Ni60CuMoW alloy power was clad on 45 steel surfaces using a synchronization powder feeding method by 6kW
transverse-flow CO2 laser apparatus. The effect of laser power and heat treatment process on corrosion resistance of the
cladding layer was investigated. The microstructure and mechanical property were analyzed by X-ray diffractometer
(XRD), scanning electron microscope (SEM), energy depressive X-ray spectroscopy (EDX), microhardness meter
and PS-268A electrochemical test equipment. The results show that the cladding layer is mainly composed of γ (Ni, Fe),
solid solution (Ni, Cu), compounds Ni31Si12, Cr5B3, CrB, Ni3B, FeNi3, M23C6 (Cr23C6 or (Fe,Ni) 23C6) phase and a small
amount of WC or W2C. With the increase of laser power, corrosion resistance and microhardness has been greatly
improved. Compared with the untreated substrate, the maximum self-corrosion potential of single-pass layer at laser
power 3.2 kW in 3.5% NaCl saturated solution increases by 136.2mV, and the lowest corrosion current density decreases
by 2 orders of magnitude. The mean microhardness of treated samples raises by 5.17, 4.90 and 4.89 times, respectively.
The corrosion potential of multi-pass layer increases by 437.6mV and corrosion current density decreases by one order of
magnitude than that of single-pass layer sample. After temper 600°C heat treatment, the primary dendrite and block (or
needle) eutectic in cladding coatings become more uniform, the maximum self-corrosion potential increases by 45.5mV
and corrosion current density also decreases obviously.