Evaluation of the influence of surface crack-like defects on fatigue life for a P/M nickel-based superalloy FGH96

•Specimens containing different artificial defects sizes were tests at RT and ET.•Fatigue life decreases significantly due to the existence of artificial defects.•The life scatter of specimen with similar defect under same condition is small.•A fracture-mechanic based model was proposed to evaluate the existence of a defect.