Cathodic cage plasma nitriding (CCPN) of austenitic stainless steel (AISI 316): Influence of the different ratios of the (N2/H2) on the nitrided layers properties

In this study, we assess how the ratio (N2/H2) – working atmosphere gas mixture – influences the properties of the layers produced on austenitic stainless steel surface by Cathodic Cage Plasma Nitriding (CCPN). The nitriding atmospheres contained nitrogen and hydrogen in three proportions: 20% N2 + 80% H2, 50% N2 + 50% H2, and 80% N2 + 20% H2 delivered at a flow rate of 20 sccm. The effect of 100% N2 was also examined. The morphology, microstructure and electrochemical properties of the layer produced were studied. The samples characteristics were determined by optical microscopy, x-ray diffraction, microhardness test and electrochemical potential curves.

► A better understanding of the influence of gas mixture has on the layer formed on stainless steel.
► The development of the applications of new technique denominate Cathodic Cage Plasma Nitriding.
► Search for material treated with high resistance to corrosion and low cost.