Comparative study on plasma Nitriding in Cathodic cage with conventional Nitriding of the austenitic stainless steel 316

The present work is based on a comparison between nitriding plasma technique described as CCPN (Cathodic Cage Plasma Nitriding) and the conventional DCPN (DirectCurrent Plasma Nitriding). Here the nitriding process applied on the AISI 316 stainless steel was investigated under the following conditions:constant pressure of 5mbar at temperatures of 400, 450 and 500°C. The cathodic cage used allowed the deposition and thermal treatment in three-dimensional way on samples and guaranteed excellent deposition rate and the growth of the layersonactivated thermal surfaces. The nitriding process appliedwith the cathodic cage produced the same properties related to the conventional one (DCPN) by eliminating common problems associates with this procedure, especially, the edge effects. The thickness of the nitrided layer obtained by the usage of the cathodic cage was closer to the one obtained by DCPN process, however with lower adhesive wear when is compared with ionic nitriding. The ideal temperature in nit riding mixture of 80% N2 - 20% H2 for the procedure with the cathodic cage was 450°C. These also contributed to thickening the layers and improve themicro hardness as well as the wear resistance of the material.