工程科学学报.第42卷.第7期：862-868.2020年7月 Chinese Journal of Engineering,Vol.42,No.7:862-868,July 2020 https://doi.org/10.13374/j.issn2095-9389.2020.03.16.003;http://cje.ustb.edu.cn 连铸坯脱氢退火数值模拟 姜东滨，智建国)，宋海，高勇2)，张立峰)⑧ 1)北京科技大学冶金与生态工程学院，北京1000832)包头钢铁有限责任公司.包头0140003)燕山大学亚稳材料制备技术与科学国家 重点实验室.秦皇岛066044 ☒通信作者，E-mail:zhanglifeng@ysu.edu.cn 摘要采用数学模拟方法研究钢轨钢连铸坯脱氢退火行为，分析不同退火温度、退火时间条件下连铸坯脱氢效果，优化了 脱氢退火工艺.在脱氢退火过程中，连铸坯角部和边部的氢含量快速降低，而连铸坯中心氢含量在加热段后期开始降低：随 着退火温度的升高，连铸坯中心脱氢的起始点明显提前，最大脱氢速率显著增加.随着均热段时间逐渐延长，连铸坯中心氢 含量明显降低，但脱氢速率的增加幅度逐渐减小.通过优化脱氢退火工艺参数，连铸坯中心氢的质量分数能够降低至 0.6×106,脱氢效果显著 关键词大方坯；脱氢：退火温度；退火时间：数值模拟 分类号TF777.2 Numerical simulation of dehydrogenation annealing in bloom JIANG Dong-bin,ZHI Jian-guo,SONG Ha),GAO Yong,ZHANG Li-feng 1)School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China 2)Baotou Iron and Steel Co.Ltd.,Baotou 014000,China 3)State Key Lab of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao066044,China Corresponding author,E-mail:zhanglifeng @ysu.edu.cn ABSTRACT Due to moisture in the ore,auxiliary material,and ladle refractory material,the hydrogen element is easily enriched in molten steel.In the metallurgy process,some hydrogen atoms form bubbles and are removed by gravity,whearas others solidify in the strand and remain in the produced steel.When the hydrogen content reaches a certain critical value,the enriched hydrogen atoms congregate to produce a white spot,which greatly reduces the strength and toughness of the steel product,and leads to brittle fracture during its service period.At present,the RH(Ruhrstahl-Heraeus)and VD(vacuum degasser)refining processes are commonly applied in steel plants,which can reduce the hydrogen content to less than 2x.With the demand for high quality steel,the hydrogen content must be further decreased,so hydrogen diffusion in solid steel during the annealing process is gradually attracting increasing attention.In this study,a two-dimensional model was built to investigate the characteristic of dehydrogenation in the bloom annealing process of rail steel.Moreover,the effect of annealing temperature and annealing time on hydrogen diffusion were analyzed,and the annealing parameters were optimized.During the dehydrogenation annealing process,the hydrogen content at the corners and edges of the bloom are found to decrease rapidly,while that in the center of the strand begin to decrease in the later heating stage.As the annealing temperature increases,the starting point of dehydrogenation in the bloom center moves ahead and the maximum dehydrogenation rate increases significantly.With the extension of the soaking period,the central hydrogen content of bloom decreases significantly,but the increase rate of the dehydrogenation gradually decreases.By optimizing the bloom annealing parameters,the hydrogen content in the 收稿日期：2020-03-16 基金项目：国家自然科学基金资助项目(U186026.51725402.51904024):中央高校基本科研业务费资助项目(FRF.TP18-098A1):中国国家 重点研发计划专项资助项目(2017YFB0304001):博士后科学基金面上资助项目(2018M641194)连铸坯脱氢退火数值模拟 姜东滨1)，智建国2)，宋    海2)，高    勇2)，张立峰3) 苣 1) 北京科技大学冶金与生态工程学院，北京 100083    2) 包头钢铁有限责任公司，包头 014000    3) 燕山大学亚稳材料制备技术与科学国家 重点实验室，秦皇岛 066044 苣通信作者，E-mail: zhanglifeng@ysu.edu.cn 摘    要    采用数学模拟方法研究钢轨钢连铸坯脱氢退火行为，分析不同退火温度、退火时间条件下连铸坯脱氢效果，优化了 脱氢退火工艺. 在脱氢退火过程中，连铸坯角部和边部的氢含量快速降低，而连铸坯中心氢含量在加热段后期开始降低；随 着退火温度的升高，连铸坯中心脱氢的起始点明显提前，最大脱氢速率显著增加. 随着均热段时间逐渐延长，连铸坯中心氢 含量明显降低，但脱氢速率的增加幅度逐渐减小. 通过优化脱氢退火工艺参数，连铸坯中心氢的质量分数能够降低至 0.6×10−6，脱氢效果显著. 关键词    大方坯；脱氢；退火温度；退火时间；数值模拟 分类号    TF777.2 Numerical simulation of dehydrogenation annealing in bloom JIANG Dong-bin1) ，ZHI Jian-guo2) ，SONG Hai2) ，GAO Yong2) ，ZHANG Li-feng3) 苣 1) School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China 2) Baotou Iron and Steel Co. Ltd., Baotou 014000, China 3) State Key Lab of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066044, China 苣 Corresponding author, E-mail: zhanglifeng@ysu.edu.cn ABSTRACT    Due to moisture in the ore, auxiliary material, and ladle refractory material, the hydrogen element is easily enriched in molten steel. In the metallurgy process, some hydrogen atoms form bubbles and are removed by gravity, whearas others solidify in the strand  and  remain  in  the  produced  steel.  When  the  hydrogen  content  reaches  a  certain  critical  value,  the  enriched  hydrogen  atoms congregate to produce a white spot, which greatly reduces the strength and toughness of the steel product, and leads to brittle fracture during its service period. At present, the RH (Ruhrstahl–Heraeus) and VD (vacuum degasser) refining processes are commonly applied in steel plants, which can reduce the hydrogen content to less than 2×10−6. With the demand for high quality steel, the hydrogen content must be further decreased, so hydrogen diffusion in solid steel during the annealing process is gradually attracting increasing attention. In this study, a two-dimensional model was built to investigate the characteristic of dehydrogenation in the bloom annealing process of rail steel.  Moreover,  the  effect  of  annealing  temperature  and  annealing  time  on  hydrogen  diffusion  were  analyzed,  and  the  annealing parameters were optimized. During the dehydrogenation annealing process, the hydrogen content at the corners and edges of the bloom are  found  to  decrease  rapidly,  while  that  in  the  center  of  the  strand  begin  to  decrease  in  the  later  heating  stage.  As  the  annealing temperature increases, the starting point of dehydrogenation in the bloom center moves ahead and the maximum dehydrogenation rate increases significantly. With the extension of the soaking period, the central hydrogen content of bloom decreases significantly, but the increase rate of the dehydrogenation gradually decreases. By optimizing the bloom annealing parameters, the hydrogen content in the 收稿日期: 2020−03−16 基金项目: 国家自然科学基金资助项目（U186026，51725402，51904024）；中央高校基本科研业务费资助项目（FRF-TP-18-098A1）；中国国家 重点研发计划专项资助项目（2017YFB0304001）；博士后科学基金面上资助项目（2018M641194） 工程科学学报，第 42 卷，第 7 期：862−868，2020 年 7 月 Chinese Journal of Engineering, Vol. 42, No. 7: 862−868, July 2020 https://doi.org/10.13374/j.issn2095-9389.2020.03.16.003; http://cje.ustb.edu.cn