عنوان مقاله [English]
نویسنده [English]چکیده [English]
In this paper effect of heat input on the microstructure and wear resistance of cobalt base super alloy (stellite 4) cladded on precipitation hardened martensitic stainless steel 15-5PH were investigated. For this purpose, stellite 4 filler metal was clad on 15-5PH steel by gas tungsten arc welding process (GTAW). The different input heats were controlled as function of welding current, welding voltage and speed of cladding. The microstructure, hardness and wear resistance of clads were investigated by optical microscopy, scanning electron microscopy, Vickers micro-hardness and pin-on-disc wear tests. The results showed that the microstructure of the clad layer consists of dendritic Co-rich solid solution and lamellar eutectic carbides in inter-dendritic spaces. Decreasing the heat input creates a finer dendritic structure and finer eutectic carbides distribution. In addition decreasing the heat input reduces the dilution of iron in the clad layer. Therefore the hardness and wear resistance of clad increase by decreasing of heat input.