Effect of recrystallization and heat treatment on strength and SCC of an Al–Zn–Mg–Cu alloy

•We study effect of recrystallization and aging on strength and SCC of Al alloy.•The strength and SCC resistance decrease with the increase of recrystallization.•Over-aging decreases the influence of recrystallization on SCC susceptibility. The influences of recrystallization and heat treatment on strength, stress corrosion cracking (SCC) of an Al–Zn–Mg–Cu alloy have been investigated by tensile testing, slow strain rate testing combined with scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that with increasing the volume fraction of recrystallization, the strength and SCC-resistance decrease, and the predominated fracture mode transforms from transgranular fracture to intergranular fracture. Over-aging reduces the effect of recrystallization on SCC susceptibility. The differences of strength and SCC resistance are explained on the basis of the role of recrystallization and grain boundary precipitates.