南京航空航天大学学报2025，Vol.57Issue(2)：327-336,10.DOI:10.16356/j.1005-2615.2025.02.014
热腐蚀对K444合金高周疲劳的影响研究
Effects of Thermal Corrosion on High Cycle Fatigue Strength of K444 Alloy
摘要
Abstract
This article focuses on the problem of high cycle fatigue(HCF)failure of gas turbine blades caused by hot corrosion.NaCl+Na2SO4 salt mixture is used for hot corrosion of K444 alloy for turbine blades.The microstructure,composition,and hardness of the hot corrosion layer are studied using SEM,EDS,and nanoindentation.The effect of hot corrosion on the HCF strength of K444 alloy is studied based on the stepwise loading method.The research results indicate that hot corrosion causes oxidation and sulfurization of the K444 alloy,with the sulfurization layer located below the oxidation layer,and there is a γ′ depletion zone in the matrix adjacent to the sulfurization layer.As the duration of hot corrosion increases,the oxide layer gradually thickens,and the thickness of the sulfide layer shows a trend of first increasing and then decreasing.The hardness order obtained from nanoindentation analysis is the oxide layer>matrix>sulfide layer.Hot corrosion accelerates the initiation of fatigue cracks in K444 alloy,resulting in a decrease of fatigue strength of K444 alloy notched specimens by 9.68%—23.97%.关键词
镍基高温合金/氧化/热腐蚀/高周疲劳/裂纹萌生Key words
Ni-based superalloys/oxidation/hot corrosion/high cycle fatigue(HCF)/crack initiation分类
数理科学引用本文复制引用
李明亮,贾旭,凌晨,于连旭,于苏洋,江荣,宋迎东..热腐蚀对K444合金高周疲劳的影响研究[J].南京航空航天大学学报,2025,57(2):327-336,10.基金项目
航空发动机及燃气轮机基础科学中心重大项目(P2022-A-Ⅲ-003-001) （P2022-A-Ⅲ-003-001）
江苏省优秀青年基金(BK20220136). （BK20220136）
