Influence of Nb on microstructure and property of low-carbon Mn-series air-cooled bainitic steel
The effect of Nb on the microstructure evolution of low-carbon Mn-series air cooled bainitic steels has been studied by using thermomechanical simulation machine, SEM, and TEM observation. The results show that the amount of ferrites is relatively higher in the steel without Nb than that of Nb-bearing steel under same deformation conditions, and the ferrites in Nb-bearing steel are more finer. The mechanical properties of the Nb-bearing steel are higher than those of the steel without Nb at the same finishing rolling temperature (FRT), and the toughness of the Nb-bearing steel is about 100 J higher than that of the steel without Nb at the finishing rolling temperature 750 °C. The toughness of Nb microalloyed steel will be improved more effectively than that of the steel without Nb with the decrease of FRT.
Key wordsMn-series bainitic steel grain boundary allotriomorphic ferrite finishing rolling temperature Nb micro-alloyed steel toughness
Unable to display preview. Download preview PDF.
- WANG Jian-ping, YANG Zhi-gang, BAI Bing-zhe, et al. Influence of Austenite Deformation on the Microstructure Strength and Toughness of the Grain Boundary Allotriomorphic Ferrite/Granular Bainite (FGBA/GB) Duplex Steel [J]. Acta Metallurgica Sinica, 2004, 14 (3): 263 (in Chinese).Google Scholar
- CAO Jian-chun, LIU Qing-you, YONG Qi-long, et al. Effect of Niobium on Microstructure and Strengthening Mechanism of HSLA Steel [J]. Journal of Materials and Metallurgy, 2006, 41(8): 60.Google Scholar
- HUANG Hai-bing, BAI Bing-zhe, FENG Yong, et al. Study on Deformation Induced Ferrite Transformation of the Grain Boundary Allotriomorphic Ferrite/Granular Bainite (FGBA/Bg) and Nb-Ti Microalloyed Duplex Steel [J]. Heat Treatment of Metals, 2006, S1: 124 (in Chinese).Google Scholar
- CHEN Guo-an, YANG Wang-yue, GUO Shou-zhen, et al. Characteristics of Dynamic Transformation During Deformation of Undercooled Austenite in Nb-Microalloyed Steel [J]. Transactions of Materials and Heat Treatment, 2006, 27(6): 89 (in Chinese).Google Scholar
- CHEN Guo-an, YANG Wang-yue, GUO Shou-zhen, et al. Carbonitride Precipitates During Deformation of Undercooled Austenite in Nb-Microalloyed Steel [J]. Journal of University of Science and Technology Beijing, 2005, 27(3): 302 (in Chinese).Google Scholar