航空材料学报2025，Vol.45Issue(4)：67-76,10.DOI:10.11868/j.issn.1005-5053.2025.000035
Hf对K4222高温合金组织和高温持久性能的影响
Effect of Hf on microstructure and high temperature stress rupture properties of K4222 superalloy
摘要
Abstract
The high-temperature mechanical properties of cast nickel-based superalloy K4222 enhance through alloying of Hf.This work investigates the effect of adding mass fraction of 0.72%and 1.5%Hf on the microstructure and high-temperature stress rupture properties of the alloy.The results reveal that the addition of Hf not only increases the MC carbide content in the alloy,but also facilitates the formation of eutectic(Ni5Hf+γ)phases.After heat treatment,M23C6 carbides are dissolved at high temperature and MC carbides are degraded,resulting in an overall reduction in the carbide content of each alloy and the elimination of eutectic phases.However,a small amount of Ni5Hf phase remains in the 1.5%Hf alloy.Meanwhile,the results show that Hf can greatly improve the stress rupture life of the alloy.Compared with 0%Hf alloy,the stress rupture life of the 0.72%Hf and 1.5%Hf alloys increases 101.4%and 211.2%under the condition of 899℃/172 MPa,respectively.The improvement of Hf content will reduce the rupture plasticity of K4222 alloy to a certain extent,but 0.72%Hf still maintains good level.Further analysis shows that the addition of Hf can change the morphology of carbides,increase the grain boundary strength,reduce the occurrence of carbide cracking and intergranular cracks,and thus improve the high-temperature creep strength of the alloy.关键词
高温合金/Hf/组织/高温持久性能/合金元素作用Key words
superalloy/Hf/microstructure/high-temperature stress rupture properties/alloy element effect分类
航空航天引用本文复制引用
胡聘聘,王佳月,李妍佳,李文道,肖程波..Hf对K4222高温合金组织和高温持久性能的影响[J].航空材料学报,2025,45(4):67-76,10.基金项目
国家自然科学基金(52201024) （52201024）
湖南省自然科学基金(2022JJ40441) （2022JJ40441）
