Long-term creep design data for forged 1Cr–1Mo–0.25V steel

Abstract

By analysing the shapes of short-term constant-stress creep curves, the θ methodology predicts the long-term creep and creep rupture values expected for oxidation-free conditions at 723 to 923 K, avoiding the underestimation of performance caused by testpiece oxidation during prolonged exposure in air at 823 K and above. The θ relationships also allow rationalization of multi-batch creep data sets for the 1Cr–1Mo–0.25V rotor steel, through new procedures which replace the empirical terms in traditional parametric methods with measurable properties, such as the 0.2% proof stress at the creep temperature.