Patent ID: 7927436

Claim:
A method of manufacturing a high-strength aluminum alloy extruded product which exhibits an excellent corrosion resistance comprising the step of: extruding continuously a billet of an aluminum alloy into a solid product by using a solid die, in which a bearing length, L, is 0.5 mm or more and the bearing length and thickness, T, of the solid to be extruded satisfy the relationship L≦5T, to obtain the solid product having a recrystallization cross-section structure with a grain size of no more than 500 μm, wherein a flow guide is provided in front of the solid die, an inner circumferential surface of a guide hole of the flow guide is separated from an outer circumferential surface of an orifice which is continuous with the bearing of the solid die at a distance of 9-15 mm and the thickness of the flow guide is 5-25% of the diameter of the billet, the aluminum alloy comprising, in mass %, 0.6-1.2% Si, 0.8-1.3% Mg, 1.3-2.1% Cu, 0.04-0.35% Cr and no more than 0.05% Mn as an impurity, with the balance being aluminum and unavoidable impurities, and the following (1)-(4) relationships being satisfied, 3%≦Si %+Mg %+Cu %≦4% (1) Mg %≦1.7×Si % (2) Mg %+Si %≦2.7 (3) Cu %/2≦Mg % (Cu %/2)+0.6% (4).