Effect of TiN on microstructure and wear resistance of Fe-Cr-C hardfacing alloy

Fe-Cr-C-Ti-N and Fe-Cr-C Surfacing layers were prepared by flux cored wires. The effect of TiN on the wear resistance and microstructure of the surfacing layer was discussed. The rockwell hardness tester was used to test the macrohardness of the surfacing layer. The abrasive wear test of the surfacing layer is carried out by the wet grinding wheel wear tester. Using X ray diffractometer (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), transmission electron microscopy (TEM) and other equipment for testing and analysis. The results showed that the primary M₇C₃ in the surfacing layer containing TiN was significantly smaller than that without TiN and the hardness and wear resistance of the surfacing layer were also improved. Through thermodynamic calculation, TiN is prior to precipitation of M₇C₃ in molten pool cooling process. According to the dynamics calculations, the two-dimensional misfit of TiN/M₇C₃ is 8.43%. TiN can be used as a heterogeneous nucleation site for primary M₇C₃, which refines the M₇C₃ grains.