Microstructure and mechanical properties investigation of stellite 6 and Stellite 6/TiC coating on ASTM A105 steel produced by TIG welding process

Abstract

In this study, Stellite 6/TiC particle composite with 10, 20, 30 and 40% wt TiC were coated on carbon steel substrate using the tungsten inert gas (TIG) process. Microstructure, phase evolution, microhardness and wear resistance of clad layers were studied using different examinations. According to the results, the microstructure of Stellite 6/TiC cladding consists of eutectic structure, Co solid solutions matrix and primary TiC particles. The X-ray diffraction (XRD) analysis revealed the presence of two allotropic structure of cobalt (Co-FCC and Co-HCP), some intermetallic of Co and Ti and some types of carbides in the coating; those are reason of the strong interfacial bonding which increase wear resistance of the coating. Compared with carbon steel substrate, the Stellite 6 and Stellite 6/TiC particle composite cladding enhanced the hardness and wear resistance by 2–3.5 times and 2–12 times, respectively. With more TiC content, more improvement in the hardness and wear resistance was obtained.