Production manner and the aluminum alloy board and aluminum alloy board formation item null of the aluminum alloy board where the streak pattern is not generated by the alkali extraction before the anodic oxidation

摘要

PROBLEM TO BE SOLVED: To produce, with high productivity, an aluminum alloy sheet free from occurrence of striped pattern at the surface to be treated even if alkali treatment is applied. ;SOLUTION: An aluminum alloy ingot, having a composition consisting of, by weight, 0.40-1.5% Fe, 0.03-0.30% Si, 0.004-0.20% Cu, 0.01-0.05% Ti, 0.0001 0.02% B, and the balance aluminum with inevitable impurities, is subjected to homogenizing treatment at 350 to 430°C, and successively, hot rolling by plural pases is applied to this ingot to form a hot rolled plate. At this time, hot rolling is started at a temperature not exceeding the finishing temperature of homogenizing treatment, and hot rolling is performed without causing recrystallization before the final pass among the plural passes and at least the surface layer of the hot rolled plate is recrystallized by the final pass alone to form a recrystallized structure having 50 μm average recrystallized grain size in a direction perpendciualr to rolling direction. Then, cold rolling is applied to the hot rolled plate.;COPYRIGHT: (C)1999,JPO