Corrosion Resistance and Wear Properties of an Alloy Coating on 30CrMnSiA Steel for Aircraft Parts Using Laser Cladding
摘要
This study investigated the wear resistance and corrosion behavior of nickel-based (NBLC) and ferrite-based (FBLC) laser-clad coatings deposited on 30CrMnSiA steel for aircraft components. Both cladding samples were studied using x-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), hardness testing, tribological analysis, and electrochemical measurements. The NBLC coating has a cellular-dendritic structure dominated by Fe-Ni, Fe-Ni-Cr, and (FeNi)23C6 phases, with finely dispersive (FeNi)23C6 and Cr5B2 phases embedded in the Ni-based matrix. In contrast, the FBLC coating primarily consists of Fe-Ni-Cr and Fe-Cr solid solutions, resulting in a heterogeneous microstructure with coarse dendritic crystals, cellular crystals, and stripe-shaped ferrite. The homogeneous dispersion of (FeNi)23C6 and Cr5B2 hardening phases endows the NBLC coating with 12% higher average microhardness and 1.5 times greater wear resistance than the FBLC coating. The scanning electrochemical microscopy (SECM) results reveal that the corrosion current of the FBLC coating is twice as high and that the material clearly exhibits local corrosion characteristics. The results of the electrochemical experiments further revealed that the NBLC sample exhibits an evident passivation phenomenon and achieves approximately five orders of magnitude greater corrosion resistance than the FBLC sample does in later stages. These results demonstrate that the wear resistance and anticorrosion performance of the NBLC coating are superior to those of the FBLC coating, making it a suitable protective coating for 30CrMnSiA steel in aircraft parts.