Study of plasma nitriding and nitrocarburizing for higher corrosion resistance and hardness of 2205 duplex stainless steel

2205 duplex stainless steel despite possessing good corrosion resistance suffers from low hardness. With a view to improve hardness and corrosion resistance, plasma nitriding and nitrocarburizing processes were performed at 350, 400, 450 and 500 °C for 4 h. Specimens treated at 400 °C by plasma nitrocarburizing exhibits the highest corrosion resistant with a significant raise in surface hardness. At higher temperatures, specimens treated by these processes show poor corrosion resistance. This study highlights the difference in plasma nitriding behavior of the ferrite and austenite phases and not so different behavior of these phases when subjected to plasma nitrocarburizing.