Effects of Pretreatment Prior To Electroless Ni-P Plating on Fatigue Behavior of Sae 1045 Steel

Electroless ni-p (en) plating, as an important group of metallic coatings, is employed in a wide range of industrial applications. the current work aims to investigate the effects of pretreatment process before en plating on fatigue behavior of sae 1045 steel. the specimens of rotating bending fatigue test were prepared from the steel in two series. a group of samples was used in as-polished condition as the base metal and the next group of samples was degreased using aston and then naoh 150 gr/lit at the room temperature. subsequently, pickling carried out in an aqueous solution of hcl 30 vol.% for 3 min. finally, the etching of samples was done for 30 seconds in an aqueous solution of hcl 20 vol.% at 50 °c. in the following, rotating bending fatigue tests carried out on samples. the fatigue fracture surfaces were examined by scanning electron microscopy (sem). fatigue test results showed an increase in the fatigue strength of pretreated samples compared to that of the base metal. reducing the roughness of the surface caused by the pretreatment operation was responsible for this behavior. according to sem observations, the pretreatment process influenced the crack initiation stage, which eventually resulted in a better performance in the fatigue strength.