High-cycle fatigue of Ni-base superalloy Inconel 713LC

Fatigue strength of three nominally identical batches of cast Ni-base superalloy Inconel 713LC under load symmetrical cycling and cycling with tensile mean load was experimentally determined in high-cycle fatigue region at a temperature of 800 °C in air. Examination of fracture surfaces, crack initiation sites, microstructure and casting defects has been performed. Statistical method of largest extreme value distribution has been applied to characterize the casting defect distribution. The aim of the study was to evaluate the mean stress effect on high-cycle fatigue life, to explain the scatter of fatigue life data and a scatter related to material produced under nominally identical production conditions.