Cathodic Cage Nitriding of AISI 409 Ferritic Stainless Steel with the Addition of CH4

AISI 409 ferritic stainless steel samples were nitrided using the cathodic cage plasma nitriding technique (CCPN), with the addition of methane to reduce chromium precipitation, increase hardness and wear resistance and reduce the presence of nitrides when compared to plasma carbonitriding. Microhardness profiles and X-Ray analysis confirm the formation of a very hard layer containing mainly epsilon-Fe3N and expanded ferrite phases.