文献类型：期刊文献

英文题名：Interaction of cyclic softening and stress relaxation of 9-12% Cr steel under strain-controlled fatigue-creep condition: Experimental and modeling

作者：Zhang, Shang-Lin[1];Xuan, Fu-Zhen[1]

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

年份：2017

卷号：98

起止页码：45

外文期刊名：INTERNATIONAL JOURNAL OF PLASTICITY

收录：;EI(收录号：20172803902186);WOS:【SCI-EXPANDED(收录号:WOS:000412614000003)】；

基金：The authors are grateful for the supports provided by the National Natural Science Foundation of China (51325504, 51475167) and the Program of Shanghai Subject Chief Scientist (14XD1401300).

语种：英文

外文关键词：Fatigue-creep interaction; Cyclic stress relaxation; Unified viscoplastic model; 9-12% Cr steel

摘要：Strain controlled fatigue of P92 steel with various strain hold dwells introduced at the peak loading point were conducted at 625 degrees C. Two features which depend on the cycle and strain range level were observed under the fatigue-creep condition for the viscous and cyclic softening material. The first one is the accelerated cyclic softening response which is ascribed to the accumulated inelastic strain transformation from the creep mechanism during the strain dwell period and becomes more significant with the decrease of strain ranges. The second one is the decelerated stress relaxation behavior which is caused by the reduced viscous stress related to the continuous cyclic softening and fades with the decrease of cyclic strain ranges. Accordingly, a new unified viscoplastic constitutive model within the framework of Chaboche model was developed by improving the nonlinear isotropic hardening rule and the kinematic hardening rule with a cyclic softening parameter. As a result, the accelerated cyclic softening and decelerated stress relaxation response of fatigue-creep interaction was finely reproduced by the proposed model. (C) 2017 Elsevier Ltd. All rights reserved.