Tailoring corrosion resistance of laser-cladded Ni/WC surface by adding rare earth elements

The corrosion is a major limiting factor for steel in the harsh environments and can be controlled by depositing protective passive coatings. Nickel-based alloy cladding of steel offers a solution by enabling better wear and corrosion resistance, and high bonding strength. The laser surface cladding of steel was conducted using a high-power direct diode laser. Layers of tungsten carbide in Ni (40% Ni-60% WC) combined with 1 and 2% lanthanum oxide (La2O3) and cerium oxide (CeO2) were deposited on ASTM A36 steel substrate. The X-ray diffraction and scanning electron microscopy were employed to study the morphology, microstructure, and phase evaluation of the cladded layer. Further, anodic polarization on the laser-cladded coupons in 3.5 wt% NaCl shows significant enhancement of the corrosion resistance. The addition of La2O3 and CeO2 improves the corrosion resistance and the hardness of the clad.