METHOD OF PREDICTING REMINING LIFETIME OF METAL MATERIAL

摘要

The shapes of grains of a metal material are quantitatively measured, and the remaining lifetime of the material predicted on the basis of variations. The variations in said shapes are represented by a standard deviation of the distribution of angles which the direction of stress makes with the direction of the longitudinal axis of the maximum diameter of each of the grains. Alternatively, variations in the shapes are represented by a ratio of the maximum length of the longitudinal axis of each of the grains to the maximum width of an axis of each of the grains perpendicular to the longitudinal axis.