The effects of plasma nitriding process parameters on the wear characteristics of AISI M2 tool steel

The main aim of this work is to evaluate the effects of the plasma nitridin g process on AISI M2 tool steel. In previous work, treatment time and tempe rature were varied to identify the treatment conditions for good wear behav iour. In the present work, the treatment time was fixed while temperature a nd gas pressure were varied. Samples were characterised by glow discharge o ptical spectroscopy, scanning electron microscopy, X-ray diffraction, surfa ce microhardness and wear test. The specimens nitrided at 400 and 900 Pa sh owed the best wear performance, which is possibly due to reduction of the f riction coefficient and the low adhesive wear observed. Samples processed a t 200 Pa showed spalling during the wear test, indicating a brittle surface .