National Steel Corporation

Carmen C Manzonelli

David A Chatfield

Robert G Blossey

Joseph L Tessandori

A method of producing high tensile aluminum-magnesium alloy sheet from an aluminum-based melt containing a relatively low percentage of magnesium, such as 1.5-2.3%, in which the melt is formed into a sheet having a uniform thickness between 1/8-1/2 inch quenched to a temperature below about 500.degree. F. within a period of not more than three (3) minutes, in which the quenched sheet is cold rolled straight down to a thickness between 0.01 and 0.02 inch without the application of extraneous heat to the sheet. The resulting aluminum-magnesium alloy sheet has a fully-hardened tensile strength in excess of 50,000 psi.

Method of producing high tensile aluminum-magnesium alloy sheet and the

In continuous casting of aluminum base alloy in sheet form where the alloy comprises small but effective amounts of silicon, iron, manganese, magnesium and copper, an objectionable amount of edge cracking has occurred in the product. This has necessitated side trimming the sheet with the resultant cost of the edge shearing operation and wasted energy in melting the scrap. Applicants have discovered that by increasing the iron and manganese contents of the alloy and decreasing the silicon and magnesium contents, edge cracking can be eliminated or reduced to the point where edge shearing can be eliminated or significantly reduced.

Method of casting aluminum base alloy sheet and product

Continuously cast aluminum alloy castings are provided which may be cold worked to thin gages without the need for a homogenizing thermal treatment. The castings comprise an aluminum alloy which consists essentially of 0.30-0.50% of copper, 0.35-0.60% of magnesium, up to 0.50% of zinc, residual silicon in an amount up to 0.40%, residual iron in an amount up to 0.70%, residual manganese in an amount up to 0.10%, residual chromium in an amount up to 0.10%, residual sodium in an amount up to 0.0006%, other residual elements in a total amount up to 0.15% and in an amount up to 0.05% for each, and the remainder aluminum. The castings are preferably in the form of continuously cast strip having an initial thickness not greater than about one inch. The strip may be cold rolled in a plurality of cold rolling passes to a final thickness of about 0.001-0.01 inch in the absence of a homogenizing thermal treatment. The strip is annealed at least once intermediate the first and last cold rolling passes at an annealing temperature of 600-800.degree.F. for a period of 1-6 hours. Following the last cold rolling pass, if desired the strip may be given a further anneal at a temperature of about 350-800.degree.F. for about 0.5-10 hours. The resulting semirigid container stock is especially useful in the manufacture of disposable containers.

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Weirton, WV, United States of America

Carmen C Manzonelli