A comparative study of the microstructure and corrosion resistance of Fe-based/B4C composite coatings with Ni-added or Cu-added by vacuum cladding

•Composite coating prepared by vacuum cladding shows metallurgical bonding with steel.•Ni and Cu increase the hardenability of coating matrix and form martensite.•The size of hard phase in Cu-added coating is finer than that in Ni-added coating.•The addition of Ni or Cu significantly improve the corrosion resistance of coating.