Effect of plasma nitriding on wear and pitting corrosion resistance of X2 CrNiMoN 22 5 3 duplex stainless steel

Plasma nitriding of an X2 CrNiMoN 22 5 3 duplex stainless steel was performed in a high-frequency pulsed plasma installation at 400 degrees C and 350 degrees C. The influence of the temperature is discussed in terms of the nitrogen distribution between the nitride layer and the bulk material. An improvement in microhardness, module of elasticity, wear resistance and friction coefficient was achieved after plasma nitriding. Corrosion resistance was influenced in different ways by the two temperatures of nitriding. A temperature of 350 degrees C did not affect the corrosion resistance remarkably, whereas treatment at 400 degrees C resulted in a significant decrease in the pitting corrosion resistance. (C) 1998 Elsevier Science S.A.