新型Ni-Cr基GH648合金成分对热力学平衡相析出行为的影响

Thermodynamic Calculation of Precipitation Phases in a High-Cr GH648 Superalloy

通过热力学平衡相计算方法并采用相应的Ni基数据库,对1种新型高铬的Ni-Cr基GH648合金成分对平衡相析出的影响规律进行系统研究。结果认为GH648合金析出的主要平衡相为α-Cr,γ′相和M23C6碳化物(主要为Cr23C6),并进一步计算了合金成分对这些相的析出行为及合金初熔点和终熔点的影响规律。计算结果表明,Cr含量主要影响α-Cr的析出量及开始析出温度,并影响合金的初熔点,对以Cr为主的M23C6的析出行为没有明显影响。C显著影响碳化物的析出量,而Al,Ti增加显著增加γ′相的析出量和开始析出温度。

The influence of chemical composition on equilibrium precipitation phases in a high-Cr GH648 super-alloy has been studied using a thermodynamic calculation method. Main equilibrium precipitation phases are alpha-Cr, gamma and M23C6 carbide phases. The calculation results show that Cr content significantly increases alpha-Cr mole fraction and incipient precipitating point, also affects incipient melting point, while only slightly affects M23C6 precipitation behavior. C content obviously increases M23C6 carbide precipitation, the effect of Al and Ti contents focuses on gamma phase.