Current study investigates the microstructure and phases of the coating formed by one, two and three consecutive layers of satellite 6 and one layer stellite 6 with 309 austenitic stainless steel and Inconel 617 interlayer on a substrate of precipitation hardening martensitic stainless steel (17-4PH). A conventional pin-on-disc test was used to study the wear resistance. As well, optical microscopy, SEM, EDS and line scan were employed to study the microstructure and wear mechanisms. X-ray diffraction was also used to reveal phases formed in the coating.The results showed that the structure on the surface consisted of carbides in Co-rich solid solution with dendritic structure. There was a gradual increase in the hardness from the substrate towards the clad surface due to the decrease in the size of dendrites and the hardness near the substrate was low because of the dilution of the clad layer with Fe from the substrate. 309 austenitic stainless steel Interlayer results dilution of Fe in coating surface was decreased and hardness was increased. Inconel 617 interlayer cause decrease in hardness. From 1 layer to 3 layer specimen, the wear resistances of the clad layer was increased. 309 austenitic stainless steel Interlayer specimens have the highest wear resistance. Wear rate and weight loss of Inconel 617 interlayer specimens werw the highest. After wear test, hardness and the amount of? (HCP) cobalt phase were increased. Results of the wear studies showed that it was necessary to using of 309 stainless steel as the interlayer.
