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运用Thermo-Calc和JMatPro热力学模拟软件对镍基Nimonic 105合金进行了成分优化以及新合金设计研究。研究表明,通过降低Co、Cr和Mo元素含量可有效降低Nimonic 105合金中μ相的析出温度,同时也可降低700℃时合金中σ相的析出倾向。通过调整Nimonic 105的部分合金元素配比设计了一种新型镍基合金HR105C。HR105C合金在700~1200℃区间无σ相和μ相等有害相。在700℃时HR105C合金中γ’相和M_(23)C_6相的平衡析出量的摩尔分数分别约为32%和1%,γ’相的析出略高于Waspaloy合金。HR105C合金的持久性能较Nimonic 105合金显著降低,但与Waspaloy合金相当,甚至可能略优于Waspaloy合金,可满足700℃参数火电汽轮机高温部件用材设计要求,达到了预期优化设计目的。另外,拥有小尺寸的γ’相的HR105C合金具有更好的持久性能。可采取措施通过提高γ’相的稳定性来减缓γ’相的粗化速率,进而使HR105C合金的持久性能得到提升。
Thermo-Calc and JMatPro thermodynamic simulation software were used to optimize the composition of Ni-based Nimonic 105 alloy and study the design of new alloys. The results show that the precipitation temperature of μ phase in Nimonic 105 alloy can be effectively reduced by reducing the contents of Co, Cr and Mo, and the precipitation tendency of σ phase in the alloy at 700 ℃ can also be reduced. A new type of Ni-based alloy HR105C was designed by adjusting the alloying elements of Nimonic 105. HR105C alloy in the 700 ~ 1200 ℃ range without σ phase and μ equivalent harmful phase. At 700 ℃, the equilibrated amounts of γ ’phase and M_ (23) C_6 phase in HR105C alloy were about 32% and 1%, respectively. The precipitation of γ’ phase was slightly higher than that of Waspaloy alloy. The durability of HR105C alloy is significantly lower than that of Nimonic 105 alloy, but comparable to that of Waspaloy alloy, and may even be slightly better than that of Waspaloy alloy. The HR105C alloy meets the design requirements of material for high temperature components of thermal power steam turbine at 700 ℃ and achieves the expected optimization design purpose. In addition, the HR105C alloy with the small size of the γ ’phase has better durability. Measures may be taken to slow down the coarsening rate of the γ ’phase by increasing the stability of the γ’ phase, thereby enhancing the durability of the HR105C alloy.