A low cycle fatigue model for low carbon manganese steel including the effect of dynamic strain aging

Abstract

Carbon-manganese steel A48 (French standards) is used in steam generator pipes of the nuclear power plant where it is subjected to the cyclic thermal load. The Dynamic Strain Aging (DSA) influences the mechanical behavior of the steel in low cycle fatigue (LCF) at favorable temperature and strain rate. The peak stress of A48 steel experiences hardening-softening-hardening (HSH) evolution at 200°C and 0.4%s -1 strain rate in fatigue loading. In this study, isotropic and kinematic hardening rules with DSA effect have been modified. The HSH evolution of cyclic stress associated with cumulative plastic deformation has also been estimated.

Physics-of-failure-based reliability and life prediction for critical components

“…Due to unexpected aging effects, mechanical properties of critical components often require safety consideration related to the mechanisms involved in aging, including multi-physics failure mechanisms, such as fatigue, creep, corrosion, and thermal aging. 1,2 As the next generation of major equipment, such as aircraft engine, steam turbine, and nuclear reactors, should work under extreme harsh conditions, continued improvements in reliability assessment and life prediction of critical components have been possible through the accurate modeling of multi-physics failure mechanisms and the introduction of advanced processing approaches. [3][4][5] Based on physics-of-failure (PoF) modeling, their performance degradation assessment, system reliability modeling, and life estimation should be conducted to maximize lifetime and optimize inspection and maintenance policy of critical components.…”