Remaining life evaluation of 316LC steel based on a new creep-fatigue damage rule

Creep-fatigue remaining life of 316LC steel subjected to PP-type testing and CP-type testing is evaluated by use of two procedures that the authors proposed in the previous work for Mod.9Cr-1Mo steel. A new creep-fatigue damage rules determined by the authors for 316LC steels are used, where crack initiation life cannot be neglected in CP-type straining or in PP type straining. The results show that both proposed procedures yield more accurate estimations of remaining life, material damage and applied inelastic strain range for 316LC steel than for Mod.9Cr-1Mo steel. Among the two procedures, procedure I yields superior prediction accuracy over procedure 2, where the former requires measurement of surface crack length at a given total number of cycles, whereas the latter requires measurement of surface crack growth rate. Especially satisfactory results are obtained when procedure I is adopted and the measured surface crack length is 300,mum or longer. That is, the ratio of the predicted value of remaining life to the actual value is below 1.1 and the corresponding ratios for material damage and applied inelastic strain range are from 0.9 to 1.3.