The effect of rare earth on microstructure and wear resistance of plasma electrolytic carburizing layer on 17-4PH stainless steel

A novel plasma electrolytic carburizing (PEC) technology was developed by virtue of rare earth (RE). High quality of microstructure and excellent performance of the PEC layer with RE addition were obtained. For 17-4PH stainless steel after PEC treated with 1-12 g/L CeCl3 & sdot;7H2O addition, not only decrease the surface roughness of the carburized layer and increase the density of the carburized layer, but also efficiently increase the thickness of dense layer from 19 mu m for PEC sample to 37 mu m for PEC+RE sample. More importantly, the performances of the RE carburized layer were dramatically promoted. After PEC treatment with RE addition, the hardnesses of the stainless steel can be increased from 350 H3/0.025 to 573 H3/0.025, the friction coefficient of stainless steel can be decreased from 0.81 to 0.48, especially, the wear rate of stainless steel can be decreased more than 10 times than that of untreated one. The present research provides a wonderful insight into PEC treatment of steel with high efficiency and excellent performance.