Fatigue-creep life prediction of 2 1/4Cr-1Mo steel by inelastic analysis

This paper covers the second part of the Benchmark Project by the Subcommittee on the Inelastic Analysis and Life Prediction of High Temperature Materials, JSMS, concerning the life prediction methods under fatigue-creep interaction by taking into account the plasticity-creep interaction described by the constitutive models treated in the first part. By specifying a normalized and tempered 2 1/4Cr-1Mo steel at 600degC, uniaxial fatigue-creep tests under six patterns of strain waves are performed. Adopting eight types of life estimation methods, two kinds of life prediction procedures are examined: one is a normal way based on an experimentally obtained stress-strain hysteresis loop; and the other is a way of employing the calculated stress-strain hysteresis loop by use of ten types of constitutive models. Predicted lives of the material are compared with observed failure lives, and discussions on the evaluation of the methods are included