K447A合金双性能整体叶盘的显微组织和力学性能  

Microstructure and mechanical properties of doubled-properties integral turbine disk of K447A alloy

作　　者：李相辉[1] 李炼 张勇[1] 汤鑫[1] 谷怀鹏[1] 盖其东[1] 

机构地区：[1]北京航空材料研究院先进高温结构材料重点实验室,北京100095 [2]中航工业南方航空工业集团有限公司,湖南株洲412002

出　　处：《材料热处理学报》2013年第S2期128-133,共6页Transactions of Materials and Heat Treatment

摘　　要：研究了K447A合金双性能整体叶盘的显微组织和力学性能。结果表明,叶盘的铸态组织均包括γ基体、MC型碳化物、γ/γ'共晶、γ'相和Ni5Hf相。随着固溶温度的升高(1185℃→1230℃),合金等轴晶和定向柱晶试样的抗拉强度和持久寿命提高;增加高温时效处理(1185℃/4 h)可显著改善等轴晶的拉伸塑性和定向柱晶的持久寿命。热处理后,轮盘和叶片中的γ'相体积分数达到61%。碳化物发生"碎化",且由γ'相包覆,同时沿晶界还析出了链状的MC型碳化物。切取性能测试结果表明,叶盘室温抗拉强度不小于987 MPa,760℃/724 MPa下的持久寿命不低于11.5 h。The microstructure and mechanical properties of doubled-properties integral turbine disk of K447A alloy were investigated. The results revealed that as-cast microstructure of the alloy is composed of γ matrix,γ' phase,γ/γ' eutectic,MC carbide and Ni 5 Hf phase. With the solid solution temperature increasing,the tensile strength and stress rupture life of the alloy increased. The elongation of the alloy with equiaxed structure and the stress rupture life of the alloy with directionally solidified structure increased after the high temperature aging treatment. After the heat treatment,the volume fraction of γ' phase is up to 61%. Meanwhile,the MC carbides phases 'fragmented'and are surrounded by γ' phases. Furthermore,MC carbides with chain structure also precipitated along grain boundaries. The investigation of mechanical properties obtained directly from the integral turbine disk suggested that the tensile strength at room temperature and the stress rupture life under the condition of 760 ℃/7240 MPa are not less than 987 MPa and 11. 5 h.

关 键 词：K447A合金 双性能整体叶盘 显微组织 热处理 力学性能 

分 类 号：V232.3[航空宇航科学与技术—航空宇航推进理论与工程]