In the present study,the effects of long-term aging at 900℃ have been investigated on microstructure and mechanical properties of K418B superalloy.The phase stability and volume fraction of the alloy were simulated by JMatPro.The samples were observed by scanning electron microscope(SEM).The microstructure was analyzed by energy dispersive X-ray spectrometer(EDS).The size and volume fraction of carbide and γ'phase were statistically analyzed by Image Pro Plus software.The results indicate that as the aging time increases,the room temperature tensile strength σb and σ0.2 gradually decreases,and the plastic change is not significant.The tensile properties at 750 ℃ are the same as those at room temperature,σb and σ0.2 shows an overall downward trend as the aging time increases.The variation pattern of plasticity is not obvious;The stressrupture life of 760 ℃/530 MPa gradually decreases,and the plasticity gradually increases.The stressrupture at 982 ℃/152 MPa shows a decreasing trend with the increase of aging time,and the change in stressrupture plasticity is a significant improvement with the increase of aging time.After long-term aging,the strength of the material gradually decreases due to changes in the microstructure,and the plasticity of the material shows an upward trend.
关键词
镍基高温合金/K418B/长期时效/显微组织/力学性能
Key words
nickel super alloy/K418B/long-term aging/microstructure/mechanical properties
维普
万方数据