Low Strain Creep of ex-service 0.5CrMoV Steel

Abstract

Helicoid spring creep testing technique with high strain sensitivity was applied on specimens of low-alloy steel after 197 thousands hours in service. The creep testing conditions were selected to be close to that of the service, that is 560 °C and 35MPa. The ex-service specimens creep much faster than the unused one and an anisotropy in creep properties was also observed. The method is capable to provide some additional information for the residual creep life assessment, but interpretation of the results is quite difficult. The large volume of the material needed for testing is also considerable disadvantage