ALUMINUM ALLOY HARD SHEET HAVING HIGH STRENGTH AND EXCELLENT IN CUP DISTORTION PATTERN AND ITS MANUFACTURE

摘要

PURPOSE: To efficiently suppress a distortion pattern at the time of cup forming and particularly to provide an aluminum alloy hard sheet having high strength and its manufacturing method. ;CONSTITUTION: The objective aluminum alloy hard sheet having high strength of ≥30kgf/mm² tensile strength and excellent in a cup distortion pattern is a one characterized, in an aluminum ally contg. 0.5 to 1.5% Mn, 0.5 to 1.5% Mg and 0.05 to 0.5% Cu, and the balance Al with inevitable impurities, by distributing precipitates of ≥0.2μm per ≤0.5 piece/μm² and precipitates of ≤0.1μm per ≥1 piece/μm². This alloy hard sheet is obtd. by subjecting the ingot of an aluminum alloy having this chemical components to homogenizing heat treatment, finishing hot rolling so as to regulate the final sheet thickness to 1.5 to 3.0mm, executing cold rolling at need, or without executing it, subjecting it to solution heat treatment at 550 to 620°C, then executing precipitating treatment in the temp. range of 150 to 250°C, and furthermore, subjecting it to cold rolling of ≥30%.;COPYRIGHT: (C)1993,JPO&Japio