| 摘要 |
PURPOSE:To manufacture the Al alloy sheet for superplastic working having excellent corrosion resistance and strength by subjecting an alloy having specified compsn. constituted of Mg, Mn, Cr, Zr, V and Al to continuous casting into a specified plate thickness and thereafter executing specified homogenizing treatment and cold rolling. CONSTITUTION:The molten metal of an Al alloy contg., by weight, 0.5 to 3.8% Mg, furthermore contg. one or more kinds among 0.8 to 3.5% Mn, 0.1 to 0.5% Cr, 0.1 to 0.4% Zr and 0.1 to 0.4% V and the balance substantial Al with inevitable impurities is subjected to continuous casting into a plate having 3 to 15mm thickness. The continuously cast plate is immediately, or after cold-rolled, subjected to homogenizing treatment of holding under heating at 450 to 630 deg.C for 30min 20hr. The alloy plate is thereafter subjected to cold rolling at >=30% rolling reduction. If required, the cold rolled sheet is furthermore subjected to final annealing of heating to 400 to 600 deg.C at >=1 deg.C/sec temp. rising rate. In this way, the Al alloy rolled sheet for superplastic working contg. <=7mum maximum size of intermetallic compounds in the matrix, having excellent corrosion resistance obtainable of high strength without being subjected to heat treatment after plastic working and shownable of excellent superplastic characteristics can be obtd. |
