Pressurized Thermal Shock Experiments with Thick Vessels

Abstract

A 148-mm-thick pressure vessel containing a long axial flaw was subjected to a combined loading of internal pressure and thermal shock. The experiment was performed to investigate the effects of loading sequence on initiation of brittle fracture and the behavior of a crack propagating into ductile regions. Two crack initiation and arrest episodes were generated, in addition to several phases of warm prestressing. Warm prestressing was shown to be effective in inhibiting initiation of cleavage fracture. A crack arrest was observed 88 K above the reference nil-ductility transition temperature (RTNDT) with a stress-intensity factor of 299 MPa √m.