METHOD OF EVALUATING CREEP LIFE EXPECTANCY OR LIFE SPAN

摘要

A method of accurately evaluating the life expectancy or the life span of a creep-damaged device member, especially its fine-grained part. The life expectancy or the life span is represented by the time until the creep-damaged device member creep-ruptures. The number of linked voids present over a half or more of each length of two or more grain boundaries in areas of up to 1 mm2 of the surface of the device member is determined. The ratio of the number of linked voids to the area of 1 mm2 is used as an L parameter, and the life expectancy or the life span of the device member is evaluated on the basis of the L parameter.