Development of creep constitutive equation for low alloy steel

High temperature creep tests of SA533B1 steel were performed under both constant load and constant stress conditions. Using the minimum creep strain rates as a function of the given stress and temperature conditions, simple power law type curve fittings were performed. Based on the results of curve fittings of constant stress data, creep constitutive law was developed. The constitutive law was then implemented in ABAQUS 5.8 and validated against Lower Head Failure (LHF) experiment executed in Sandia National Laboratories (SNL). The constitutive law was shown to be useful in predicting the lower head deformation behavior. Additional work, however, is needed to determine the correlation between the constant load data and constant stress data