<p>This study investigates the application of laser cladding to repair and enhance ultra-supercritical heat-resistant steels using Fe-Cr-Ni-based alloy powder on a 9Cr steel substrate. The microstructure and properties of the cladding layer were characterized by OM, SEM, EDS, XRD, and Vickers hardness testing. Results show the cladding layer, approximately 1.2&#xa0;mm thick, forms a sound metallurgical bond with the substrate. Its microstructure consists primarily of lath martensite, with a minor amount of ferrite near the interface. A planar crystallization zone at the bond interface confirms good metallurgical compatibility. The microhardness of the cladding layer is significantly higher than that of the substrate and heat-affected zone. This enhancement is attributed to solid-solution strengthening, dislocation strengthening, and precipitation strengthening from Cr₇C₃ and Cr₃C₂ carbides. Electrochemical corrosion tests in 3.5&#xa0;wt.% NaCl solution demonstrated that the cladding layer exhibits superior corrosion resistance, as evidenced by a higher corrosion potential and greater polarization resistance than the substrate. The findings confirm laser cladding with Fe-Cr-Ni alloy is a cost-effective and efficient method for repairing and enhancing critical power plant components, improving their performance and service life in demanding environments.</p>