Chemical composition: aluminum Al: balance
Silicon Si: ≤0.25
Copper Cu : ≤ 0.10
Magnesium Mg: 2.2~2.8
Zinc Zn: ≤ 0.10
Manganese Mn: ≤0.10
Chromium Cr: 0.15~0.35
Iron Fe: ≤0.40
Note: Single: ≤ 0.05; Total: ≤ 0.15
Mechanical properties: tensile strength: &;b (MPa) 173 ~ 244
Conditional yield strength: &;0.2 (MPa) ≥ 70
Heat treatment process: 1) Homogenization annealing: heating 440 ° C; holding 12 ~ 14h; air cooling.
2) rapid annealing: heating 350 ~ 410 ° C; holding time 30 ~ 120min; empty or water cooled.
3) High temperature annealing: heating 350 ~ 420 ° C; holding time is 2 ~ 10min or 10 ~ 30min; air cooling.
4) Low temperature annealing: heating 250 ~ 300 ° C or 150 ~ 180 ° C; holding time is 1 ~ 2h, air cooling.
Performance application: manufacturing aircraft fuel tanks, oil pipes, and transportation vehicles, ship sheet metal parts, instruments, street lamp brackets and rivets, hardware products, electrical enclosures, wires used for rivets.