Electrochemical study of corrosion behavior of wrought stellite alloys in sodium chloride and green death solutions

Corrosion behavior of wrought Stellite 6B and Stellite 6K, which have similar chemical composition but contain different carbon content, in 3.5 wt.% NaCl solution and in Green Death solution is investigated using various electrochemical methods, including potentiodynamic polarization, cyclic polarization, and electrochemical impedance spectroscopy (EIS). The obtained potentiodynamic polarization curves, cyclic polarization curves, and EIS spectra for these alloys are in good agreement, showing that Stellite 6K with higher carbon content is easier corroded due to its larger volume fraction of carbides but the Cr<inf>2</inf>O<inf>3</inf> film formed on this alloy is stronger and more stable than that on Stellite 6B. Further immersion tests on these alloys show that Stellite 6K has less resistance to pitting corrosion.Peer reviewed: YesNRC publication: Ye