Plasma nitriding of austenitic stainless steel samples has been carried out using pulse do glow discharge plasma of NH3 gas at substrate temperature ranging from 350 to 520degreesC. A nitriding time of only 4 h has been found to produce a compact surface nitride layer composed of gamma(N)' phase with a thickness of around 7-12 mum as processing temperature remained between 420 and 450degreesC. The thickness of gamma(N) phase was found to be very thin only about 2 mum after plasma nitriding at temperature below 400degreesC. Microhardness measurements showed significant increase in the hardness from 240 HV (for untreated samples) up to 1700 HV (for nitrided samples at temperature of 460degreesC). For nitriding at higher temperature, i.e. above 460degreesC, the chromium nitrides precipitated in the nitrided layer and caused austenite phase transform into ferrite phase or iron nitrides (gamma' or epsilon). The consequent result of chromium nitride precipitation is the reduction of corrosion resistance of nitrided layer. Compressive residual stresses existed in the nitrided layer due to nitrogen diffusion into austenitic stainless steel. (C) 2003 Elsevier Science B.V. All rights reserved.