丁智平王腾飞李明陈吉平
材料研究学报
在680和850℃下对DD3镍基单晶合金进行多轴非比例加载低周疲劳试验, 结果表明等效应变范围Δεe、试验温度、等效应力范围Δσe对单晶合金的低周疲劳寿命有显著影响。基于能量耗散理论, 引入参量k表征多轴非比例加载对疲劳寿命的影响, 构造循环塑性应变能作为损伤参量, 建立镍基单晶合金低周疲劳寿命预测模型。参量k与循环寿命之间呈幂函数关系。根据镍基单晶合金的微观尺度结构特征, 建立γ/γ'双相单胞有限元模型, 进行多轴非比例循环加载应力应变数值模拟。根据宏观有限元模型和γ/γ'双相单胞微观有限元模型的计算结果, 以及镍基单晶合金680和850℃低周疲劳试验数据, 对疲劳寿命模型进行多元线性回归分析, 结果表明微观单胞有限元模型的分析精度比宏观有限元模型显著提高,两种温度下的试验数据分别落在1.6倍和2.0倍偏差分布带内。
关键词:
金属材料
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low cycle fatigue
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single crystal superalloy
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multiaxial non-proportional loading
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unit cell model
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life prediction
姚俊
,
郭建亭
,
袁超
,
李志军
金属学报
研究了抗热腐蚀铸造镍基高温合金K52在室温和900℃的低周疲劳行为。对循环应力—应变数据和应变—疲劳寿命数据进行了分析, 给出了K52合金在此温度下的疲劳参数。合金的循环应力响应行为在室温下呈现循环硬化, 而在900℃时则呈现循环软化, 原因在于循环形变过程中位错之间以及位错与析出相之间的相互作用。疲劳断口宏观和微观分析表明：裂纹主要萌生于试样表面或靠近表面的缺陷处；裂纹形成后垂直于加载轴方向扩展, 试样呈穿晶断裂。
关键词:
K52合金
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low cycle fatigue
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cyclic stress response
Author H.J. Shi1)
,
S.L. Liu2)
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Y.H. He1) and Z.X. Duan2) 1) Department of Engineering Mechanics
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Tsinghua University
,
Beijing 100084
,
China2) Laboratory of Material Mechanical Properties
,
Beijing Institute of Aeronautical Materials
,
Beijing 100095
,
ChinaManuscript received 18 October 1998
金属学报(英文版)
A series of low cycle fatigue and creepfatigue tests on smooth specimens and notched specimens were performed with a high temperature alloy used in the manufacture of aeroengine turbine discs. The cyclic stressstrain behavior and fracture characteristics of the notched specimens were emphatically investigated. A comparison of fatigue behavior between smooth and notched specimens was done and lifetime of notched specimens was evaluated. At the same temperature, the fatiguecreep lives of the smooth specimens are far greater than that of the notched specimens.
关键词:
low cycle fatigue
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null
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null
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null
M. Zhao
,
L.Y. Xu
,
K.S. Zhang
金属学报(英文版)
Low cycle fatigue tests on nickel base superalloy GH536 were performed at 600. 700and 800°C. The strain-life and cyclic stress-strain relationship were given at various temperatures. The change in fatigue life behavior and fatigue parameters with temperature increasing was discussed. At low and intermediate total strain amplitudes,the fatigue life was found to decrease with increasing temperature.
关键词:
low cycle fatigue
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null
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null
J.H. Tundermann(Inco Alloys International
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Inc.
,
Huntington
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WV 25705
,
USA Manuscript received 26 August 1996)
金属学报(英文版)
Many gas turbine components are made from nickel alloy sheet. Most are used for directing or containing gases at high temperatures and pressures where metal temperatures can be as high as 1090℃ (2000°F). These applications included combustor systems, casings and liners, transition and exhaust ducting, afterburners, and thrust reversere. Light weight components and sub-assemblies call for alloy sheet with high levels of stength and oxidation resistance. Complex component design calls for excellent ductility and ease of fabrication.The wide range of nickel alloy sheet alloys presently used in aircraft and land-based gas turbines is briefly described and typical properties presented. New sheet alloy developments, involving INCONEL~* alloys 625LCF, 718SPF and MA754, are presented including the process routes involved and material properties.
关键词:
:aerospace
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null
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null
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null
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null
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null
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null
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null
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null
杨雄飞
,
Surajit Kumar Paul
,
Pritam Kumar Rana
,
Debdulal Das
,
Sanjay Chandra
,
Saurabh Kundu
钢铁钒钛
doi:10.7513/j.issn.1004-7638.2015.02.008
通过试验研究,对比分析了微合金化和余热处理带肋钢筋的高周疲劳和低周疲劳性能.研究表明,微合金化钢筋比余热处理钢筋具有更好的疲劳性能.在微合金化和余热处理带肋钢筋的高低周疲劳试验中,观察到在横肋根部裂纹萌生并沿该区域扩展.有限元模拟结果显示在横肋根部出现应力集中,应力三轴度变大.模拟过程中也发现在横肋根部拉应变累积.有限元模拟结果有助于解释试验观察结果,即疲劳裂纹沿热轧带肋钢筋的横肋根部萌生及扩展.
关键词:
余热处理钢筋
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微合金化钢筋
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高周疲劳
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低周疲劳
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抗震性能
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应力集中
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应力三轴度
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横肋
PENG Kaiping CHEN Wenzhe OIAN Kuangwu Fuzhou University
,
Fuzhou
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China teaching assistant
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Department of Mechanical Engineering
,
Fuzhou University
,
Fuzhou 350002
,
China
金属学报(英文版)
Studies were made of the symmetric tensile-compressive low cycle fatigue behaviour and the influence of dynamic strain aging(DSA)pre-treatment of 18-8 austenitic stainless steel. Within the testing amplitude range of strain.±0.5 % to±1.5 %,the three processes of cyclic hardening,cyclic saturation and cyclic softening were observed.In the same amplitude of strain,the peak stress of the samples pre-treated by DSA is higher than that of solid-solu- tion and cold working pre-treatment,but no remarkable differences of the fatigue lives of them were found.TEM observation shows that the uniform and stable dislocation networks with high density form after DSA pre-treatment,which increases the cyclic peak stress.The cyclic softening results from the low dislocation density and elongated cell structure with low energy.
关键词:
18-8 austenitic stainless steel
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null
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null
