Effect of Cr on corrosion and wear resistances of TiC-VC reinforced ferrite-based laser cladding coatings

The effect of different amounts of Cr in cladding powders on corrosion and wear resistances of cladding layers was investigated by means of X-ray diffractometry (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), potentiodynamic polarization and abrasive wear test. The results showed that phases of cladding layers were α-Fe, TiC, VC and TiVC₂. Retained austenite and Cr₃C₂ would appear with Cr content increasing, and Cr₃C₂ was long strip and distributed alone or together. The corrosion and wear resistances of cladding layers increased firstly and then decreased with the increasing of Cr addition. Moderate amount of Cr could improve hardness and corrosion resistance of cladding layers significantly. The hardness of the cladding layer with 3.0 % Cr reached 1090HV_0.2. The weight loss of cladding layer was only about 1/26 of Q235 steel under the same abrasive wear condition. When the addition of Cr was 9.0%, the cladding layer showed the best corrosion resistance and its corrosion resistance was about 3.26 times than that of the cladding layer without Cr. (authors)