Quasi-steady-state creep crack growth in a 3.5NiCrMoV steel

Abstract

Creep crack growth rate (ci) is usually characterized in terms of macroscopic load parameters, such as C*, C-t and C(t), through the constant load test. However, load parameters are continuously changing during the test, and so is a. Here, by conducting constant C-t and constant Delta tests, quasi-steady-state crack growth was obtained where a remained almost constant. Results indicate the a similar to[C-t](0.76) correlation, which differ from the a similar to[C-t](0.96) correlation of the constant load test. Discrepancies can be ascribed to the inclusion of the stage II data, which showed no correlation between a and C-t, in the constant load analysis. Finally, the crack growth rate was well predicted using the Monkmam-Grant analysis in creep crack growth.