| 摘要 |
PROBLEM TO BE SOLVED: To provide an Al-Mg-based aluminum alloy sheet suitable for a wide mouthed cap. SOLUTION: The aluminum alloy sheet for a wide mouthed bottle can cap has a chemical composition comprising 1.2 to 2.1% Mg, and the balance aluminum with inevitable impurities and has a sheet thickness of 0.2 to 0.3 mm. The tensile strength of the original sheet is 160 to 230 MPa, and the proof stress is 110 to 210 MPa. The tensile strength of the baked sheet obtained by subjecting the original sheet to heat treatment so as to be held at 200°C for 10 min is 160 to 230 MPa, the proof stress is 100 to 200 MPa, the elongation is≥5%, and the average crystal grain size in the sheet surface is≤50μm. It is preferable that, in earings generated at the opening part of a drawn cup in the original sheet or the baked sheet, the earing ratio of earing generated at the four places in the 45°directions to the rolling direction or the four places in the 0°, 90°, 180°and 270°directions is≤2.0%, and also, the earing ratio of earing generated at the two places in the 0°and 180°directions to the rolling direction is≤2.0%. COPYRIGHT: (C)2005,JPO&NCIPI
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