STABILITY OF MICROSTRUCTURE AND MECHANICAL PROPERTIES OF A Ni-BASED SUPERALLOY FOR ADVANCED ULTRA-SUPERCRITICAL FOSSIL POWER
Optical microscopy(OM),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and thermodynamic calculations were employed to study the microstructural stability of a new Ni-based alloy(Ni-Cr-Fe-W-Al)designed for advanced ultra-supercritical power plants.Tensile properties and stress-rupture strength were also investigated.The thermodynamic calculation illustrates that the main phases during 700-800℃ were γ,M23C6,M3B2 and P phase.The experimental results show that the main precipitates after standard heat treatment were M23C6 and γ phase.The average size and the volume fraction of γ phase were approximately 23nm and 15%,respectively.P-phase predicted by thermodynamic calculation was not identified in specimens isothermally aging at 700-800℃,and the coarsening behavior of γ followed the Ostwald model.Room temperature micro-hardness(Hv0.5)deceased with the increasing isothermal temperature.The room temperature tensile strength increased obviously with the elongation and reduction of area decreasing after aging at 760℃.The tested samples show high impact properties during prolonged exposure at 700-800℃ for 1000h.Stress-rupture tests show that Ni-Cr-Fe-W-Al alloy exhibited high stress-rupture strength at 700-750℃.
Ni-based superalloy solution annealing γ phase tensile properties
Xianchao Hao Long Zhang Xiujuan Zhao Chao Xiong Tian Liang Yingche Ma Kui Liu
Institute of Metals Research,Chinese Academy of Sciences 72 Wenhua Road Shenhe District,Shenyang City,Liaoning,110016,P.R.C.
国际会议
Energy Materials 2014(第一届能源材料国际会议)
西安
英文
235-241
2014-11-04（万方平台首次上网日期，不代表论文的发表时间）