Patent ID: 11572608

Abstract:
An aluminum alloy thick plate is formed of an aluminum alloy including Mg of 2.0 to 5.0 mass %, and has a plate thickness of 300 to 400 mm. A is 700 pieces/cm2 or less and B is 1.3 times or more as large as A, where (i) A (pieces/cm2) is a maximum value in numbers of crystallized products with a maximum length of 60 μm or more per unit area in each of positions located at a center portion in a thickness direction and at positions of 0.39 Wa to 0.48 Wa in a plate width direction; and (ii) B (pieces/cm2) is a maximum value in numbers of crystallized products with a maximum length of 60 μm or more per unit area in each of positions located at the center portion in the thickness direction and at positions of 0.12 Wa to 0.30 Wa in the plate width direction.