K418B合金900℃长期时效显微组织和力学性能演变  

Microstructure and Mechanical Properties Evolution of K418B Alloy at 900℃ for a Long-Term Aging

作　　者：张楚博 骞磊 张明军 张丽辉 ZHANG Chu-bo;QIAN Lei;ZHANG Ming-jun;ZHANG Li-hui(Beijing Institute of Aeronautical Materials,Beijing 100095,China)

机构地区：[1]中国航发北京航空材料研究院,北京100095

出　　处：《铸造》2024年第3期357-363,共7页Foundry

摘　　要：研究了900℃长期时效对K418B合金的显微组织以及力学性能的影响。采用热力学计算软件JMatPro对合金中相的稳定性及体积百分比进行计算。借助扫描电镜及附带的能谱仪对显微组织及成分进行分析。使用Image-Pro Plus软件对碳化物和γ′相的尺寸以及体积分数进行统计分析。结果表明:随着时效时间的增长,室温拉伸强度σ_(b)和σ_(0.2)逐渐下降,塑性变化不明显;750℃高温下的拉伸性能与室温拉伸的变化规律相同,σ_(b)和σ_(0.2)随着时效时间的增长,总体呈现下降趋势,塑性的变化规律不明显;760℃/530 MPa持久寿命逐渐下降,塑性逐渐上升。982℃/152 MPa持久寿命随着时效时间的增长,持久寿命呈现下降趋势,持久塑性的变化是随着时效时间的增长,塑性得到明显的提升。长期时效后由于组织发生变化导致材料强度逐步降低,材料塑性呈现上升的趋势。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 andγ′phase were statistically analyzed by Image Pro Plus software.The results indicate that as the aging time increases,the room temperature tensile strengthσ_(b) andσ_(0.2) gradually decreases,and the plastic change is not significant.The tensile properties at 750℃are the same as those at room temperature,σ_(b) andσ_(0.2) 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 at982℃/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 

分 类 号：TG132.32[一般工业技术—材料科学与工程]