Life Prediction of 316 Stainless Steel Under Creep‐fatigue Loading

Abstract

Life prediction for creep-fatigue loading conditions should be related to creep damage mechanisms. In order to examine the effect of the creep damage mode on rupture life under creep-fatigue loading, a "combined creep-fatigue loading test" was carried out on 316 stainless steel. In this method, creep loading and fatigue loading are repeated alternately. The fracture criteria under combined loading closely depend on the creep fracture modes of the static creep test. A new life prediction method which uses this new fracture criterion is proposed. The criteria are changed when the creep damage mode varies. In order to verify the adequacy of this method, fatigue tests with a tensile strain-hold wave form were carried out. It is clear that rupture life in such fatigue tests is dependent on the chosen fracture criteria.

Operation-Adaptive Damage Assessment of Steam Turbines Using a Nonlinear Creep-Fatigue Interaction Model

“…The linear cumulative damage rule is generally used to predict the lifetime of power plant components such as rotors, casings, and valves [26][27][28][29]; however, this approach is only applicable when the types of damage are independent of each other and do not overlap [19]. To overcome this limitation of linear damage models, this study implements a nonlinear continuum damage mechanics model to assess creep-fatigue damage of the HIP rotor [30].…”

Deformation and life assessment of high temperature materials under creep fatigue loading

“…Typical mechanisms of cavity growth have been identified in 1CrMoNiV steels during stress relaxation [27]. Grain boundaries may be cavitated in tensile hold time, but cavitation is usually not found in a balanced cycle containing hold time of equal duration.…”

“…which combines the Miner rule for fatigue damage and the life fraction rule for creep damage [3,7,13,14,23,27]. The damage summation over all cycles k including damage at hold times j =1 to 4 leads to a creep fatigue damage L. The structure of this relationship is relatively simple and therefore in practical use for life monitoring systems [28].…”