Production mannered null mass of the aluminum alloy board which is superior in rijingumaku Characteristic

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing an aluminum alloy sheet of 6,000 series, which is prevented from causing a ridging mark when being press-formed, even in a mass production hot-rolling line.;SOLUTION: This aluminum alloy comprises 0.4-1.3% Si, 0.2-1.2% Mg, 0.01-0.65% Mn, 0.001-1.0% Cu and the balance Al with avoidable impurities. The manufacturing method comprises the steps of: preparing a large-scale aluminum alloy ingot having the above composition and a thickness of 400 mm or larger; heat-treating the ingot at 500°C or higher but lower than the melting point for homogenization; cooling the ingot at a cooling rate of 50°C/hr to 100°C/hr; then, hot-rolling the slab by rough-rolling the slab at a starting temperature of 350 to 450°C and finish-rolling the plate at a finishing temperature of 350°C or lower, with the use of a hot-rolling line which is composed of a reverse-type roughing mill and a tandem-type finishing rolling mill, and can roll a slab in several ways each comprising a plurality of paths; further cold-rolling the plate; and then solution-treating and quenching the sheet.;COPYRIGHT: (C)2007,JPO&INPIT