文献类型：期刊文献

英文题名：Enhancing yield strength-ductility synergy of carbide-free bainitic steel through ausforming combined with low-temperature baking

作者：Xu, Ning[1];Zhang, Xi[1];Jiao, Haitao[1];Jiang, Yuqaing[1];Wu, Dong[1];Wang, Jinliang[2];Xi, Xiaohui[2];Huang, Zhichao[1]

机构：[1]East China Jiaotong Univ, Sch Mat Sci & Engn, Nanchang 330013, Peoples R China;[2]Guangdong Ocean Univ, Sch Mech Engn, Zhanjiang 524088, Peoples R China

年份：2026

卷号：974

外文期刊名：MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

收录：SCI-EXPANDED(收录号：WOS:001828545100001)、、EI(收录号：20262921131995)、Scopus(收录号：2-s2.0-105044928361)、WOS

基金：This work was supported by the National Natural Science Foundation of China (Grant No: 52401141, Grant No: 52565035) .

语种：英文

外文关键词：Low-carbon CFB steel; Ausforming; Low-temperature baking; Bainitic ferrite; Tempering martensite; Retained austenite; Strength-ductility

外文摘要：Traditionally low-carbon carbide-free bainitic (CFB) steel are limited by a lower retained austenite (RA) fraction and higher fresh martensite (FM) fraction, making it difficult to achieve an excellent strength-ductility synergy, and thereby restricting their industrial application. To solve this issue, this paper reveals the effects of ausforming combined with low-temperature baking on microstructural evolution and mechanical properties of lowcarbon CFB steel. The results show that ausforming increases the BF and RA contents. Specifically, the bainitic ferrite (BF) fraction increases from 59.2% of the pure bainitic transformation (PBT) sample to 67.4% of the ausforming bainitic transformation with 20% deformation (ABT20) sample, while the RA fraction increases from 10.6% of the PBT sample to 15.5% of the ausforming bainitic transformation with 20% deformation (ABT20 sample) and 15.0% of the combined with tempering at 190 degrees C for 1800 s (ABT20-T190) sample. Subsequent lowtemperature baking further enhances the stability of retained austenite, increasing its carbon content from 1.10 wt% of the PBT sample and 1.26 wt% of the ABT20 sample to 1.32 wt% of ABT20-T190 sample. Accordingly, the yield strength (YS) improves from 788 MPa of the PBT sample to 886 MPa of the ABT20 sample and 992 MPa of the ABT20-T190 sample. Moreover, the ausforming combined with low-temperature baking also enhances ductility and formability, the total elongation (TEL) increases from 13.7% of the PBT sample and 16.8% of the ABT20 sample to 20.1% of the ABT20-T190 sample, and in the hole expansion ratio (HER) increases from 20.5% of the PBT sample and 32.4% of the ABT20 sample to 35.1% of the ABT20-T190 sample. Overall, the ausforming combined with low-temperature baking effectively optimizes the microstructures, thus improving strength-ductility synergy of low carbon CFB steel.