文献类型：期刊文献

英文题名：Uniaxial mean stress relaxation of 9-12% Cr steel at high temperature: Experiments and viscoplastic constitutive modeling

作者：Wu, De-Long[1];Xuan, Fu-Zhen[1];Guo, Su-Juan[1];Zhao, Peng[1]

机构：[1]E China Univ Sci & Technol, Key Lab Pressure Syst & Safety, MOE, Sch Mech & Power Engn, Shanghai 200237, Peoples R China

年份：2016

卷号：77

起止页码：156

外文期刊名：INTERNATIONAL JOURNAL OF PLASTICITY

收录：;EI(收录号：20165003110158);WOS:【SCI-EXPANDED(收录号:WOS:000370103200008)】；

基金：The authors are grateful for the supports provided by the National Natural Science Foundation of China (51325504, 11302079) and the Fundamental Research Funds for the Central Universities (13R21411900).

语种：英文

外文关键词：Mean stress relaxation; Constitutive behavior; Cyclic loading; Elastic-viscoplastic material

摘要：Symmetrical and asymmetrical strain cycling tests of X12CrMoWVNbN10-1-1 steel were conducted at 873 K. Significant rate dependence, mean stress relaxation and continuously cyclic softening behavior were observed during the fatigue process. In addition, a strain amplitude dependent competition between cyclic softening and mean stress relaxation was revealed. When the strain amplitudes were larger than the initial plastic point, the cyclic softening was dominated with a rapidly relaxed mean stress and a significantly altered hysteresis loop during the primary cycles. Whilst for the strain amplitudes being less than the initial plastic point, the continuously relaxed mean stress with unclearly altered hysteresis loops was observed during the whole lifetime. Accordingly, a new cyclic viscoplastic constitutive is proposed through the combination of a new nonlinear kinematic hardening rule and the Abdel-Karim Ohno model. The strain-amplitude dependent cyclic softening and mean stress relaxation behavior were finely reproduced by the proposed model, which was achieved by introducing a mean stress relaxation parameter as a function of the maximum plastic strain and the accumulated cyclic plastic strain. (C) 2015 Elsevier Ltd. All rights reserved.