Effects of Creep Deformation Model of Gr. 91 Steel at 600°C on Creep Fracture Mechanics Parameters

Abstract

The present paper investigates the effect of creep deformation model of Gr. 91 Steel at 600 °C on creep fracture mechanics parameters. Three types of creep deformation model were considered, i.e. Garofalo’s model and RCC-MRx model for primary-secondary creep region, and modified omega model for primary-secondary-tertiary creep region. The parameters for each creep deformation model were characterized from experiment results. Reference Stress (RS) method was used to estimate creep fracture mechanics parameters, C(t)-integral and COD rate for each creep model. Furthermore, elastic-creep finite element (FE) analyses were carried out to verify the results of RS method. Finally, the effect of creep deformation model was investigated by comparing the results of C(t)-integral and COD rate.

Engineering C*‐integral and COD estimates for nonidealized circumferential through‐wall cracked pipes at elevated temperature

“…In the present study, these material constants are calibrated from the results of creep tensile tests of Gr. 91 steel at 600°C . t fp represents the end time of primary creep stage.…”

“…Comparisons of the idealized RCC‐MRx creep model results with experiment results [Colour figure can be viewed at wileyonlinelibrary.com]…”