ALUMINUM ALLOY SHEET EXCELLENT IN SURFACE QUALITY AFTER ANODIC OXIDATION TREATMENT AND PRODUCTION METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To provide an aluminum alloy sheet which is free from belt-like stripe pattern after being subjected to anodic oxidation treatment and is consequently excellent in surface quality after the anodic oxidation treatment.SOLUTION: There is provided the aluminum alloy sheet which is an 5000 series aluminum alloy sheet containing 1.0 to 6.0 mass% of Mg. The content of Mg in a solid-solution state on the outermost surface of the aluminum alloy sheet changes as a belt with a width of 0.05 mm or more in a width direction of the aluminum alloy sheet and difference of concentration between adjoining belts is 0.20 mass% or less.