Fatigue characteristics of nitrided SACM 645 according to the nitriding condition and notch

This study was performed in order to investigate the fatigue characteristics of nitrided SACM 645 steel according to the nitriding condition and notch shape. V-notches were made on the specimens and they were nitrided using the Nitemper method. The rotary bending fatigue test for each specimen was carried out at room temperature. The fatigue characteristics of the nitrided specimen improved compared with those of the non-nitrided specimen because of compressive residual stress on the surface. The improvement of the fatigue characteristics of the notched specimen was more effective than the smooth one.