Correlation of an expanded creep rupture data set of alloy HR6W to Larson-Miller, Wilshire, and hyperbolic sine creep life equations

HR6W alloy uniaxial creep life data from 600 °C to 900 °C were correlated to Larson-Miller, Wilshire, hyperbolic sine and simple power law creep life equations. Compared with previous correlations of a smaller HR6W data set, where temperatures ranged from 650 °C to 800 °C, goodness of fit of the Wilshire and hyperbolic sine equations was reduced; however, the calculated creep rupture strengths for 100,000 h life showed close agreement with published German Association of Technical Inspection Agencies values. All of the hyperbolic sine equations provided very good, numerically stable and similar correlations of the expanded data set with reasonably conservative predictions of long-term creep strength. The microstructural stability of HR6W is seen in the stable stress versus life behaviour across the entire range of the data and the fact that simple models correlated the data nearly as well as more complex or split region models.