| 摘要 |
PURPOSE:To provide a rolled Al alloy sheet for forming which is superior in formability, and above all, elongating, bending and flanging properties to the conventional sheet by incorporating respectively prescribed ratios of Si and Mg therein and specifying the max. size of an intermetallic compd. in the matrix to a specific value or below. CONSTITUTION:The melt of the Al alloy contg. by wt%, 0.4%n2.5% Si and 0.1-1.2% Mg is continuously supplied between a pair of rolls cooled from the inside and the sheet solidified to 3-15mm thickness is continuously cast. The solidifying rate in this casting stage is required to be high and the cooling rate thereof is kept at >=100 deg.C/sec. The casting sheet is the subjected to a homogenization treatment at 450-600 deg.C at need, then to cold rolling down to a required thickness. The cold rolled sheet is subjected to a soln. heat treatment and hardening by the conventional method by which the objective rolled Al alloy sheet for forming having <=5mum max. size of the intermetallic compd. in the matrix is obtd.
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