A series of experiments were performed to investigate the one-step laser cladding of Inconel 625 powder, injected off-axially on mild steel substrates. The experiments were carried out using a 6 kW high power diode laser (HPDL) mounted to 6 axis robot system. The rectangular shape of the delivering beam was focused to a spot size of 22 mm x 5 mm on the work piece. The powder feeding head, which consisted of cyclone and flat nozzle, spread the powder stream to a spot size used. The coating samples were produced using different levels of powder feed rate (77 – 113 g/min), constant travelling speed of 400 mm/min and laser power of 6 kW.
The corrosion resistance of the one-step laser-clad coatings were tested in 3.5 wt. % NaCl using electrochemical methods. Laser-clad coating was compared with wrought Inconel 625 alloy, high-velocity oxy-fuel (HVOF) sprayed and plasma transferred arc (PTA) welded coatings. The corrosion resistance of laser-clad coatings was found to be equivalent to corresponding bulk material and superior to sprayed and welded coatings.