δ相对镍基高温合金GH4169低周疲劳行为的影响
发布时间：2018-09-14 19:48
【摘要】：镍基高温合金因其具有较高的高温强度、抗氧化性能及抗疲劳和蠕变等性能,在航空发动机关键热端部件中有着广泛的应用。但我国高温合金在航空发动机中的应用技术还不是很成熟,原因之一是对国产高温合金微观结构、组成相与其性能之间的关联还缺乏比较系统的认识。基于以上的问题,本文对国产涡轮盘用材料GH4169合金进行了不同热处理,重点研究了δ相含量对拉伸和低周疲劳行为的影响。主要内容和结论如下：(1)采用三种不同的热处理工艺对GH4169合金进行热处理,合金的显微组织受热处理参数的影响较大。热处理后,合金的组织中析出了不同含量的δ相。(2)对常温拉伸试验的研究表明,合金的拉伸行为明显受到6相的影响。随着6相含量的增加,合金的抗拉强度减小而延性增加。拉伸断口的形貌因6相含量的不同也存在一些差异。(3)GH4169合金的常温低周疲劳寿命基本不受δ相的影响,不同6相含量的合金具有相近的疲劳寿命。合金Coffin-Manson关系的塑性线具有双斜率特征。同时,本文对合金的循环变形行为、断裂方式和变形机理进行了相应的分析。(4)GH4169合金在650℃下的低周疲劳寿命在高应变幅(Aεt/20.6%)下基本不受δ相含量的影响；在较小应变幅下(△εt/2=0.5%)的疲劳寿命具有一定的分散性,并随着6相含量的增加而增加。合金Coffin-Manson关系的塑性线不具有双斜率特征。
[Abstract]:Nickel-based superalloys have been widely used in aero-engine because of their high temperature strength, oxidation resistance, fatigue resistance and creep resistance. However, the application technology of superalloy in aeroengine in China is not very mature, one of the reasons is the lack of a systematic understanding of the relationship between the microstructure, phase composition and properties of domestic superalloys. Based on the above problems, different heat treatment was carried out on the GH4169 alloy, a domestic material for turbine disk, and the effect of 未 phase content on tensile and low cycle fatigue behavior was studied. The main contents and conclusions are as follows: (1) the microstructure of GH4169 alloy is greatly affected by heat treatment parameters by using three different heat treatment processes. After heat treatment, 未 phases with different contents were precipitated in the microstructure of the alloy. (2) the tensile behavior of the alloy was obviously affected by the 6 phases in the tensile test at room temperature. With the increase of 6 phase content, the tensile strength decreases and the ductility increases. (3) the low cycle fatigue life of GH4169 alloy at room temperature is not affected by 未 phase, and the fatigue life of the alloy with different content of 6 phases is similar. The plastic line of Coffin-Manson relation of alloy has double slope characteristic. At the same time, the cyclic deformation behavior, fracture mode and deformation mechanism of GH4169 alloy are analyzed. (4) the low cycle fatigue life of GH4169 alloy at 650 鈩，
本文编号：2243697
[Abstract]:Nickel-based superalloys have been widely used in aero-engine because of their high temperature strength, oxidation resistance, fatigue resistance and creep resistance. However, the application technology of superalloy in aeroengine in China is not very mature, one of the reasons is the lack of a systematic understanding of the relationship between the microstructure, phase composition and properties of domestic superalloys. Based on the above problems, different heat treatment was carried out on the GH4169 alloy, a domestic material for turbine disk, and the effect of 未 phase content on tensile and low cycle fatigue behavior was studied. The main contents and conclusions are as follows: (1) the microstructure of GH4169 alloy is greatly affected by heat treatment parameters by using three different heat treatment processes. After heat treatment, 未 phases with different contents were precipitated in the microstructure of the alloy. (2) the tensile behavior of the alloy was obviously affected by the 6 phases in the tensile test at room temperature. With the increase of 6 phase content, the tensile strength decreases and the ductility increases. (3) the low cycle fatigue life of GH4169 alloy at room temperature is not affected by 未 phase, and the fatigue life of the alloy with different content of 6 phases is similar. The plastic line of Coffin-Manson relation of alloy has double slope characteristic. At the same time, the cyclic deformation behavior, fracture mode and deformation mechanism of GH4169 alloy are analyzed. (4) the low cycle fatigue life of GH4169 alloy at 650 鈩，
本文编号：2243697
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