Effect of CeO₂ on the Microstructure and Properties of In Situ Nano-VC Reinforced Sub-micron Fe-Based Laser Cladding Layers

The preferential corrosion susceptibility along grain boundaries significantly increased as the grain size of the Fe-based matrix in the cladding layers reached the submicron scale. The addition of an appropriate amount of CeO₂ was introduced to investigate its effect on the microstructure and properties of in situ nano vanadium carbides reinforced submicron Fe-based laser-cladded layers. The results indicated that a moderate amount of CeO₂ promoted the refinement of the matrix and in situ carbides and contributed to the uniform distribution of microstructures, but an excessive amount of CeO₂ led to carbide accumulation. With increasing addition of CeO₂, the hardness and corrosion resistance of the cladding layers showed an overall trend of increasing and then decreasing. The optimal overall performance of the cladding layer was attained with an addition of 1.5 wt.%. Compared with the layer without CeO₂, the corrosion resistance was improved by approximately 4.9-fold and the hardness by 114 HV_0.2.