对核电工程材料(钛合金T42NG与T225NG和主螺栓材料18Cr2NiWA)开展了室温与350℃高温下的低周疲劳性能试验研究，获得了各材料单调R-O本构模型和M-C寿命估算模型。基于这些模型，研究了材料的循环强化与软化规律，研究了温度系数λσ，λΔσ和λNf对钛合金静强度、循环强度和低周疲劳规律的影响效应；根据温度对寿命的影响系数λNf与应变幅Δε/2呈线性规律的重要发现，提出了考虑温度效应的用于高温低周疲劳寿命估算的λ-M-C模型，进而总结出一种较现行方法更简便的高温疲劳试验方法。
A serial of tensional and low cycle fatigue tests for two kinds of titanium alloy :T42NG and T225NG and for 18Cr2NiWA steel at room temperature and 350℃ are carried out. Based on the test results, six monotonic constitutive relationships between stress and strain and six relationships between life Nf and strain amplitude controlled are given. By three ratio λσ，λΔσ and λNf of the materials related to the elevated temperature,The influence of the elevated temperature on both monotonic tensional intensity and cyclic intensity of the titanium alloys and on fatigue life of each material is systematically investigated. According to the important finding about a linearity relationship between the ratio λNf and strain amplitude Δε/2,a new model, or λ-M-C model for predicting the fatigue life of a exponential material under R=－1 and at an elevated temperature is presented. To get the λ-M-C model，the method that may simplify test and regression is discussed.
参考文献
| [1] | S S Manson .[J].Journal of Experiment Mechanics,1965,l5(07):193-226. |
| [2] | GB/T15248-1994.GB/T15248-1994.金属材料轴向等幅低循环疲劳试验方法[S].,1995-6-1. |
| [3] | ASTM Standard Recommended Practice for Constant-Amplitude Low-Cycle Fatigue Testing[R].ASTM designation : E606-80 |
| [4] | 蔡力勋 等.钛合金T42NG高温低周疲劳特性研究[R].成都:西南交通大学力学所研究报告,1997. |
| [5] | 蔡力勋 等.考虑温度效应的钛合金材料疲劳与循环特性研究[R].成都:西南交通大学力学所研究报告,2000. |
| [6] | 蔡力勋 等.18Cr2NiWA螺栓材料常温与高温低周疲劳特性研究[R].成都:西南交通大学力学所研究报告,1998. |
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