材料期刊网

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M23C6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.

The thermodynamic simulation software of Thermo-Calc and JMatPro were used to investigate component optimization of nickelbased Nimonic 105 alloy and the new alloy design.The results show that by reducing the content of Co,Cr,and Mo element,the precipitation temperature of μ phase in Nimonic 105 alloy can be reduced effectively,at the same time it can also reduce the separation tendency of σ phase at 700 ℃ in the alloy.A new Ni-base alloy HR105C has been designed by adjusting the ratio of alloy elements in Nimonic 105 alloy.There are no harmful phases,such as σ phase and μ phase,in the new designed alloy at the range of 700-1200 ℃.At 700 ℃ the mole fraction of the balance precipitation of γ′ phase and M23C6 phase in the HR105C alloy are 32％ and 1％,respectively,while the precipitation of γ′ phase is slightly higher than that of in Waspaloy alloy.The persistent performance of the HR105C alloy is decreased significantly compared with the Nimonic 105 alloy,but at the same level of Waspaloy alloy and even slightly better than Waspaloy alloy.The HR105C alloy can satisfy the design requirement of materials used in high-temperature parts of thermal power turbine with 700 ℃ parameter.The optimization design has reached the expected purpose.In addition,the γ′ phase with small size in HR105C alloy has better persistent performance.Appropriate measures should be adopted to enhance the stability of γ′ phase in order to reduce the coarsening rate of γ′ phase,which can improve the persistent performance of HR105C alloy.