Aluminum alloy sheet for forming

Abstract

The present invention pertains to an Al—Mg—Si alloy sheet for forming, that contains 0.2-2.0% of Mg, 0.3-2.0% of Si, and 0.005-0.3% of Si (all amounts given with respect to mass), the balance comprising Al and unavoidable impurities, wherein the aluminum alloy sheet for forming is characterized in that the structure of the aluminum alloy sheet is such that the average number density of compounds having a circle-equivalent diameter within a range of 0.3-20 μm as measured by SEM at 500 times magnification is more than 0/mm 2 but not more than 5,000/mm 2 , and of the compounds measured by SEM, the average count ratio of compounds that contain 0.5% by mass or more of Sn as identified using an X-ray spectrograph, is 0% or more but less than 50%. This aluminum alloy sheet for forming exhibits high BH response and good formability.

1 . An aluminum alloy sheet for forming, which is an Al—Mg —Si alloy sheet comprising, in terms of mass %:
 0.2-2.0% of Mg; 
 0.3-2.0% of Si; 
 0.005-0.3% of Sn; and 
 Al and unavoidable impurities, 
 wherein the aluminum alloy sheet has a microstructure in which:
 compounds each having an equivalent circular diameter in a range of 0.3-20 ∥m, as examined with an SEM having a magnification of 500 times, have an average number density of more than 0 count/mm 2  and 5,000 counts/mm 2  or less; and 
 
 among the compounds examined with the SEM, compounds comprising Sn in an amount of 0.5 mass % or more as identified with an X-ray spectrometer have an average proportion in number of 0% or more and less than 50%. 
 
     
     
         2 . The aluminum alloy sheet for forming according to  claim 1 , further comprising at least one selected from the group consisting of
 more than 0% and 1.0% or less of Mn,   more than 0% and 1.0% or less of Cu,   more than 0% and 1.0% or less of Fe,   more than 0% and 0.3% or less of Cr,   more than 0% and 0.3% or less of Zr,   more than 0% and 0.3% or less of V,   more than 0% and 0.05% or less of Ti,   more than 0% and 1.0% or less of Zn, and   more than 0% and 0.2% or less of Ag, in terms of mass %.