Effect of Laser Power on the Organization and Properties of NiCrFeCu-45%WC Composite Cladding Layer

In order to improve the wear resistance of 42CrMo steel for rock drill bits, NiCrFeCu-45%WC composite cladding layer was prepared by laser cladding technology, and the influence of laser power at 1500W-1800W on the organization evolution and mechanical properties of the cladding layer was systematically investigated. The XRD, SEM/EDS and friction wear tests show that the physical phase of the cladding layer is dominated by γ-(Ni,Fe) solid solution, accompanied by the formation of WC, W2C and Cr23C6/M7C3 carbides. When the power was increased to 1600 W, the trace WC decomposed into W2C particles, and the grains remained small in size due to heterogeneous nucleation and Zener pinning effect, and the microhardness of the cladding layer reached a peak (average 747.6 HV1.0), which was 1.4 times higher than that of the substrate, and at this time, the wear rate was at a minimum of 1.6×10-2 mm3/Nm. The study showed that the The optimal wear resistance of the cladding layer at 1600 W is achieved through fine grain strengthening, hard phase dispersion and carbide synergism.