The aim of this present research is to evaluate the tribological behavior of stellite6 coatings on Inconel 617 substrate. Numerous investigations carried out for selecting and improving surface coatings to reduce surface failure of materials in various industries. Superalloys consist of nickel base, iron-nickel base and cobalt base materials used extensively in petroleum, gas and petrochemical industries. Inconel 617 is a nickel base superalloy that has extensive uses because of its high corrosion and oxidation resistance at high temperatures. In this order, cobalt base superalloys such as stellite6 with the chemical composition of Co, 28Cr, 4.5W, 1.1C are good candidates due to their high wear and erosion resistance behavior. In this research stellite6 coating in various passes deposited by use of pulse TIG welding after determining of optimum parameters by use of Taguchi method of experiment design. Microstructural properties were investigated by optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). These results showed that at the surface of coatings, chromium and cobalt rich carbides formed. Line scanning EDS showed that dilution of nickel decreases and microhardness increases by increase of passes. The Pin-on-disc wear tests were used to study the tribological properties of the samples. Results showed that by increasing of passes, the wear resistance increased. The ball-on-disk wear test at high temperature (600 C) were carried out. Scanning electron microscopy, x-ray diffraction and microhardness showed that by oxide adhesion formation on the stellite6 coatings surface, the wear resistance at high temperature compare to inconel 617 substrate increases. Keywords: Superalloy, Stellite6, Wear behavior, Cladding, Inconel 617.
