In order to obtain iron-based surfacing alloy with high hardness,various Fe-Cr-Ti-C alloy powders with different Cr content were designed and developed,and the corresponding surfacing layers were prepared on carbon steel substrate by plasma surfacing technology.The microstructure,phase composition and microhardness of Fe-Cr-Ti-C alloy with different Cr mass fraction were analyzed by X-ray diffraction,scanning electron microscope and microhardness tester.The results show that the surfacing layer of Fe-Cr-Ti-C alloy consists of austenite(γ),martensite(M),M₇C₃ and TiC.With the increase of Cr content,the number of martensite matrix structures in the surfacing layer first increases and then decreases,and the number of M₇C₃ gradually increases.The morphology changes from intermittent network to primary hexagon,and TiC is flowered or blocky.The microhardness on the side of the surfacing layer presents a gradient distribution.With the increase of Cr mass fraction,the hardness of the surfacing layer increases continuously.When the Cr mass fraction is 15.0%,it is the best value,and the average microhardness on the top of the alloy surfacing layer is the highest,reaching HV_0.21 186.