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Fe-based composite coating prepared onto the component of guide wheel using ultrasonic frequency inductive cladding (UFIC) technique has been investigated in terms of microstructure, phase constitutions, microhardness and elevated temperature wear behavior by scanning electron microscopy (SEM), energy-dispersive spectrometer (EDS), X-ray diffraction (XRD), Vickers microhardness tester and ball-on-disc wear tester. The results indicated that the primary phase in the coating contained austenite γ-Fe, eutectic γ-Fe/(Cr,Fe)2B, boride (Cr,Fe)2B and precipitation enriched in Mo. The average microhardness of the coating was 760 ± 10 HV0.2, which was three times higher than that of the substrate. With increasing temperature, the friction coefficients of the coating and high-chromium cast iron decreased gradually while the wear rates increased during dry sliding wear condition. The relative wear resistance of the coating was 1.63 times higher than that of the high-chromium cast iron at 500 °C, which was ascribed to the hard borides with high thermal stability uniformly embedded in the coating and the formation of dense transfer layer formed onto the worn surface. The high temperature wear mechanism of the coating was dominated by mild abrasive wear. The study revealed that Fe-based composite coating had excellent high temperature wear resistance under dry sliding wear condition.

Induction melted FeCrB metamorphic coatings deposited onto Q235 steel were produced using ultrasonic frequency inductive cladding (UFIC) technique. The measurements of X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectrometer (EDS), transmission electron microscopy (TEM), microhardness tester and ball-on-disc wear tester were used to determine the microstructure, microhardness and dry-sliding wear resistance coupled with wear mechanism of clad coatings. The experimental results show that C+ clad coating consists of austenite γ-Fe, interdentritic lamellar eutectics γ-Fe/(Cr,Fe)2B and borides (Cr,Fe)2B as the reinforcing phase whilst the phases of ferrite α-Fe, borides Cr1.65Fe0.35B0.96 and eutectics α-Fe/Cr1.65Fe0.35B0.96 are identified in M clad coating. The average microhardness of the C+ and M clad coating is more than 3-times than that of the substrate. The wear resistance of the C+ and M clad coating improves 5.18, 6.08 times compared with that of the substrate at applied load of 20 N, respectively, which contributes to the occurrence of the crystalline–amorphous phase transition by friction treatment and uniformly distributed borides embedded in the ductile solid solution matrix.

Iron nitride (FexN) is obtained by the mixing technology with laser and plasma beams coaxially on the surface of pure iron in atmosphere. In this technology, laser and plasma provide heat source and nitrogen ion source, respectively, easily to nitriding the sample. The feasibility of the method is analyzed in theory. Small-angle X-ray diffraction measurements reveal formation of iron nitride in the as-treated sample, and scanning tunneling microscope measurements describe the surface profiles of the irradiated area, at different laser energy densities or different scanning velocities.