The effect of inclusion factors on fatigue life and fracture-mechanics-based life method for a P/M superalloy at elevated temperature

•The effects of inclusions on fatigue life of FGH96 were investigated at 600 °C.•The scatter of inclusion-induced fatigue life is interpreted from fracture mechanics.•A unified maximum SIF calculation method is proposed for different types of crack.•Life is calculated by fracture mechanics for various inclusion sizes and positions.