The invention discloses a novel Al-Mg-Si
alloy material high in strength and resistant to
seawater corrosion and a preparation method thereof. By adoption of the
alloy material, mutual contradiction between the
corrosion resistance and the strength in the ship material designing process is effectively overcome. The
alloy material comprises, by
mass, 1.8-3.6 wt% of Mg, 1.6-3.3 wt% of Si, 0.45-0.65 wt% of Mn, 0.25-0.35 wt% of Cr, 0.15-0.3 wt% of Zr, 0.2-0.3 wt% of Ti, 0.2-0.5 wt% of Ag, no more than 0.03 wt% of each
impurity, no more than 0.1 wt% of all impurities, and the balance Al. According to the novel Al-Mg-Si alloy material high in strength and resistant to
seawater corrosion and the preparation method thereof, the multi-component composite micro-alloyed element design is adopted, and the
smelting and
casting technique, the rolling control method and the solution and aging heat treatment technique are optimized, so that the Al-Mg-Si alloy material which is accurate in component, reasonable in structure regulation and control, and excellent in comprehensive performance is prepared. The tensile strength of the obtained material is not smaller than 375 MPa, the
ductility is not smaller than 12.0%, the intercrystalline corrosion resistance is the first level (according to GB / T 7998-2005), the maximum corrosion depth is 0.03 [mu]m, and the
exfoliation corrosion resistance is the N level (according to GB / T 22639-2008).