Limiting State of 25Kh1M1FA Steel Under Long-Term Static Loading at Elevated Temperatures

Experimental results concerning application of the LM-hardness method for estimation of current state of 25Kh1M1FA steel and prediction of the residual resource of metal via the dependence of limiting values of homogeneity factors from effective stress level at working temperature are presented. The correlation between the levels of ultimate damageability and operating stresses, which could be considered linear in the first approximation, was established. A possibility of using the dependence of the material homogeneity coefficient on the level of effective stresses as a calibration dependence in selecting operating stresses and determining the residual service life of the material under continuous loading was shown. The reliability of the results obtained with the help of mathematical statistics methods based on physically justified laws of distribution was proved.