@Article{icces.2022.08759,
AUTHOR = {M. Li, D.H. Li, Y. Rae, W. Sun},
TITLE = {Experimental And Numerical Modelling of Cyclic Softening and  Damage Behaviors for a Turbine Rotor Material at Elevated  Temperature},
JOURNAL = {The International Conference on Computational \& Experimental Engineering and Sciences},
VOLUME = {24},
YEAR = {2022},
NUMBER = {1},
PAGES = {1--2},
URL = {http://www.techscience.com/icces/v24n1/48979},
ISSN = {1933-2815},
ABSTRACT = {In order to better understand the physical process of deformation and cyclic softening a 12% Cr 
martensitic stainless steel FV566 has been cyclically tested at high temperature in strain control. 
Increase in temperature was found to increase the cyclic life, softening rate and viscous stress 
magnitude. An increase in the dwell time led to the acceleration of the material degradation. The 
microstructure changes and dominating deformation mechanisms were investigated by means of 
scanning electron microscopy, electron backscatter diffraction and transmission electron 
microscopy. The results have revealed a gradual sub-grain coarsening, transformation of lath 
structure into fine equiaxed sub-grains, and misorientation angle development in blocks and 
packets until material failure. Further, a unified viscoplastic constitutive model coupled with a 
physically-based damage variable, is proposed to capture the cyclic mechanical behavior and 
microstructural evolution of the material at elevated temperature. The mechanical strength can be 
reduced by the decrease in the dislocation density, the coarsening of the martensitic lath and the 
loss of the martensitic structure under cyclic loading. The proposed physically-based damage 
variable is driven by the evolutions of dislocation density and martensitic lath width. The good 
comparisons with test results mean that the proposed model can reasonably model the cyclic 
elastic-viscoplastic constitutive behavior of the material at high temperature.},
DOI = {10.32604/icces.2022.08759}
}