Characteristics of Fe-based alloy coating produced by plasma cladding process

The clad coating of Fe-based alloy is produced on the low carbon steel plate by plasma cladding process. The phases and structures of the clad coating are investigated by scanning electron microscopy (SEM), X-ray diffractometer (XRD) and energy-disper pectrometer (EDS). The microstructures of the clad coating belong to austenite and hypoeutectic structure. The primary phases contain dendritic austenite γ-FeNi and interdendritic (Fe,Cr)7(C,B)3 and (Fe,Cr)3C2. γ-FeNi is a non-equilibrium phase with an extended solid solution of alloying elements. The properties, particularly the wear resistance, are analyzed in detail. Results of abrasive test show that the wear resistance of Fe-based clad coating improves greatly compared to the quenched mild steel, which contributes to the good microstructures that the hard-phase carbide and boride are uniformly distributed in the dendritic austenite. Microstructures of the coating have important effects on abrasive mechanism and the main mechanism is micro-cutting. The maximum microhardness value of clad coating is about 780 HV. The study reveals that the plasma cladding process has a higher efficiency and better cladding quality and the plasma clad coating has high wear resistance and hardness.