Formation mechanism and control of semi-macro-segregation in rail steel bloom
LI Hong-guang1, JI Cheng2, JIANG Dong-bin3, CHEN Tian-ming1, GUAN Rui2, CHEN Liang1
1. State Key Laboratory of Vanadium and Titanium Resource Comprehensive Utilization, Pangang Group Research Institute Co., Ltd., Panzhihua 617000, Sichuan, China; 2. School of Metallurgy, Northeastern University, Shenyang 110819, Liaoning, China; 3. School of Metallurgical andEcological Engineering, University of Science and Technology Beijing, Beijing 100083, China
Abstract:Continuous casting bloom of heavy rail steel is an important base metal for heavy rail, the solidification microstructure of semi-macroscopic segregation area in rail steel bloom was studied to optimize the homogeneity of rail steel bloom and improve internal quality at last. The effect of microstructure on the semi-macroscopic segregation area ratio was studied and revealed via electromagnetic stirring test in continuous casting, it was showed that the area of semi-macroscopic segregation increased with more highly-developed equiaxed grains. The technical methods were proposed to control semi-macroscopic segregation, and therefore, to optimize the homogeneity of rail steel blooms. The slim and long segregation bands observed in rail steels were mitigated, along with the Mn segregation degree reduced from 0.068 to 0.050 examed by in-site metal scanning detector.
李红光, 祭程, 姜东滨, 陈天明, 关锐, 陈亮. 重载钢轨钢连铸大方坯半宏观偏析形成机制与控制[J]. 钢铁, 2021, 56(6): 59-66.
LI Hong-guang, JI Cheng, JIANG Dong-bin, CHEN Tian-ming, GUAN Rui, CHEN Liang. Formation mechanism and control of semi-macro-segregation in rail steel bloom[J]. Iron and Steel, 2021, 56(6): 59-66.
[1] 张念, 张建峰, 于贵武,等. 大秦铁路重载钢轨踏面摩擦控制试验[J]. 中国铁路, 2011(12): 20.(ZHANG Nian, ZHANG Jian-feng, YU Gui-wu, et al. Test of tread friction control for heavy-haul rail of daqin railway [J]. China Railway, 2011(12): 20.) [2] 张银花, 李闯, 周清跃, 等. 我国重载铁路用过共析钢轨的试验研究[J]. 中国铁道科学, 2013, 34(6): 1. (ZHANG Yin-hua, LI Chuang, ZHOU Qing-yue, et al. Test study on hypereutectoid rail for heavy haul railway in China[J]. China Railway Science, 2013, 34(6): 1.) [3] Flemings M C. Our understanding of macrosegregation: Past and present[J]. ISIJ International, 2000, 40(9): 833. [4] Haida O, Kitaoka H, Habu Y, et al. Macro-and semi-macroscopic features of the centerline segregation in CC slabs and their effect on product quality[J]. Transactions of the Iron and Steel Institute of Japan, 1984, 24(11): 891. [5] GUAN Rui, JI Cheng, ZHU Miao-yong,et al. Numerical simulation of V-shaped segregation in continuous casting blooms based on a microsegregation model[J]. Metallurgical and Materials Transactions B, 2018, 49(5): 2571. [6] JI Y, LAN P,GENG H, et al. Behavior of spot segregation in continuously cast blooms and the resulting segregated band in oil pipe steels[J]. Steel Research International, 2018, 89(3): 1700331. [7] 王志涛,郭建兴,白利杰,等.钢板内部缺陷对性能的影响[J].宽厚板,2018,24(6):22.(WANG Zhi-tao, GUO Jian-xing, BAI Li-jie,et al. The effects of internal imperfections on steel plate properties[J]. Wide and Heavy Plate,2018,24(6):22.) [8] 周桂成,曹余良.电磁搅拌对钢板心部冲击韧性的影响[J].宽厚板,2018,24(6):37.(ZHOU Gui-cheng, CAO Yu-liang. Effect of electromagnetic stirring on impact toughness at steel plate center[J]. Wide and Heavy Plate, 2018,24(6):37.) [9] 张常青,崔健,宋书珍.渗碳齿轮辐板开裂失效分析[J].内燃机与配件,2017(19):11.(ZHANG Chang-qing, CUI Jian, SONG Shu-zhen. Study on the cracking failure of carburized gear disc [J]. Internal Combustion Engine and Parts, 2017(19):11.) [10] 廖庆亮,程亚杰,孙斌堂,等.二次带状组织对低合金非调质钢疲劳性能的影响[J].工程科学学报,2015,37(12):1581.(LIAO Qing-liang, CHENG Ya-jie, SUN Bin-tang, et al. Effect of secondary banded structure on the fatigue properties of non-quenched and tempered micro-alloyed steel [J]. Journal of University of Science and Technology Beijing,2015,37(12):1581.) [11] 李维彪, 王芳, 齐凤升, 等. 结晶器喂钢带连铸坯凝固过程的数学模拟[J]. 金属学报, 2007, 43(11): 1191.(LI Wei-biao, WANG Fang, QI Feng-sheng, et al. Mathematical model on steel strip-feeding of mold in continuous casting process [J]. Acta Metallurgical Sinica, 2007, 43(11): 1191.) [12] GUAN Rui, JI Cheng, ZHU Miao-yong. Modeling the effect of combined electromagnetic stirring modes on macrosegregation in continuous casting blooms[J]. Metallurgical and Materials Transactions B, 2020, 51(3): 1137. [13] JI Cheng, WU Chen-hui,ZHU Miao-yong. Thermo-mechanical behavior of the continuous casting bloom in the heavy reduction process[J]. JOM, 2016, 68(12): 3107. [13] Verhoeven, John D. A review of microsegregation induced banding phenomena in steels[J]. Journal of Materials Engineering and Performance, 2000, 9(3): 286. [14] 许志刚, 王新华, 黄福祥, 等. 管线钢连铸板坯的半宏观偏析和凝固组织[J]. 北京科技大学学报, 2014, 36(6): 751.(XU Zhi-gang, WANG Xin-hua, HUANG Fu-xiang, et al. Solidification structure and semi-macro segregation of pipeline steel continuous casting slabs [J]. Chinese Journal of Engineering, 2014, 36(6): 751.) [15] 兰鹏,铁占鹏,张伟,等. 连铸坯点状偏析缺陷研究进展[J]. 钢铁,2020,55(2):11.(LAN Peng, TIE Zhan-peng, ZHANG Wei, et al. Research progress on spot segregation defects in continuously cast semi-products [J]. Iron and Steel, 2020,55(2):11.) [16] Izutani M, Soejima T, Saito T, et al. Improvement of CC slab center segregarion[C]//4th International Conference Cotinuous Casting. Brussels: Verlag Stahleisen GmbH, 1988:115. [17] Pikkarainen T, Vuorenmaa V, Rentola I,et al. Effect of superheat on macrostructure and macro-segregation in continuous cast low-alloy steel slabs[C]//IOP Conference Series: Materials Science and Engineering. Bristol: IOP Publishing, 2016: 012064. [18] Oh K S, Chang Y W. Macrosegregation behavior in continuously cast high carbon steel blooms and billets at the final stage of solidification in combination stirring[J]. ISIJ International, 1995, 35(7):866. [19] Oh K S, Chang Y W. Macro and microscopic segregation behavior of center segregations in high carbon steel CC blooms during the final stage of solidification[J]. Process Technology, 1995, 13: 381. [20] Mizukami H, Komatsu M, Kitagawa T, et al. Effect of electromagnetic stirring at the final stage of solidification of continuously cast strand[J]. Tetsu to Hagane, 1984, 70(2):194.