摘要
对经过固溶+双时效热处理后的GH4169镍基高温合金进行650℃高温低周疲劳试验,研究了不同应力幅(550,600,650 MPa)下的循环响应特性,并观察了疲劳断口和二次裂纹形貌,分析了不同应力幅下的损伤机理。结果表明:不同应力幅下试验合金均表现出循环软化特性,且随着应力幅的增加,循环软化程度增强;当应力幅为550 MPa时,裂纹的扩展模式为穿晶扩展,二次裂纹主要在夹杂物和滑移带处萌生;当应力幅为650MPa时,裂纹的扩展模式为穿晶-沿晶混合扩展,二次裂纹主要萌生于晶界和滑移带处;试验合金的变形机制由低应力幅时的平面滑移向高应力幅的交滑移转变。
Low cycle fatigue tests at elevated temperature of 650℃ were conducted on GH4169nickel-based superalloy after solid solution and double aging treatments.The cyclic response characteristics at different stress amplitudes(550,600,650 MPa)were studied.The morphology of fatigue fracture and secondary cracks was observed.The damage mechanism at different stress amplitudes was analyzed.The results show that the tested alloy showed cyclic softening characteristics at different stress amplitudes,and the degree of softening increased with the increase of stress amplitude.The crack propagation showed the transgranular propagation mode at the stress amplitude of 550 MPa,and the secondary cracks were mainly generated at inclusions and slip bands.When the stress amplitude reached 650 MPa,the crack propagation mode became transgranular-intergranular mixed propagation,and the secondary cracks were mainly generated at grain boundaries and slip bands.The deformation mechanism of the tested alloy changed from planar slip at a low stress amplitude to cross slip at a high amplitude.
作者
王磊
刘颜铭
陈刚
刘俊
WANG Lei;LIU Yanming;CHEN Gang;LIU Jun(Department of Mechanical and Electrical Engineering,Shenyang Aerospace University,Shenyang 110136,China;School of Chemical Engineering and Technology,Tianjin University,Tianjin 300072,China;Metallurgical Equipment Branch of North Heavy Industry Group Co.,Ltd.,Shenyang 110141,China)
出处
《机械工程材料》
CAS
CSCD
北大核心
2019年第1期45-49,共5页
Materials For Mechanical Engineering
基金
东北大学航空动力装备振动及控制教育部重点实验室研究基金资助项目(VCAME201701)
