中文摘要：

利用场发射扫描电子显微镜对其铸态组织进行了观察,并通过热力学计算,对该合金中成分对平衡相析出的影响规律进行了研究。结果表明,эк151合金凝固过程中,Mo、Nb和Ti等元素在枝晶间偏析,并形成大量γ′＋γ共晶相。合金主要析出相为大量的γ′相、少量的一次、二次碳化物和硼化物以及μ相。其中强化相γ′多成立方状,800℃下平衡态质量分数含量高达50%左右。当成分在规定范围波动时,对熔点影响最大的为Cr、Mo、Nb和Ti;而Al、Ti和Nb含量变化均会影响到γ′相的析出量及析出温度;Cr、Mo含量变化还会影响到二次碳化物的种类,Ti、Nb、C虽然是一次碳化物MC的主要形成元素,但是成分范围内对其析出温度影响并不明显。影响μ相析出温度和析出量的主要成分为Cr、Mo和W。

英文摘要：

The cast microstructure of a new difficult-to-deform superalloy эк151, was observed by high resolution field emission scanning electron microscope. The effects of elements on the thermodynamic equilibrium phases were studied by Thermo-Calc software. The results show that there is serious segregation of Mo, Nb and Ti during the solidification, which promotes γ′＋γ eutectic. The main precipitates of эк151 alloy are a large fraction of cubic γ′, some carbides, borides and μ phase. Higher Cr, Mo, Nb and Ti contents can improve the primary and final melting points. The contents of Al, Ti and Nb can influence the precipitation temperature and mass fraction of γ＇ phase. Contents of Cr and Mo promote precipitation of M 23 C 6 and M 6 C respectively. Furthermore, the increment of Cr, Mo and W content leads to more precipitation of μ phase.