Low‐cycle fatigue life prediction of powder metallurgy superalloy considering characteristic parameters of inclusions

Abstract

Foreign non‐metallic inclusions can significantly reduce the low‐cycle fatigue (LCF) life of powder metallurgy (PM) superalloy and greatly affect the safety and reliability of aeroengines. In this paper, LCF experiments on PM FGH96 superalloy with and without inclusions were conducted. Effects of inclusions on the fatigue life and damage mechanism of FGH96 alloy are discussed by fractography analysis. Parameters related to inclusion characteristics such as strength–inclusion coefficient are proposed. By introducing characteristic parameters of inclusions, the LCF life prediction models are established based on the Manson–Coffin relationship, which significantly improved the prediction accuracy and reduced the scattering band by a factor of 2.