| 摘要 |
<p>High strength aluminum alloy sheet having superior surface roughening and formability suitable for home electrical appliances and automobile outer panels and other structural materials and a method of production of the same are provided. High strength aluminum alloy sheet having a chemical composition containing Mg: 2.0 to 3.3 mass%, Mn: 0.1 to 0.5 mass%, and Fe: 0.2 to 1.0 mass%, having a balance of unavoidable impurities and Al, and having an Si among the unavoidable impurities of less than 0.20 mass% and having an average circle equivalent diameter of intermetallic compounds of 1 µm or less, having an area ratio of intermetallic compounds of 1.2% or more, having an average diameter of recrystallized grains of 10 µm or less, and having a tensile strength of 220 MPa or more. This is obtained by pouring an aluminum alloy melt having the above chemical composition in a twin belt caster, continuously casting a thin slab of a thickness of 6 to 15 mm at a cooling rate at a position of 1/4 the slab thickness of 50 to 200°C/sec and winding it up into a coil, then cold rolling it at a cold reduction of 60 to 98%, final annealing it by a continuous annealing furnace at a heating rate of 100°C/min or more, at a holding temperature of 400 to 520°C for a holding time of within 5 minutes.</p> |
