ALUMINUM ALLOY SHEET EXCELLENT IN BAKING HARDENABILITY OF COATING MATERIAL AND PRESS FORMABILITY AND ITS PRODUCTION

摘要

PURPOSE: To provide an aluminum alloy sheet excellent in press formability and excellent in hardenability by low temp. baking and suitable for an automobile body sheet and its manufacturing method. ;CONSTITUTION: This is an aluminum alloy sheet contg., by weight, 0.4 to 1.5% Mg, 0.24 to 1.6% Si, 0.12 to 1.5% Cu, ≤1.0% Zn, 0.005 to 0.15% Ti and ≤0.25% Fe, in which Si and Mg safisfy the relationship of Si ≥0.6Mg (%) and the balance Al with inevitable impurities, in which the average aspect ratio H/L of the crystalline grains is regulated to ≥0.7 and having ≥20μm average grain size and is a manufacturing method for the above alloy sheet in which an aluminum ally ingot having the above compsn. is subjected to homogenizing treatment at 450 to 580°C, is thereafter subjected to hot rolling and cold rolling into a desired sheet thickness, is heated to the range of 480 to 580°C at ≥3°C/sec heating rate, is held for ≤120sec and is cooled to 100°C at ≥2°C/sec cooling rate.;COPYRIGHT: (C)1993,JPO&Japio