Study on microstructure and properties of laser-clad Fe-based (Ti, V)C composite coatings

An in-situ autogenous ceramic phase reinforced laser cladding containing vanadium (V) and titanium (Ti) has been developed for improving the surface properties of rolls in the field of iron and steel metallurgy. In this study, the effect of the V and Ti content on the microstructure, hardness, shear property, and wear behavior in high temperatures of the laser cladding was evaluated. The results showed that with the increase of the V and Ti content, TiC and VC precipitated with a growing volume in the grain and grain boundaries, and their shapes gradually changed from circle to polygon. In addition, the grain size was smaller and smaller while the microhardness was higher and higher. The precipitation of TiC and VC ceramic phase has a bad effect on the shear properties of the cladding layer due to the weak bonding strength between large-size carbide and matrix. The cladding layer with 5 % content of V and Ti showed better wear-resisting properties which are >21 times and twice higher than that without V and Ti at room temperature and 600 °C, respectively. Indicating that the size of the ceramic phase has the most important effect on the wear property because the ceramic particles with larger sizes were easy to dislodge and cause scratches to the specimen.