Comparing the performance of HIPed and Cast Stellite 6 alloy in liquid–solid slurries

In this paper, results from erosion–corrosion tests performed under liquid–solid erosion conditions in 3.5% NaCl liquid medium are reported. The focus of the paper is to compare the behaviour of Cast and Hot Isostatically Pressed (HIPed) Stellite 6 alloy in terms of their electrochemical corrosion characteristics, their resistance to mechanical degradation and relationship between microstructure and degradation mechanisms. It has been shown that HIPed Stellite 6 possesses better erosion and erosion corrosion resistance than that of Cast Stellite 6 and two stainless steels (UNS S32760 and UNS S31603) under the same solid loading (200 and 500 mg/l), and same temperature (20 and 50 °C). The material removal mechanisms have been identified by using atomic force microscopy (AFM) and shown preferential removal of the Co-rich matrix to be less extensive on the HIPed material.