固溶+时效对GH4169合金交替腐蚀疲劳性能的影响

Effect of Solid Solution and Aging on Alternating Corrosion Fatigue Properties of GH4169 Alloy

GH4169超级合金是一种用于制造航空发动机压气机叶片的重要金属材料。对GH4169合金固溶时效热处理后,分析该材料的组织、显微硬度、交替腐蚀疲劳和间歇疲劳等性能。结果表明：GH4169经固溶＋时效处理后,从γ相中析出了大量γ＇相、γ＇相、δ相以及碳化物,其平均显微维氏硬度由287.9 HV增加到432.8 HV;随着腐蚀时间的增加,表面点蚀坑增多,促进了多疲劳源产生,交替腐蚀疲劳寿命逐渐降低;而在腐蚀和疲劳交替作用过程中,腐蚀液中的Cl、K离子渗入材料疲劳源附近区域,进一步降低了GH4169的腐蚀疲劳寿命。此外,间歇疲劳寿命大于交替腐蚀疲劳寿命。

The GH4169 super alloy is an important metal material used in the manufacture of aero-engine compressor blades. The microstructure, microhardness, alternating corrosion fatigue and intermittent fatigue of GH4169 alloy after solution＋aging treatment were analyzed. The result shows that, a lot of γ′ phase, γ″ phase, δ phase and carbides from γ phase precipitate after solution＋aging treatment ofGH4169. The average Vickers hardness increases from 287.9 HV to 432.8 HV. With the increase of corrosion time, the number of pitting pits on the surface increases, which promotes the generation of multiple fatigue sources and decreases the fatigue life of alternating corrosion. In the process of alternating corrosion and fatigue, the C1, K ions in the corrosion solution infiltrate into the region near the fatigue source of the material, which further reduces the corrosion fatigue life of GH4169. In addition, the intermittent fatigue life is longer than the alternating corrosion fatigue life.