Microstructure, Tribological Performance, and Wear Mechanism of Cr- and Mo-Reinforced FeSiB Coatings by Laser Cladding

FeSiB coatings with the additions of Cr and Mo were fabricated on S355 steel using a laser cladding. The surface and cross section morphologies, chemical elementals, phases and valences of obtained coatings were analyzed using a scanning electron microscope, energy-dispersive spectroscope, x-ray diffraction, and x-ray photoelectron spectroscopy, respectively. The corrosive-wear properties of Cr- and Mo-reinforced FeSiB coatings in 3.5% NaCl solution were analyzed using a ball-on-disk wear tester. The results show that the grain shapes of FeSiB, FeSiBCr and FeSiBCrMo coatings are sequentially transformed from the rod-shaped and dendritic grains to the equiaxed grains, the additions of Cr and Mo play the roles of refinement and dispersion strengthening. The average coefficients of friction of FeSiB, FeSiBCr and FeSiBCrMo coatings are 0.68, 0.47, and 0.65, respectively, and the corresponding wear rates are 82.8 × 10⁻⁶, 57.5 × 10⁻⁶, and 79.9 × 10⁻⁶ μm³·N⁻¹·m⁻¹, respectively, showing that the corrosive-wear resistance of FeSiBCr coating is the best among the three kinds of coatings, the phase distribution is the main factor of affecting the wear resistance.