Creep crack growth in X20CrMoV 12 1 steel and its weld joint

Abstract

A combined experimental and computational study, is carried out on creep crack growth in X20CrMoV 12 1 steel and its weld joint. Crack growth rests are conducted on compact specimens at 545 degreesC. For weld specimens, the crack propagates in the heat-affected zone parallel to the fusion line. It is found that C*(t) correlates crack growth rates satisfactorily under the loads used in the test not only for base metal specimens but also for weld specimens. An elastic-plastic-steady-state creep analysis of crack growth is performed using a finite element code. Calculated load point displacement rates agree with experimental measurements during steady-state crack growth. The creep zone is asymmetric, and it becomes more so in weld specimens as the crack propagates. Yet the mode II effect appears to be insignificant.