Cooking utensil made from aluminum alloy strips produced by continuous thin gauge twin roll casting

Abstract

The invention concerns a method for making aluminium alloy strips containing (by weight) at least 0.15 to 1.5% Fe and / or 0.35 to 1.9% Mn, with Fe+Mn<2.5% and optionally Si<0.8%, Mg<0.2%, Cu<0.2%, Cr<0.2%, Zn<0.2%, and other elements each <0.1% and <0.3 % in all, by continuous casting between two cylinders cooled and shrinked to a thickness ranging between 1 and 5 mm, the force applied to the cylinders during casting, expressed in tonnes per meter of strip width, being less than 300+2000 / e, e being the cast strip thickness in mm. The invention also concerns strips in alloy of the same composition, twin-roll cast between 1 and 5 mm thick and having a product R0.2 (MPa)xA (%) greater than 2500, and preferably than 3000.

Description

[0001] The invention concerns a method for making aluminium alloy strips with low magnesium and copper content, especially AlFeSi and AlMn alloys, by continuous thin gauge twin-roll casting (<5 mm). It also relates to strips of said alloys cast by thin gauge twin-roll casting, and optionally cold rolled, having high mechanical resistance, good formability and good anisotropy.STATE OF THE ART[0002] To obtain high mechanical resistance with aluminium alloys not requiring subsequent structural hardening, recourse is generally made to the addition of magnesium, as for the alloys of the 5000 series as per the Aluminium Association nomenclature. Aside from the fact that the casting of these alloys, in particular their continuous casting, is fairly demanding, there are applications for which the presence of magnesium in substantial quantities is unacceptable. This is the case for example with sheets intended for enamelled cooking utensils, in which magnesium has an adverse affect on the...

AI Technical Summary

Benefits of technology

0013] The purpose of the invention is to obtain aluminium alloy strips with low Mg and Cu content which, at the as-cast state or at the cold rolled state, offer mechanical resistance which is distinctly greater than that of similar strips having the same composition obtained by conventional casting or thick-gauge continuous casting, and which also have at least equ

Problems solved by technology

Aside from the fact that the casting of these alloys, in particular their continuous casting, is fairly demanding, there are applications for which the presence of magnesium in substantial quantities is unacceptable.

This is the case for example with sheets intended for enamelled cooking utensils, in which magnesium has an adverse affect on the adherence of the enamel layer, or for strips intended for manufacturing heat exchanger blades brazed with a fluoride flux, since the magnesium diffuses on the surface and reacts with the flux.

This kind of composition may prove to be restrictive for some applications in which lesser content alloys are used such as 1050 or copper-free alloys.

The very unusual chromium and zirconium contents, especially when combined with an addition of magnesium, lead to high mechanical resistance but to the detriment of elongation which remains less than 10%, making these alloys unfit, even in the absence of magnesium, for the production of cooking utensils for example.

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