文献类型：期刊文献

英文题名：Multi-stage dwell fatigue crack growth behaviors in a nickel-based superalloy at elevated temperature

作者：Wang, Ji[1];Wang, Run-Zi[1];Zhang, Xian-Cheng[1];Ye, You-Jun[2];Cui, Yan[3,4];Miura, Hideo[5];Tu, Shan-Tung[1]

机构：[1]East China Univ Sci & Technol, Sch Mech & Power Engn, Key Lab Pressure Syst & Safety, Minist Educ, Meilong Rd 130, Shanghai 200237, Peoples R China;[2]Jiangsu Prov Special Equipment Safety Supervis In, Nanjing 210009, Peoples R China;[3]East China Univ Sci & Technol, Sch Chem & Mol Engn, Key Lab Adv Mat, Shanghai 200237, Peoples R China;[4]East China Univ Sci & Technol, Sch Chem & Mol Engn, Feringa Nobel Prize Scientist Joint Res Ctr, Shanghai 200237, Peoples R China;[5]Tohoku Univ, Grad Sch Engn, Fracture & Reliabil Res Inst, Sendai, Miyagi 9808579, Japan

年份：2021

卷号：253

外文期刊名：ENGINEERING FRACTURE MECHANICS

收录：;EI(收录号：20212810625591);WOS:【SCI-EXPANDED(收录号:WOS:000684789800001)】；

基金：This work was supported financially by the National Key Research and Development Program of China (2018YFC1902404), the National Natural Science Foundation of China (Nos. 52005185, 51725503 and 52005184), Shanghai Sailing Program (20YF1409600), China Postdoctoral Science Foundation (2020M681200) and 111 Project. Wang RZ and Miura H also gratefully acknowledge the support of the Postdoctoral Fellowships for Research in Japan (FY2020 P20350) by the Japan Society for the Promotion of Science (JSPS).

语种：英文

外文关键词：Nickel-based superalloy; Dwell fatigue; Crack growth; Replica technique; EBSD analysis

摘要：A series of continuous and interrupted cyclic tests in Inconel 718 with the dwell times ranging from 0 s to 10,800 s at 650 degrees C were carried out in order to study the multi-stage dwell fatigue crack growth (DFCG) behavior. Replica technique was used to measure the intermittent DFCG rates from short to long periods and to retrospect specific damage mechanisms based on microstructural characterizations. From the macroscopic viewpoint, the DFCG curves were classified into short, moderate and long dwell conditions according to the tendencies in DFCG rates. Correspondingly, the dwell fatigue life distribution was divided into three periods, which exhibit different sensitivities in the length of dwell time on dwell fatigue life. From the microscopic viewpoint, the high-scattered points reflected in the DFCG curves were elaborately discussed with the combinations of EBSD mapping and high-resolution TEM analysis. sigma 3 twin boundaries (sigma 3 TBs) were regarded as the barriers to resist the DFCG due to their special performances. In addition, with the increase of dwell times, the main crack morphologies changed from transgranular to intergranular mode. Simultaneously, local crack growth modes at high-scattered points changed from across to along the sigma 3 TBs with extreme low DFCG rates. Also, high-angle crack deflection was another factor that was responsible for the decrease of the DFCG rates.