Method for producing a sheet or strip from an aluminium alloy, and a sheet, strip or shaped part produced thereby

A method for producing a sheet or strip from an aluminum alloy comprising:

• from 2.0 to 5.5 wt % magnesium (Mg),
• from 0.2 to 1.2 wt % manganese (Mn),
• optionally
• up to 4.0 wt % zinc (Zn),
• up to 0.45 wt % silicon (Si),
• up to 0.55 wt % iron (Fe),
• up to 0.35 wt % chromium (Cr),
• up to 0.2 wt % titanium (Ti),
• up to 0.2 wt % silver (Ag),
• up to 0.8 wt % copper (Cu),
• up to 0.8 wt % zirconium (Zr),
• up to 0.3 wt % niobium (Nb),
• up to 0.25 wt % tantalum (Ta),
• up to 0.05 wt % vanadium (V),
• and a remainder comprising aluminum and inevitable production-related impurities, with up to at most 0.05 wt % of each and all together totaling at most 0.15 wt % inevitable production-related impurities, wherein the method comprises the following steps:
• casting a rolling slab;
• optional homogenization of the rolling slab;
• hot rolling the rolling slab into a hot-rolled sheet or strip;
• cold rolling the hot-rolled sheet or strip to a final thickness, optionally with an intermediate annealing of the sheet or strip, wherein the sheet or strip that has been cold-rolled to the final thickness has at least one intermetallic phase with first particles having an average particle size of 5 μm to 10 μm;
• and
• heat treatment of the sheet or strip that has been cold-rolled to the final thickness, including recrystallization annealing with subsequent accelerated cooling and optionally a stabilization of the sheet or strip that has undergone accelerated cooling, wherein the heat-treated sheet or strip has an average crystal grain size D of ≤60 μm and the average crystal grain size D in mm and a number A of first particles per mm2 in the aluminum alloy satisfy the condition:
• D
• *
• A
• >
• 1.8
• .