Production method for aluminum alloy ingot, continuously cast aluminum alloy rod, and forged aluminum alloy product

1:

• A method for producing an aluminum alloy ingot containing additive elements of Cu in a range of 0.30 mass % or more and 1.0 mass % or less, Mg in a range of 0.80 mass % or more and 1.8 mass % or less, Si in a range of 0.90 mass % or more and 1.9 mass % or less, Mn in a range of 0.30 mass % or more and 1.2 mass % or less, Fe in a range of 0.20 mass % or more and 0.65 mass % or less, Zn in a range of 0.25 mass % or less, Cr in a range of 0.050 mass % or more and 0.30 mass % or less, Ti in a range of 0.01 mass % or more and 0.1 mass % or less, B in a range of 0.0010 mass % or more and 0.030 mass % or less, and Zr in a range of 0.0010 mass % or more and 0.050 mass % or less, with the remainder being made up of Al and unavoidable impurities, the method comprising:
• a primary melting step in which raw materials containing aluminum alloy scraps with a Si content of 0.60 mass % or more and 0.90 mass % or less and the contents of the other additive elements within the same formulation ranges as those of the aluminum alloy ingot are melted to obtain a first molten metal;
• a primary casting step in which the first molten metal obtained in the primary melting step is solidified into an ingot, and a cooling rate from a liquid-phase temperature to a solid-phase temperature at the final solidification part of the ingot is 10° C./sec or more;
• and
• a secondary melting step in which metallic Si or a Si-containing alloy is added to a molten metal obtained by melting the ingot obtained in the primary casting step, and the Si content is adjusted to be within a range of 0.90 mass % or more and 1.9% mass % or less.