Ni–Cr–B–Si–C coatings were deposited by laser cladding and effects of additional iron (Fe) as a result of
dilution from the steel substrate were investigated. It was found that for Fe contents of up to around
25 wt%, chromium borides with higher Fe fractions could form but further increase of the Fe content to
over 40 wt% entirely suppressed the precipitation of primary Cr borides. Similarly, the Ni–Si–B eutectics
were diminished as dilution increased. By reducing the amount of chromium borides and Ni–Si–B
eutectics, excessive iron contents degraded the hardness of Ni–Cr–B–Si–C coatings from 800 to 500 HV.
These findings can be used to explain the role of dilution in evolution of microstructure and properties
of Ni–Cr–B–Si–C coatings and to tune the processing parameters to obtain the desirable deposits.