Mean Stress Relaxation Process of 9-12% Cr Steel at High Temperature:Internal Stresses and Dislocation Patterns
Mean stress relaxation of advanced 9-12% chromium ferrite steel at elevated temperature were experimentally investigated and simulated reasonably by a new viscoplastic constitutive model D.L.Wu,.Z.Xuan, S.J.Guo and P.Zhao, Int.J.Plasticity, 77 (2016) 156.In order to reveal the physical mechanisms of mean stress relaxation process, a study of cyclic deformation response and associated microstructural evolution in 9-12% Cr steel was presented in this paper.Results indicated that two main domains were observed depending on the strain amplitude, in which the softening and relaxation mechanisms were different.Special attention was paid to the dependence of cyclic detormation mechanism on the variations of internal stress.It was demonstrated that the contribution of effective stress to the cyclic softening response was increasingly higher in the low strain amplitude (L-SA) domain.In contrast,back stress becomes less important to the cyclic deformation response for thc L-SA domain.In particular, the role of value of mean internal stress was highlighted.Di fferent from the results of ratcheting process, in mean stress rclaxation case, only the mean back stress (not the back stress amplitude) affected the relaxation rate.
Mean stress relaxation internal stresses dislocation patterns cyclic softening.9-12 Cr steel
Peng Zhao De-Long Wu Fu-Zhen Xuan
Key Laboratory of Pressure System and Safety, MOE;School of Mechanical and Power Engineering;East Ch Key Laboratory of Pressure System and Safety, MOE;School of Mechanical and Power Engineering;East Ch Key Laboratory of Pressure System and Safety, MOE;School of Mechanical and Power Engineering;East Ch
国际会议
长沙
英文
247-251
2016-10-16（万方平台首次上网日期，不代表论文的发表时间）