南京工业大学学报（自然科学版）2025，Vol.47Issue(6)：660-667,8.DOI:10.3969/j.issn.1671-7627.2025.06.005
GH4698高温合金蠕变性能及损伤机制
Creep properties and damage mechanisms of GH4698 superalloy
摘要
Abstract
High-temperature creep performance is a critical indicator for evaluating GH4698 superalloy and assessing its long-term stability in high-temperature environments.In this study,forged GH4698 samples underwent standard heat treatment,and creep tests were performed at 750℃ under different stress levels(300,350,400,and 450 MPa)to investigate their creep behavior.The microstructural evolution during creep was also analyzed.The results indicate that the creep life of GH4698 superalloy increases dramatically as the applied stress decreases.At 750℃,lower stress and longer creep durations lead to coarsening of small γ' precipitates through mutual engulfment,causing a continuous decrease in the fraction of small γ' and an increase in the fraction of large γ',while the total γ'content remains nearly constant.Transmission Electron Microscopy(TEM)analysis indicates that dislocations shear through small γ' precipitates,whereas they bypass large γ' precipitates via the Orowan mechanism.Consequently,γ' coarsening during creep significantly degrades the alloy's mechanical properties.Additionally,extensive precipitation and growth of M23 C6 carbides along grain boundaries reduce boundary strength,induce microcracks,and combined with oxidation,promote crack propagation along grain boundaries.关键词
GH4698高温合金/蠕变行为/高温蠕变机制/组织演变/损伤机制/位错机制Key words
GH4698 superalloy/creep behavior/high-temperature creep mechanism/microstructure evolution/damage mechanism/dislocation mechanism分类
矿业与冶金引用本文复制引用
吴双,姜勇,王小威,巩建鸣..GH4698高温合金蠕变性能及损伤机制[J].南京工业大学学报（自然科学版）,2025,47(6):660-667,8.基金项目
国家重点研发计划(2022YFF0605600) （2022YFF0605600）
