文献类型：期刊文献

英文题名：Ratcheting-fatigue behavior and fracture mechanism of 316H ASS under cyclic random loading block

作者：Zhou, Wei-Tong[1];Zhou, Guo-Yan[1];Si, Jun[2];Xiong, Xue-Yao[1];Tu, Shan-Tung[1]

机构：[1]East China Univ Sci & Technol, Sch Mech & Power Engn, Key Lab Pressure Syst & Safety, MOE, Shanghai 200237, Peoples R China;[2]Shanghai Inst Special Equipment Inspect & Tech Res, Shanghai 200062, Peoples R China

年份：2025

卷号：191

外文期刊名：INTERNATIONAL JOURNAL OF FATIGUE

收录：;EI(收录号：20244617350040);WOS:【SCI-EXPANDED(收录号:WOS:001355871200001)】；

基金：This work was supported financially by the National Natural Science Foundation of China (Grant No. 52075173) .

语种：英文

外文关键词：Synergistic damage; Random loading block; Normalized strain amplitude; Stacking fault; alpha'-martensite

摘要：In this study, a set of programmed random factors with non-zero mean were designed. Then various stress levels (15, 18 and 22 KN) were multiple superimposed to factors to form one random loading block (RLB), the blocks were repeated to failure to investigate the synergistic damage of 316H ASS under low-cycle fatigue (LCF), highcycle fatigue (HCF) and ratcheting effect. The lifetime of cyclic RLB tests decreased with the increase of blockmean stresses sigma Block m (208,255 and 311.5 MPa). The normalized strain amplitudes indicate that when the sigma Block amplitude below the yield strength (208 and 255 MPa), a stable ratchet accumulation phase allows the specimens to exhibit cyclic hardening behavior. When sigma Block m (311.5 MPa) exceeds the yield strength, the ratcheting strain increases significantly and the specimens exhibit cyclic softening behavior. Especially, the transgranular cleavage fracture, quasi-cleavage fracture and intergranular secondary cracks were identified when the failure of cyclic RLB tests were induced by LCF, HCF and ratcheting. With the increase of sigma Blockm amplitude, the decrease of LAGB proportion and the increase of dislocation density further reduce the fatigue resistance. In addition to dislocation motion, the alpha'-martensite phase transformation induced by ratcheting-fatigue has been further demonstrated as a mechanism for coordinated deformation. The percentage of stresses (within one block) that exceeds the diverge critical stress (375.6 MPa) of stacking faults (SFs) determines the alpha'-martensite nucleation mechanism.