文献类型：期刊文献

英文题名：Dynamic strain ageing of austenitic Ni-based alloy during cyclic loading at 350 °C: Mechanism and its evolution

作者：Zhao, Peng[1];Wang, Ning[1];Zhang, Pan[1];Yu, Hao[1];Gong, Jian-Guo[1];Xuan, Fu-Zhen[1]

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

年份：2024

卷号：33

起止页码：4713

外文期刊名：JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T

收录：;EI(收录号：20240267455);WOS:【SCI-EXPANDED(收录号:WOS:001339718600001)】；

基金：This work was supported by the National Natural Science Foundation of China (Grant No.: 52275150 and 52275148) and the Natural Science Foundation of Shanghai (Grant No.: 21ZR1418200) .

语种：英文

外文关键词：Dynamic strain ageing; Low cycle fatigue; Dislocation structure; Austenitic Ni-Based alloy

摘要：Dynamic strain ageing (DSA) in an austenitic Ni-based alloy was investigated by symmetric/asymmetric low cycle fatigue tests with different strain amplitudes at 350 degrees C. A quantitative analysis of DSA activity was provided in terms of the characteristic parameters (DSA transient and serration length), and associated microstructural features were explored. Particular attention was paid to the comparison in the DSA domain between Ni- and Febased austenite with different strain ratios. Results showed that DSA existed throughout life and led to the continuous cyclic hardening in austenitic Ni-based alloy. The DSA activity first decreased and remained almost constant under symmetric loadings. A gradual increase in DSA activity was observed for the asymmetric loadings before the final failure. In addition, a physical model was presented to explore the DSA mechanisms of austenitic Ni-based alloys in different temperature ranges. Specifically, at 350 degrees C, DSA is caused by C diffusion in austenite, while at higher temperatures, it may be caused by Cr diffusion. Moreover, for a given mechanism, the DSA occurred at a higher temperature range in Ni-based alloy than in Fe-based alloy.