Metal treatment – Process of modifying or maintaining internal physical... – With casting or solidifying from melt
Patent
1995-04-24
1997-04-01
Wyszomierski, George
Metal treatment
Process of modifying or maintaining internal physical...
With casting or solidifying from melt
148552, 148695, C22F 104
Patent
active
056161905
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL SPHERE OF THE INVENTION
The present invention relates to a process for producing, by continuous casting between rolls, a thin sheet of aluminium alloy suitable for making up constituent elements or drinks cans or cans for use with foods.
It is known, for example, to produce lids intended to be combined impermeably with can bodies and thus to form packagings for foods in the liquid or solid state.
These lids are obtained by cutting from a sheet of aluminium alloy discs which may be equipped with opening devices fixed either by riveting or by adhesion.
In order to be able to carry out these mechanical operations and to withstand the stresses resulting from handling and from the pressures exerted inside the cans by certain foods such as carbonated drinks, said sheets have to have a suitable deformation capacity and an adequate yield stress.
Furthermore, as these sheets have to resist the corrosive effects of the atmosphere and of the products contained, it is essential to cover them with protective agents such as lacquers, for example, meaning that said sheets have to be adhesive toward said coatings.
STATE OF THE ART
The German document DE 3247698 (Alusuisse) discloses a process for producing a strip intended for making up can lids from aluminium alloy issuing from a continuous casting machine, characterised in that an alloy containing, by weight, 0.15 to 0.50% of Si, 0.3 to 0.8% of Fc, 0.05 to 0.25% of Cu, 0.5 to 1% of Mn, 2.5 to 3.5% of Mg and up to 0.20% of Ti is cast between two cooled casting rolls forming a casting gap of 5 to 10 mm and in that the resultant strip is cold-rolled to a final thickness of 0.4 to 0.2 mm.
According to this process, to achieve a yield stress of 321 MPa and an elongation of 7.7%, it is necessary, after rolling of the cast strip to a thickness of 1.9 mm, to carry out intermediate annealing involving heating the strip to 380.degree. C. and keeping it at this temperature for 2 hours, then also carrying out final softening annealing by heating to 205.degree. for 8 minutes prior to lacquering.
Therefore, in addition to the energy required to pass from a thickness e1=6.5 mm to a thickness e2=0.3 mm, according to the example, this reduction corresponding to a rolling ratio of (e1-e2)/e1.times.100=95.4%, this process also involves two heating operations at two different stages of rolling.
The document JP 04276047 (Sky Aluminium) describes a process for obtaining hard plates of aluminium alloy with a view to making up can lids, the process involving casting in a thin strip to a thickness of less than 15 mm at a cooling rate higher than 50.degree. C./sec; the plate obtained is subjected immediately or after cold-rolling to a first intermediate annealing treatment, to cold-rolling with a reduction ratio of 30 to 85%, to the second intermediate annealing treatment and finally to final cold-rolling with a reduction ratio higher than 30%, this final cold-rolling optionally being followed by a final annealing treatment.
The alloy has the following composition: 0.5%, the remainder being Al.
A 6 mm thick plate having a yield stress at 45.degree. to the direction of rolling of 305 to 310 N/mm.sup.2 was obtained by this process.
The document EP 99739 (Continental) describes a process for obtaining an aluminium alloy strip suitable for drawing and ironing, for example with a view to obtaining cans. It involves the continuous casting of a strip having a thickness of less 2.54 cm, preferably between 6 and 12 mm, heating to 510.degree. to 620.degree. followed by cold-rolling with reduction in thickness by at least 25%, annealing, a second cold-rolling treatment with reduction of thickness by at least 10%, recrystallization heating and final cold-rolling.
12.1 mm thick strips of different compositions were obtained and treated by the described process; the final products obtained having the following characteristics (table XIX)
The document U.S. Pat. No. 4,411,707 (Coors) describes a process for obtaining strips suitable for the production of lids. It involves the continuous casting of
REFERENCES:
patent: 4435213 (1984-03-01), Hildeman et al.
patent: 5186235 (1993-02-01), Ward
patent: 5306359 (1994-04-01), Eppeland et al.
patent: 5470405 (1995-11-01), Wyatt-Mair et al.
patent: 5531840 (1996-07-01), Uesugi et al.
Legresy Jean-Marc
Raynaud Guy-Michel
Pechiney Rhenalu
Wyszomierski George
LandOfFree
Process for producing a thin sheet suitable for making up consti does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for producing a thin sheet suitable for making up consti, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for producing a thin sheet suitable for making up consti will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-535906