High temperature crack growth behavior in a Cr-Mo steel weldment

Creep deformation and creep crack growth experiments have been conducted on Cr-Mo steel weldment in order to provide information on residual life prediction of structural component weldment containing cracks. The stress exponent of creep deformation equation for the base metal and weldment at 823K were found to be 10.2 and 7.3, respectively. The creep rate of the weldment was much lower than that of the base metal. The creep crack growth rate of the weldment was almost twice as high as that of base metal under a fixed value of C. This may indicate that the weldment is stronger than the base metal in view of creep deformation and is more brittle during creep crack growth due to the intrinsic bainite microstructure.