热处理对GH4169合金组织及低周疲劳寿命的影响

摘要

采用三种热处理工艺对GH4169合金进行处理,研究了处理后合金相应的显微组织以及在应变幅1.0%,0.8%和0.5%下的常温低周疲劳性能.结果表明:采用三种工艺热处理后,GH4169合金的组织中均析出了δ相,热处理前后的晶粒尺寸相差较小;在固溶和双时效处理之间增加了900℃固溶处理后,δ相在合金中的析出量增加,且保温时间长的δ相含量更多;GH4169合金的疲劳寿命几乎不受δ相析出量的影响,其疲劳断口在相同应变幅下都呈现出相似的形貌,裂纹源数量均随着应变幅的增加而增多.%The GH4169 alloy was treated using three heat treatment processes and the corresponding microstructures and the low cycle fatigue properties at the strain amplitude of 1.0%,0.8% and 0.5% at room temperature were studied.The results show that theδphase was precipitated in the microstructure of GH4169 alloy after the three heat treatments.The grain sizes before and after heat treatment had little difference.When adding a 900 ℃ solution treatment between solution and two-step aging treatments,the amount ofδphase precipitation in the alloy increased and moreδphases were obtained with longer holding time.Theδphase amounts almost had no influences on the fatigue lives of the GH4169 alloy.And the fatigue fracture surface at the same strain amplitude exhibited similar morphology.The number of crack sources increased with the increase of strain amplitude.