核电厂主管道材料低周疲劳寿命预测方法评价

Method of Life Prediction for Low Cycle Fatigue in PWR Primary Pipe Material

采用总应变控制方法,对压水堆核电厂主管道国产材料Z3CN20.09M进行了室温与350℃温度下的低周疲劳试验研究,获得了材料的疲劳寿命演化规律。采用Manson-Coffin方程、单拉估算模型、拉伸滞后能寿命模型和三参数幂函数公式对该材料的低周疲劳数据进行了拟合。通过寿命预测结果比较发现,除单拉估算模型外,其他几种模型对350℃高温下疲劳寿命的预测结果分散性明显高于室温疲劳。在众多模型之中,单拉估算模型拟合效果较差且预测寿命偏于非保守,而室温下拉伸滞后能法预测精度相对较高,350℃下则采用三参数幂函数法获得的预测效果更好。

An experimental study on the fatigue behavior of the NPP PWR primary pipe material Z3CN20.09M made in China is performed on a group test of low-cycle fatigue under room temperature and elevated temperature of 350℃. The Manson-Coffin equation, simple tensile prediction model, Ostergren model and three-parameter power function for low cycle fatigue（LCF） are investigated. The prediction results show that the life prediction capability in elevated temperature is weaker than that in room temperature for all models except the simple tensile prediction model. The simple tensile prediction model gives worst results, most of its predictions are on the non-conservative side, while the Ostergren model presents best predictions for room fatigue tests, and the three-parameter power function yields a good result in life prediction for elevated temperature fatigue tests.