Production manner null of 6000 based aluminum alloy extrusive materials which are superior in size

摘要

PROBLEM TO BE SOLVED: To obtain an aluminum alloy extruded material having high strength and excellent in dimensional accuracy. ;SOLUTION: A billet, having a composition which consists of 0.6-1.0% Mg, 0.5-0.8% Si, 0.1-0.3% Fe, 0.005-0.05% Ti, 0.001-0.01% B, ≤0.4% Cu, one or ≥2 kinds among 0.2% Mn, 0.1% Cr, and 0.1% Zr under the condition of Mn+Cr+Zr3%, and the balance essentially Al and in which the excess Si computed from (excess Si)=(Si%-0.58×Mg%) is regulated to 0.1-0.4%, is used. This billet is extruded so that the temp. immediately after extrusion becomes 510-570°C. The resultant extruded material is cooled at a rate of (30 to 150)°C/min until 420°C is reached. Subsequently, the extruded material is cooled through the temp. region from 420 to 280°C at a rate of ≥150°C/min and then cooled through the temp. region from 280 to 150°C at a rate of ≥30°C/min. The resultant extruded material is subjected to aging treatment at 160 to 210°C for 1 to 15 hr.;COPYRIGHT: (C)1998,JPO