文献类型：期刊文献

英文题名：New Insights on the Effect of Grain Size on Martensitic Transformation in Metastable Austenite Steel

作者：Wang, Jinliang[1,2,3];Liu, Xing[1,2,3];Ai, Zhengrong[4];Dong, Guangqi[5];Huang, Minghao[6];Shen, Chunguang[7];Zhang, Zhen[7];Xi, Xiaohui[1,2,3]

机构：[1]Guangdong Ocean Univ, Sch Mech Engn, Zhanjiang Key Lab Corros & Protect Ocean Engn Equi, Zhanjiang 524000, Peoples R China;[2]Guangdong Engn Technol Res Ctr Ocean Equipment & M, Zhanjiang 524088, Peoples R China;[3]Guangdong Ocean Univ, Guangdong Prov Key Lab Intelligent Equipment South, Zhanjiang 524088, Peoples R China;[4]Northeastern Univ, Sch Mat Sci & Engn, Shenyang 110819, Peoples R China;[5]Northeastern Univ, State Key Lab Rolling & Automat, Shenyang 110819, Peoples R China;[6]Hangzhou City Univ, Hangzhou 310015, Peoples R China;[7]Hebei Univ Technol, Tianjin 300130, Peoples R China

年份：2025

外文期刊名：METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE

收录：SCI-EXPANDED(收录号：WOS:001506929800001)、、EI(收录号：20252418604629)、Scopus(收录号：2-s2.0-105007938243)、WOS

基金：The research was financially supported by the support of National Natural Science Foundation of China (Grant Nos. 52401141, 52101133 and 52201112), the support of Guangdong Basic and Applied Basic Research Foundation (Grant No: 2024A1515010726), the support of Innovation Team Project for Ordinary Universities in Guangdong Province (Grant Number 2024KCXTD041), the support of Natural Science Foundation of Hebei Province (Grant No. E2024202070), and the support from the Zhejiang Provincial Natural Science Foundation of China (Grant No. LQ24E040003).

语种：英文

外文摘要：Understanding the thermal stability of austenite is critical for designing high-performance steels. Grain size is a key factor controlling thermal stability, but the underlying mechanisms remain partially unclear. For instance, the grain boundary nucleation theory fails to explain why small-grained austenite exhibits higher thermal stability. While strong martensite variant selection in small-grained austenite has been proposed as a contributing factor, the mechanistic role of grain size in this selection process remains unresolved. In this study, quasi-in-situ ECCI and EBSD characterization techniques were employed to investigate these mechanisms. The results demonstrate that grain size influences martensitic transformation nucleation behavior, thereby affecting austenite thermal stability. Compared to fine-grained austenite, coarse-grained austenite more readily forms nucleation sites (e.g., faulted bands) during cooling. Furthermore, the diversity of martensite packet variants is determined by the variant types of faulted bands. The variant types of faulted bands are themselves governed by austenite grain size. As grain size decreases, faulted bands transition from multiple variants to a single variant. Consequently, martensite in small-grained austenite forms via a single-variant mode, enhancing austenite stability. This study is the first to elucidate the grain size effect on austenite thermal stability through the lens of martensitic transformation nucleation and crystallography.