| Recently, in-situ particles reinforced metal matrix composites have attracted much attention in the academic community and industrial sector . The paper studied VC/Fe composite, prepared in intermediate frequency electromagnetic furnace. Enhencement phases VC of the composite were synthesized by method of reaction cast. Microstructure and properties of the composite were investigated by optical microscope, SEM/EPEM, et al. In order to investigate the figure and distributing of enhencement phases, Fe-V-C system was researched into first of all. The results indicated VC particles showed irregular cube or cosh sharp; In composites contained 1.5%C, VC particles were along austenite crystal boundary, while others of 3%C content were distributed uniformly. SEM/EPEM indicated atomic ratio of C and in V particles was 0.62, and the size of VC particles was 20~100μm. According to the solution thermodynamics model, the forming thermic condition of VC was analysed. It proved that VC particles was formed at about 1250℃,during solidification process. In addition, it demonstrated Ti was benefit to VC gain refining and structure uniformity. It investigated the impact of heat treatment to microstructure and properties of composites. The results showed the appropriate heat treatment made the figure of VC particles nearly round. As a kind of steady phases, VC particles always kept small granularity. Impact toughness of the specimen contained 1.5%C was 6.5～7.5 J/cm2,and hardness was about 55 HRC. The paper discussed VC particles reinforced composites based chromium iron matrix farther, by testing orthogonal optimum design. As a result, the optimized content of as-cast specimen was 2.0%C, 15%Cr, 5%V and appropriate Ti, and after the heat treatment, the content was 2.6%C, 9%Cr, 5%V, with the impact toughness was up to 7.5 J/cm2 and the hardness was above 62 HRC.
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