Austenitic stainless steel (AISI 316L) is nitrided by inductively coupled plasma using a gas mixture of N(2) and H(2) at temperatures between 530 K and 650 K, and the corrosion resistance as well as the interfacial contact resistance (ICR) are measured in a simulated proton exchange membrane fuel cell (PEMFC) environment. After plasma nitriding, a nitrogen-expanded austenite layer, the so-called S-phase is formed in all nitrided samples. The ICR value of the nitrided samples decreases to approximately 10 m Omega cm(2) after plasma nitriding. The sample nitrided at 590 K shows the best corrosion property, while the corrosion resistance of the sample nitrided at higher temperatures decreases because of the formation of Cr-depleted regions in the nitrided sample. By using high-density plasma, the process temperature can be reduced to such a low temperature that Cr depletion is not significant, but a dense S-phase is formed. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.