Thermal stability and phase decomposition of nitrided layers on 316L and 310 austenitic stainless steels

Results showed that the metastable solid solution, supersaturated and disordered in nitrogen, obtained after nitriding under cold plasma of austenitic stainless steels, is decomposed for relatively short times and at temperature ranging from 723 K to 823 K, in different ways, depending on chromium content in steel. On the other hand, if the annealing is made at low temperature and for fairly long time, the γN phase returns to equilibrium and gives a stable phase, the M4N nitride in this case (were M is compound of iron, chromium and nickel considered steel).