Abstract In this work, the corrosion-wear synergistic effect for nanocrystalline Fe(Al), 20 wt.% Al2O3/Fe(Al) composites with and without 4 wt.% Cr in artificial seawater (3.5% NaCl aqueous solution with 60 kg/m3 quartz sand) was investigated. The results showed that the main damage behavior of Al2O3/Fe(Al) composites was a corrosive effect because of its poor corrosion resistance and high hardness, whereas for Fe(Al) material, the main damage mode was a chiseling action by solid particles, due to its relatively low hardness. With 4 wt.% Cr addition, the erosion weight loss at different erosion rates decreased by more than 30%. The Al2O3/Fe(Al) composites had good pure wear resistance, while poor corrosion resistance resulted in an increase in the interaction of corrosion and wear (about 70% of the total damage amount).