| 摘要 |
PROBLEM TO BE SOLVED: To provide a 6000 series aluminum alloy for forming having excellent paint bake hardenability, and to provide a production method therefor having excellent productivity.SOLUTION: In the 6000 series aluminum alloy containing, by mass, 0.2 to 1.0% Mg and 0.5 to 1.5% Si, the density of β'' phase deposits observed after the application of heat treatment to a product at 180°C for 9 hr is 3,000 to 7,000 pieces/μm, and proof stress after the restoration of solute atom clusters present in the product is 90 to 140 MPa. In the production method therefor, a prescribed aluminum sheet is subjected to solution quenching treatment so as to be held at 480 to 580°C for ≤5 min and thereafter to be cooled at a cooling rate of ≥5°C/s, and is next subjected to high temperature previous aging treatment in the temperature range of 150 to 250°C for 30 s to 10 min. Further, by performing a low temperature previous aging treatment in warm water of pH 4 to 7, excellent adhesive properties can further be imparted thereto. |
