Microstructure and wear properties of Fe-based hardfacing coating reinforced by TiC particles

In the present study, Fe-based hardfacing coating reinforced by TiC particles was obtained by manual shielded metal arc welding (SMAW) in which H08A bare electrode was coated with fluxes, to which different measures of ferrotitanium, rutile, graphite, calcium carbonate and calcium fluoride had been added. The microstructure and wear properties of the hardfacing coating were studied by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), an X-ray diffractometer (XRD) and a wear test. The results indicate that TiC particles are produced by direct metallurgical reaction between ferrotitanium and graphite during welding. TiC particles are uniformly dispersed in the matrix of lath martensite and retained austenite with particle sizes in the range 3-5 μm. Fe-based hardfacing coating reinforced by TiC particles is found to possess better wear resistance and lower coefficient of friction than that of AISI 1045 steel substrate.