Abstract
The creep crack growth behavior of 1Cr-1 1/4Mo-1/4V steel was investigated at 565°C using center-notched plate specimens with proportional geometry in order to identify the most probable governing mechanical parameter of the phenomenon. It was found that even for this low ductile material the creep crack growth rate could successfully be correlated with modified J-integral J', regardless of the specimen size, while the stress intensity factor KI and the net section stress σnet gave poor correlation with the crack growth rate. This result was quite consistent with those obtained in previous papers using SUS 304 stainless steel which has a relatively high ductility. It was concluded that J' was the most probable mechanical parameter which governed the creep crack growth behavior.
