Using the results of creep crack incubation tests on CrMoV steel for predicting long time creep rupture properties

The results of a series of creep crack incubation (CCI) tests have been used to examine the effectiveness of the LICON methodology for predicting long duration uniaxial rupture strength of a CrMoV steel at 550° C. The study has revealed that effective long time predictions can be made, but only with the availability of additional information including: an awareness of the short and long time rupture mechanisms and the associated multi-axial rupture criteria obeyed by the material, the results of uniaxial and multi-axial creep tests, and a knowledge of the steady state creep stress conditions existing in the testpieces (structures) forming part of the evaluation.In order to apply the creep damage enhancement approach to the low alloy creep resistant steel, it has been necessary to establish the steady-state creep stress state in the compact tension testpiece geometry used in the investigation. The new evidence is reviewed.