| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an Al-Mg based alloy plate having little generation of SS (stretcher-strain) mark and excellent press formability. <P>SOLUTION: When manufacturing the specific Al-Mg based aluminum alloy plate composed of the composition containing Mg and Zn, a cooling speed in a quenching-treatment time after solution heat treatment is controlled in stages, thereby a positron annihilation life value measured by the positron annihilation method is made to be equal to or lower than a specific value, a freezing vacancy concentration is low and Mg is difficult to diffuse, so that the generation of the SS mark upon press-forming is restrained thanks to the plate structure to be difficult to generate the serration (vibration). <P>COPYRIGHT: (C)2012,JPO&INPIT |
