Effect of Al ₂ O ₃ Content on the Microstructure and Performance of Fe–Cr–Ni‐Based Coatings Fabricated Underwater

Fe–Cr–Ni‐based coatings with different Al 2 O 3 contents (0, 5, and 10 wt%) are successfully prepared by the underwater local dry laser cladding. The microstructure, corrosion resistance, and wear resistance of the coatings are investigated. The results indicate that all coatings contain ferrite (δ) and austenite (γ). As the Al 2 O 3 content increases from 0 to 10 wt%, the δ phase fraction increases, and the hardness of the cladding layer shows an upward trend, reaching the highest value at 10 wt% Al 2 O 3 content. Similarly, both wear resistance and corrosion resistance are also improved. The increase in Al 2 O 3 content promotes solid‐solution strengthening and fine‐grain strengthening of the Fe–Cr–Ni‐base coating.