WC particle reinforced steel matrix surface composites were successfully prepared by casting-infiltration method

and effects of nickel powder on microstructure and interface of WC/steel matrix surface composites were observed by OM （optical microscope） and SEM （scanning electron microscope） and EDS （energy dispersive spectrometer）. The results reveal that with increasing in nickel powder addition

WC particles in infiltrated layer are increased

which results in the smooth transition between composite layer and the matrix and the improvement of surface quality. In addition

with the increase of Ni powder addition

interface layer exhibits smooth change

and martensite

residual austenite as well as eutectic carbide in the matrix are increased gradually

resulting in the gradient increase of hardness of composite surface layer.