|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Materials for High Temperature Applications: Next Generation Superalloys and Beyond
||F-59: Physics-based Creep Model of Ni-based Alloy Welds in High Temperature and Pressure Applications using Crystal Plasticity
||Wen Jiang, Pritam Chakraborty, Thomas M Lillo
|On-Site Speaker (Planned)
The long-term mechanical behavior of thick section welds of Ni-based alloys in high temperature and pressure applications often defines the operational limits and system inspection requirements. In the present work, a dislocation-density based crystal plasticity model is developed to simulate the time-dependent deformation behavior of 740H welds at ultra supercritical conditions. At the operating conditions of interest, dislocation climb and glide has been identified as the dominant mechanisms and is incorporated in the model. The effect of γ’ particles on the creep-rate is modeled by considering their resistance to dislocation motion and the bypassing of the particles by dislocation climb and Orowan looping, as well as the antiphase boundary (APB) shearing of the particles by super-dislocations. Subsequently, several single and polycrystalline simulations are performed to verify the workability of the model and compare the secondary creep rates with available experimental data.