文献类型：期刊文献

英文题名：Sequential γ- ε- α′ transformation preserves high elongation in an ultrafine-grained high Mn steel

作者：Dong, Guangqi[1];Wang, Lingyu[1];Wang, Jinliang[2];Yuan, Jiahua[1];Huang, Minghao[3];Wang, Chenchong[1];Li, Yizhuang[1];Xu, Wei[1]

机构：[1]Northeastern Univ, State Key Lab Rolling & Automat, Shenyang 110819, Peoples R China;[2]Guangdong Ocean Univ, Sch Mech Engn, Zhanjiang 524088, Peoples R China;[3]Hangzhou City Univ, Adv Mat Addit Mfg Innovat Res Ctr, Hangzhou 310015, Peoples R China

年份：2025

卷号：257

外文期刊名：SCRIPTA MATERIALIA

收录：SCI-EXPANDED(收录号：WOS:001366776800001)、、EI(收录号：20244817418134)、Scopus(收录号：2-s2.0-85209730989)、WOS

基金：This work was supported by the Natural Science Foundation of China (No. 52201112, 52101133, and 52311530082) , and the Applied Basic Research Program of Liaoning Province (No. 2023JH2/101300147) . We thank Xiuxing Peng for the help on nanoindentation experiments.

语种：英文

外文关键词：Sequential gamma-epsilon-alpha ' transformation; Ultra-fine grain; Uniform elongation; Variant selection; Transformation kinetics

外文摘要：While grain refinement is a prominent way to improve the yield strength of metastable austenitic steels, it usually leads to a reduction in the uniform elongation as gamma-alpha ' transformation tends to be suppressed. In the current study, it is found that the sequential gamma-epsilon-alpha ' transformation helps an ultrafine-grained high Mn austenitic steel maintain high uniform elongation while having more than doubled yield strength compared to the coarse-grained counterpart. Although the grain refinement is unfavorable for the gamma-epsilon transformation due to epsilon variant selection within the refined gamma grains, the epsilon-alpha ' transformation is not affected as multiple alpha ' variants can form within one epsilon grain. The combination of a higher alpha ' transformation rate and delayed transformation kinetics enables continued strain hardening, leading to high uniform elongation.