Abstract
Modelling of plasma reactors for steel surface nitriding has been achieved in discharge and post-discharge conditions of N2 flowing gas. Diagnostics and calculations have been focused on the N2(X, V) vibrational molecules and N atoms which are the most populated long living species. It has been demonstrated that these neutral active species produce steel surface nitriding with the same characteristics than classical ion processes : composition and depth of γ'Fe4N and N diffusion coating following the Fe-N diffusion laws