Al-Mg-Si-BASED ALUMINUM ALLOY HOLLOW EXTRUSION MATERIAL AND MANUFACTURING METHOD THEREFOR

摘要

To provide an Al-Mg-Si-based alloy hollow extrusion material excellent in flexure crushability and corrosion resistance and having high strength.SOLUTION: There is provided an aluminum alloy hollow extrusion material containing Si:0.80 to 1.25 mass%, Mg:0.65 to 1.20 mass%, Fe:0.15 to 0.30 mass%, Mn:0.40 to 0.80 mass%, Cu:0.01 to 0.60 mass%, Cr:0.09 to 0.21 mass%, Ti:0.01 to 0.10 mass% with Zr percentage content of 0.05 mass% or less and the balance Al with inevitable impurities, satisfying a relational expression of both of 0.90≥α-(β/1.73)≥0.19 and 1.90≥β+(β/1.73)≥1.00, where Si percentage content in the alloy is α (mass%) and Mg percentage content in the alloy is β (mass%), in which a metallic structure of a cross section of the extrusion material has a fibrous structure, percentage of area of the fibrous structure in whole area of the cross section is 80% or more, 0.2% bearing force of the hollow extrusion material is 330 MPa or more and limit flexure of the extrusion material R is 5 mm or less.SELECTED DRAWING: Figure 1