A Comparative Study on Microstructure and Wear Resistance of M2 Alloy Steel Cladding Layers by High-Speed Laser Cladding and Conventional Laser Cladding

Based on the experimental results, this study demonstrates that increasing the laser scanning speed effectively refines the microstructure of the fabricated samples, resulting in finer needle-like martensite and reduced carbide size. Although the average surface hardness decreases due to incomplete austenite-to-martensite transformation at higher speeds, the wear resistance improves significantly. The sample produced with a higher laser scanning speed exhibits the lowest wear volume, which contradicts the conventional hardness-dependent wear behavior. This enhancement is attributed to the refined microstructure, which strengthens resistance to micro-cutting and provides better load support during sliding wear. The findings suggest that microstructural refinement plays a more critical role than hardness in enhancing wear performance under the tested conditions.