effect of grain size on diffusion of nitrogen in heat treated ck45 plain carbon steel

in this study, the effect of grain size on nitrogen diffusion into ck45 has been investigated. in order to obtain different grain sizes, samples were annealed and normalized at various temperatures and durations.the grain size was determined with clemex vision software. then, the specimens were exposed to dc plasma nitriding treatment and again analyzed by optical microscope ,scanning electron microscope and x-ray diffraction analysis. results propose power equation for variations of diffusion depth versus grain boundary density (gbd).