The Remaining Life Evaluation Based on A New Creep-Fatigue Damage Rule for Mod.9Cr-1Mo Steel
Tokimasa Katsuyuki; Miyahara Mitsuo
Abstract:The idea and procedures are presented for evaluating the remaining life based on a new creep fatigue damage rule. The proposed method needs only information about crack length at a given number of cycles or crack length change during a given cycles interval and Fij, the ratio of the partitioned inelastic strain range to the total inelastic strain range. It is shown that the material damage and the applied inelastic strain range as well as the remaining life of IJ tested Mod.9Cr 1Mo steel can be evaluated when the difference between the measured crack length and the hypothetical initial crack length or the measured crack length change is greater than 30mm, and that the respective accuracy in predicting each of the remaining life, the applied inelastic strain range and the material damage is within about factor of 3 - 4, 2.5 - 2.8 and 1.5 - 3. Key Words:creep-fatigue, material damage, small crack, remaining life prediction, Mod.9Cr-1Mo