The Microstructure of Ni-based Surface Infiltrated Layer on Cast Steel Substrate

The Ni-based alloying powder was successfully used as the raw materials for fabricating surface infiltrated layers on cast steel ZG45 substrate through a vacuum infiltration casting technique (VICT). The microstructures of surface Ni-based infiltrated layer, the micro-hardness distribution are investigated. The infiltrated layer includes three areas that are surface part-melting area, melting completely fusion area and diffusion solid solution area. The main composition of surface infiltrated layer was intermetallic compound Cr2B, NiB and solid solution. The main phase of transition layer was solid solution. The micro-hardness of Ni-based infiltrated layer presented gradient change from surface infiltrated layer to substrate. The average micro-hardness was about 550HV.