High-entropy alloys (HEAs) exhibit superior properties for extreme environments, yet the effects of laser scanning speed on the microstructure and performance of laser-clad NiAlNbTiV HEA coatings remain unclear. This study systematically investigates NiAlNbTiV coatings on 316 stainless steel fabricated at scanning speeds of 800–1100 mm/min via laser cladding. Characterizations via XRD, SEM/EDS, microhardness testing, high-temperature wear testing, and electrochemical measurements reveal that increasing scanning speed enhances the cooling rate, promoting γ-(Ni, Fe) solid solution formation, intensifying TiV peaks, and reducing Fe-Nb intermetallics. Higher speeds refine grains and needle-like crystal distributions but introduce point defects and cracks at 1100 mm/min. Microhardness decreases from 606.2 HV (800 mm/min) to 522.4 HV (1100 mm/min). The 800 mm/min coating shows optimal wear resistance (wear volume: 0.0117 mm³) due to dense eutectic hard phases, while higher speeds degrade wear performance via increased defects. Corrosion resistance follows a non-linear trend, with the 900 mm/min coating achieving the lowest corrosion current density (1.656 μA·cm⁻²) due to fine grains and minimal defects. This work provides parametric optimization guidance for laser-clad HEA coatings in extreme-condition engineering applications.

Cr8 steel should be Steel containing ~8 wt.% of chromium is widely used in demanding die applications due to its excellent wear resistance; however, conventional shot peening, while enhancing strength, inevitably increases surface roughness, thereby compromising overall performance. To address this limitation, this study systematically investigates the influence of ultrasonic surface rolling (USR) step size—comparing 0.06 mm and 0.12 mm—on mitigating surface degradation and improving surface integrity. Friction wear and electrochemical corrosion tests demonstrate that USR effectively reduces surface roughness and enhances microhardness. The 0.06 mm step size achieves superior results, yielding the lowest surface roughness (0.8317 μm), highest microhardness (647.47 HV), lowest friction coefficient (0.655), and optimal corrosion resistance (minimum corrosion rate reduction: 3.472 µA·cm⁻², corresponding to an inhibition efficiency of 37.05%). These performance improvements are attributed to the synergistic effects of surface smoothing and work hardening, resulting from more uniform processing achieved under a smaller step size. Consequently, a 0.06 mm step size is determined to be optimal, establishing the integrated shot peening–USR process as a highly effective strategy for enhancing surface properties and extending the service life of critical Cr8 steel components in industrial applications.