The duplex treatment consisted of a plasma nitriding at 470oC for 4 h and subsequent coating with TiN layer was applied on AISI 304L stainless steel. The article is focused on a study of the chemical composition and mechanical properties of duplex system. GDOES method, laser confocal microscopy, nano-hardness and indentation test were employed to characterize the chemical composition, depth profiles, surface morphology, hardness, adhesion.