摘要 |
An aluminum alloy sheet for high-speed high-temperature blow forming has an aluminum alloy containing 4 to 5% of Mg, 0.35 to 0.5% of Mn and 0.001 to 0.05% of Cr, 0.6% or less of Si+Fe, 0.15% or less of Cu, and the balance being substantially Al. The aluminum alloy sheet has an elongation of 150% or more in a high-temperature tensile test at 400 to 550° C. and at a strain rate of 10<SUP>-2</SUP>/second or more, has a cavitation area percentage of 2% or less at the time of 100% tensile deformation, and is free from any abnormally grown grains of 100 microns or more. A formed piece of the aluminum alloy sheet also has a cavitation area percentage of 2% or less when blow-formed at 400 to 550° C. and at a reduction in sheet thickness of 65% or less, and is free from any abnormally grown grains of 100 microns or more.
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