983
  • 1983-08-23 CH CH4584/83A patent/CH654027A5/de not_active IP Right Cessation
  • 1983-08-26 DE DE3330814A patent/DE3330814C2/de not_active Expired
  • 1983-09-30 US US06/537,942 patent/US4483719A/en not_active Expired - Fee Related
• 1984
  • 1984-07-24 AT AT84810363T patent/ATE29742T1/de not_active IP Right Cessation
  • 1984-07-24 DE DE8484810363T patent/DE3466247D1/de not_active Expired
  • 1984-07-24 EP EP84810363A patent/EP0140827B1/fr not_active Expired
  • 1984-08-21 NO NO84843337A patent/NO162081C/no unknown

Patent Citations (3)

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