To provide an Al alloy sheet for molding which has satisfactory hem bendability and high baking hardenability.
The Al alloy sheet comprises 0.4-0.7% Mg and 0.8-1.2% Si, one or more of metals selected from 0.03-0.4% Mn, 0.01-0.4% Cr, 0.01-0.4% Zr, 0.01-0.4% V, 0.03-0.5% Fe, 0.005-0.2% Ti and 0.03-2.5% Zn, in which the content of Cu is controlled to ≤0.1%, and the balance substantially Al. In a region of 1/4 of the sheet thickness from the surface, cube orientation density is more than two fold of gross orientation density, and is four fold of that of a random sample. The Al alloy sheet has an electric conductivity of ≤54%IACS, and a mean crystal grain size of ≥4.5 in an ASTM number. Hot rolling is started at ≥370°C so as to obtain a sheet thickness of 1.0-8.0 mm and a finishing temperature of 180-350°C. Further, cooling is performed from the temperature range in the finishing of the hot rolling to ≤100°C at ≤100°C/min. Also, after cold rolling at a rolling ratio of ≥30%, solution treatment is performed under holding at ≥480°C for ≤5 min or without the holding, and cooling is performed to 50 to <150°C at ≥100°C/min. Then, stabilization treatment is performed within the above temperature range for ≥2 hr.
HIBINO AKIRA
MURAMATSU TOSHIKI
SAGA MAKOTO
TAKADA TAKESHI
SATO YUICHI
TOYOTA MOTOR CORP
NIPPON STEEL CORP