Effect of Components Geometry on the Conventional and Active Screen Plasma Nitriding Behavior of AISI H13

In this research, the effects of plasma nitriding parameters including frequency and duty cycle were investigated on samples with different grooves in the two method conventional plasma nitrided (CPN) and active screen plasma nitrided (ASPN). The samples with thicknesses of the grooves of 2, 4, 6, 8 and 10 mm were nitrided under the atmosphere content of 75%H2-25%N2, The temperature of 500, the duty cycles of 40%, 60%, 80%, and the frequencies of 8, 10 kHz for 5 hours. Then the properties of the nitrided samples were investigated by SEM, XRD, Micro Hardness, and Roughness measurements. The results of the experiments indicated that with increasing frequency, the duty cycle, and the thickness of the grooves, the roughness of the surfaces increased in both methods. Hallow cathode effect occurred at the sample with 2 mm width groove, in the CPN method, leading to the overheating of the sample. The surface morphology of the CPN treated samples consists of cauliflower shape surface nitrides while the surface of the ASPN samples are covered by the hexagonal particles with uniform distribution. Also, it was found that, the compound layer of the treated samples in two method nitriding consisted of ´γ: Fe4N and ε: Fe2-3N phases.