Microstructure and Corrosion Resistance of Ni‐Cr‐Mo‐Si/Cr₃C₂ Coatings Prepared by Laser Cladding

ABSTRACT This paper enhances the corrosion resistance of Q235A steel in a seawater environment by employing laser cladding technology to prepare Ni‐Cr‐Mo‐Si/ x Cr 3 C 2 ( x = 0, 5, 15 wt%) hydrophobic coatings on its surface. The results indicate that the introduction of Cr 3 C 2 substantially refines the microstructure of the coating and forms additional reinforcing phases, primarily including Cr 23 C 6 , Ni 3 C, and Cr 1.12 Ni 2.88 . The addition of an appropriate amount of Cr 3 C 2 significantly contributed to the enhanced formation of hard phases. Specifically, when the Cr 3 C 2 content is 15%, the average hardness reached a maximum of 395.2 HV 0.5 . Combining wettability tests with electrochemical results, the Ni‐Cr‐Mo‐Si/Cr 3 C 2 coatings show lower surface energy, improved hydrophobicity, and reduced corrosion rates. When the Cr 3 C 2 content reaches 15%, the synergistic effect of hydrophobicity and carbides optimized the corrosion resistance of the coating. Therefore, this paper reveals the multifaceted roles of Cr 3 C 2 in refining the microstructure and improving corrosion resistance.