Research of Hollow Cathodic Auxiliary Plasma Nitriding of 38CrMoAl Steel

This study has focused on the nitriding of 38CrMoAl steel by hollow cathodic auxiliary plasma nitriding. Nitriding time, temperature and potential of sample were chosen as the influencing factors of orthogonal experimentation. Also, the optimum technological conditions were determined. The testing results showed that the micro hardness of nitriding layer under the best technology of orthogonal experimentation rose noticeably which was 4 to 5 times higher than that of before. Besides, surface roughness of the plasma nitriding sample was as the same as that of before. What is more, there was a 3-μm-thickness white layer in the surface of nitriding sample which comprised ε and γ' phase, and the whole depth of nitriding layer reached 300 μm.