Abstract
In the current study, Mo-Fe-C hardfacing alloys were fabricated by a gas tungsten arc welding (GTAW) process on DIN St52 steel substrates. The primary fillers were designed so that after welding, three microstructures of hypoeutectic, eutectic, and hypereutectic were obtained. The microstructures of the specimens were studied by optical microscopy with selective etchant, Groesbeck's reagent, and scanning electron microscopy (SEM). The phase and chemical composition of microstructures are investigated by X-ray diffraction (XRD) and energy-dispersive spectroscopy, respectively. The results showed the existence of two kinds of carbides, Mo2C and (Mo,Fe)6C, in the specimens. The tribological behavior of the samples was investigated under two different normal forces by pin-on-disk tests. Two wear mechanisms, sliding and adhesive wear and brittle fracture, were distinguished by SEM analysis of the worn surfaces. The findings showed that by increasing the amount of carbides from a hypoeutectic structure to hypereutectic, the abrasive behavior of specimens would improve.