Effect of treatment time on low temperature plasma nitriding of stainless steel by saddle field neutral fast atom beam source

Recent research carried out in laboratories showed that Saddle field neutral fast atom beam source is a promising method for nitriding of stainless steel. In the present work, the effect of treatment time on the microstructural and mechanical properties of plasma-nitrided stainless steel sample was investigated by this new method. Plasma nitriding was carried out at 420 °C and at a pressure of 0.1 Pa for a time range of 1 to 12 h. SEM–EDX, microhardness tests, optical microscopy and X-ray diffraction (XRD) were used to evaluate the mechanical and structural properties of the nitrided layer. It was found that nitriding time has a pronounced effect on the structural and mechanical properties of low-temperature plasma-nitrided samples and produced a precipitation-free thin hard nitrided layer within a short processing time.