| 摘要 |
A high-strength aluminum material having a chemical composition which includes Zn: more than 7.2% (mass %, the same applies hereafter) and 8.7% or less, Mg: 1.3% or more and 2.1% or less, Cu: less than 0.50%, Fe: 0.30% or less, Si: 0.30% or less, Mn: less than 0.05%, Cr: 0.20% or less; Zr: less than 0.05%, Ti: 0.001% or more and 0.05% or less, the balance being Al and unavoidable impurities, is provided. It has a proof stress of 350 MPa or more, and a metallographic structure formed of a recrystallized structure. The recrystallized structure is comprised of crystal grains having an average particle diameter of 500μm or less, and a crystal grain length in a direction parallel to a hot working direction is 0.5 to 4 times as long as a crystal grain length in a direction perpendicular to the hot working direction. |
