EVALUATING METHOD FOR CREEP LIFE EXPECTANCY OF HIGH TEMPERATURE EQUIPMENT

摘要

PURPOSE:To evaluate life expectancy with high accuracy by estimating a creep chart and a creep rupture chart before use from the hardness of the high- temperature equipment before use. CONSTITUTION:A creep curve is determined based upon data on a received material test result document. The obtained creep curve is used to calculate variation in creep stress with time together with the temperature of a rotor. Then a hardness variation ratio chart is determined based upon the data of the received material test result document. The ratio of hardness up to a current point at a position where the life expectancy is to be found is estimated from said chart. Then the hardness is measured and the hardness before use is calculated from the result of the estimated value. The creep and creep rupture chart before use are estimated based upon the obtained hardness before use and chemical composition entered into the material test result document. Creep damage is calculated from them. Then the use time up to now is subtracted from the time when the creep damage reaches 1. The obtained result is the life expectancy.