【摘要】 利用微观组织分析及化学相分析的方法研究了9种不同Mo、W含量的汽轮机叶片用GY200镍基合金中碳化物及γ’强化相的析出规律。结果表明,合金中出现MC、M₆C、M₂₃C₆型碳化物,MC相由一次未溶TiC和少量二次析出的TiC组成,MC相含量随W、Mo添加量增加而增加。M₆C在1080℃就开始析出,对于GY200镍基合金,M₆C析出条件可由Cr/（Cr+Mo+0.7W）≤0.847（at%）经验公式来表达。Mo添加后,M₂₃C₆含量随W添加量的增加有减少趋势。Mo促进TCP相析出的动力学比W元素的要强,利用W来替代部分Mo,能够减少Laves相、TCP相的析出。W添加4%以内将明显改善合金高温强塑性。更多还原

【Abstract】 The precipitation behavior of carbides and gamma prime phase in GY200 nickel-based alloys for blade with different contents of tungsten and molybdenum was investigated by using microstructure and chemical phase analysis.The results show that the carbides of these alloys are MC,M₆C and M₂₃C₆.MC phase is composed of two kinds of TiC phases,the undissolved and secondary precipitated TiC particles,and the amount of MC phase increases with the increasing of W and Mo addition.The solution temperature of M₆C phase in the GY200 alloys is 1080 ℃,and the empirical formula describing the precipitation of M₆C can be expressed as Cr/（ Cr + Mo + 0.7W） ≤0.847（ at%）.The amount of M₂₃C₆ phase decreases with the increasing of the W content.Kinetics of thermodynamic calculation show that Mo can promote TCP phase more effectively than W element,and the use of W to replace part of Mo can reduce the precipitation of Laves phase and TCP phase.When the amount of W is less than 4%,the high temperature strength and plasticity of the alloy will be improved obviously.更多还原