In-situ and ex-situ microstructure studies and dislocation-based modelling for primary creep regeneration response of 316H stainless steel

The emergence of renewable energy sources with their variable and unpredictable nature, in addition to the variation need for weekdays vs. weekends, demands an ever flexible operation thermal power plants. Such a feature has therefore altered typical steady creep loading high-temperature components plants stress-varying or cyclic conditions. introduced load transients have been found affect strain hardening memory creeping alloys might lead multiple primary regeneration (PCR). Therefore, accumulation can considerably increase under such Consideration PCR phenomenon is beyond capability conventional constitutive models which are based on strain- time-hardening assumptions. present study conducted in-situ ex-situ experiments 316H stainless steel. Various microstructural examination techniques, as synchrotron high X-ray neutron diffraction, backscattered transmission electron microscopy, employed characterising evolution dislocation structure internal lattice strain/stress state alloy during formation/annihilation pileups bowing/unbowing dislocation-lines were identified responsible mechanisms PCR. A dislocation-based model was then formulated could well represent measured mechanical response steel at 650°C.