CrMoWV钢的应力松弛行为及其预测

以12Cr-1Mo-1W-0.25V耐热钢550,600℃的8760h松弛实验数据作为对象,研究短时间松弛数据准确而有效预测长时间松弛应力的方法。在采用松弛模型对长时间松弛应力进行直接拟合外推时,发现模型参数与所采用拟合数据的时间长度呈规律性的变化。提出考虑模型参数规律变化的时序参数法,以高精度预测长时间松弛应力。通过对比时序参数法与直接拟合外推法的预测结果,认为时序参数法在用短时间松弛数据预测长时间松弛应力上具有明显优势,预测结果的准确性较直接外推法高。

Stress Relaxation Behavior and Its Prediction of CrMoWV Steel

The stress relaxation data up to 8760h at 550℃ and 600℃of 12Cr-1Mo-1W-0.25V heat-resistant steel were used as the object to study the method of how to accurately and effectively predict long-term relaxation stress by using short-time relaxation data.When relaxation model is used to extrapolate the long-term relaxation stress directly,it is found that the parameters of the relaxation model depend on the length of the fitted data.The time-dependent parameter model,naming as timing parameter method,is proposed to predict the long-term relaxation stress with high accuracy.By comparison of the results of timing parameter method and direct extrapolation method,timing parameter method has obvious advantages in predicting long time relaxation stress with short time relaxation data,as the timing parameter method has a more accurate prediction than that of direct extrapolation method.