700℃超超临界转子用镍基617合金的动态再结晶行为

Dynamic recrystallization behavior of nickel-base alloy 617 for 700 ℃ ultra-super-critical rotors

用Gleeble-3500热模拟机对镍基617合金进行等温热压缩试验,获得了不同变形条件下该合金的真应力-真应变曲线,并对压缩试样的微观组织进行分析。通过对试验数据的计算,得到了镍基617合金的动态再结晶激活能和本构关系方程;建立了动态再结晶图,获得了镍基617合金发生动态再结晶所需的临界变形量与Z参数的关系。结果表明,变形参数对镍基617合金热变形后的显微组织具有重要影响,较高的变形温度和较低的应变速率有利于动态再结晶的发生。

Isothermal compression tests of nickel-base alloy 617 were performed on Gleeble-3500 thermal simulator. A series of true stress-strain curves under different deformation conditions were measured and the microstructure of the alloy after hot compression deformation was investigated. By the calculations of the data, the dynamic recrystallization activation energies and the constitutive equation of nickel-base alloy 617 were obtained, the dynamic recrystallization diagram of nickel-base alloy 617 was established and the relationship between the parameter Z and critical strain for dynamic recrystallization was discussed. The results show that deformation parameters have important influences on microstructure of nickel-base alloy 617. The lower strain rate at higher deformation temperature benefits the dynamic recrystallization.