The toughness of in-situ synthesized VC/Fe composites with a lot of uniformly distributed fine disperoids can be deteriorated due to the existence of some net-like Fe3C particle at grain boundary.The effects of heat treatment on microstructure and properties of in-situ synthesized VC/Fe composites have been approached.The results show that heat treatment can change the morphology and amounts of Fe3C phase at grain boundary

however

it dose not affect the size and distribution of VC particle.With increasing the austenizing time

the amounts of Fe3C phase can be decreased with the morphology trending towards discontinuous net-like structure.The composites is mainly composed of dispersively distributed VC particles and martensite with austenizing for 3 hours at 960 ℃ and quenching

where the hardness of the composites is 62 and impact toughness is 7.9 J/cm2.