Effect of TiC particles on the microstructure, hardness and wear resistance of Stellite 6 clad layer fabricated on stainless steel 316 by TIG process

Stellite 6 clad layer containing different contents of TiC particles (0, 10, 20 and 30) was cladded on stainless steel 316 by Gas-Tungsten arc welding (TIG) with DCEN current. Microstructure of clad layers was studied using optical microscopy and scanning electron microscopy (SEM). X-ray diffractometery (XRD) was applied to study the phase evolution and structure of clad layers. Hardness profiles were obtained by microhardness testing. Wear testing was performed by pin on disk method to evaluate the wear resistance of cladded samples, and wear mechanism was investigated by scanning electron microscopy (SEM). According to the results microstructure of clad layers included dendritic cobalt solid solution together with a layer structure containing cobalt solid solution, TiC and small quantities of Co3Ti, CrFe7C0.45, CoCx. Stellite- 20wt.% TiC clad layer showed the maximum wear resistance and hardness among different compositions. Higher and lower amounts of reinforcing particles resulted in the coarsening of cobalt solid solution dendrites and lower hardness values. The dominant wear mechanisms on the surface of clad layers were determined to be abrasive and adhesive mechanisms.