Patent ID: 8372220

Claim:
An aluminum alloy forging comprising an aluminum alloy comprising aluminum and, by mass, Mg: 0.6 to 1.0%, Si: 0.8 to 1.4%, Mn: 0.4 to 1.0%, Fe: 0.05 to 0.35%, Zn: 0.1% or below, Cu: 0.2% or below, Cr: 0.35% or below, Zr: 0.25% or below, Ti: 0.01 to 0.1%, and inevitable impurities, and having a hydrogen gas concentration of 0.25 ml/100 g of Al or below, wherein an area ratio of Mg 2 Si having a maximum length of 0.1 μm or above is 0.15% or below, a recrystallization ratio of the aluminum alloy is 20% or below, and a size distribution index value defined by V/r of dispersed particles of the aluminum alloy, wherein V is an area ratio [%] of dispersed particles, and r is an average radius [nm] of the dispersed particles, is 0.20 or above.