Wear and Corrosion Resistance of FeCoNiCrNbx High‐Entropy Alloy Coatings Prepared by Laser Cladding

304 stainless steel is extensively applied in diverse fields, yet exhibits inadequate wear and corrosion resistance under service conditions.Compared with conventional single FCC‐phase high‐entropy alloy coatings, eutectic high‐entropy alloy (EHEA) coatings exhibit superior synergy of strength and toughness, corrosion and wear resistance. Herein, FeCoNiCrNbx coatings (where x = 1.0 and 2.0) were produced on 304 stainless steel by means of laser cladding (LC) to clarify Nb content effects on coating microstructure, wear/corrosion performance, and reveal phase evolution and corrosion mechanisms. The addition of Nb forms a FCC + Laves dual‐phase structure, which improves the hardness, wear resistance, and acid corrosion resistance of the coating. The x = 2.0 coating formed a FCC + Laves dual‐phase structure, showing minimal microcracks, maximum microhardness, and the lowest wear rate and volume. In dilute 0.1 M H 2 SO 4 , 304 substrate shows lower corrosion current ( i corr = 1.295 μA/cm 2 ) without phase‐interface microgalvanic effects. By contrast, the x = 1.0 coating obtains superior corrosion resistance in aggressive 0.5 M H 2 SO 4 , with corrosion‐current density of 7.921 μA/cm 2 versus 56.481 μA/cm 2 for substrate. Its polarization resistance is 5.4 times higher, alongside positive corrosion potential, low passive current density and elevated Fe ox /Fe hy ratio. This work confirms the great engineering application potential of FeCoNiCrNbx coatings for wear and corrosion resistance.