高速连铸结晶器内凝固传热行为及其均匀性控制  

Heat transfer behavior and homogenous solidification control for high-speed continuous casting slab mold

作　　者：朱苗勇 蔡兆镇 ZHU Miao-yong;CAI Zhao-zhen(School of Metallurgy,Northeastern University,Shenyang 110819,China)

机构地区：[1]东北大学冶金学院,沈阳110819

出　　处：《工程科学学报》2022年第4期703-711,共9页Chinese Journal of Engineering

基　　金：国家自然科学基金资助项目(52174307);兴辽英才计划资助项目(XLYC1802032)。

摘　　要：从分析高拉速包晶钢板坯连铸结晶器内凝固传热行为特征入手,首先阐明拉速对结晶器内的界面热阻、凝固坯壳的温度与应力分布的影响规律,研究发现拉速超过1.6 m·min^(−1)时,界面热阻明显增加,拉速由1.4 m·min^(−1)提升至1.6 m·min^(−1)和1.8m·min^(−1)时,出结晶器坯壳厚度相应减少约10%,其发生漏钢的危险不断增加;在此基础上,阐述了结晶器的内腔结构、保护渣、振动与液面控制等控制结晶器内坯壳凝固均匀性的相关技术.要实现高速连铸,首要应考虑结晶器内腔结构的优化设计,使其能更好地迎合凝固坯壳的生长,研制适合包晶钢等凝固特点的专用连铸保护渣至关重要,铸坯鼓肚控制也是保障高拉速液面稳定的关键.High-speed continuous casting is the theme for developing a new generation of high-efficiency continuous casting technology as well as a high-efficiency and green steelmaking production line.Presently,the actual casting speed for slabs in China is no more than 1.8 m·min^(−1),and it is in the range of 1.2-1.4 m·min^(−1) for continuous casting of peritectic steel.With the increase in the casting speed,the negative factors affecting the solidification in continuous casting mold become more evident,and the lubrication between mold copper plate and solidifying shell deteriorates.The friction force increases due to the increase of heat flux and decrease of mold flux consumption.Hence,the thickness of solidifying shell reduces and becomes nonuniform,decreasing its ability to resist all types of stress and strain during casting.Thus,the occurrence of breakout and cracks with high frequency greatly influences production.The technical issue of high-speed casting and the key to making it a reality should be resolved to ensure homogeneous growth.In this paper,the behavior of heat transfer and solidification in slab mold with high-speed casting for peritectic steel was analyzed.The effect of casting speed on the interfacial heat transfer resistance and the distribution of temperature and stress for solidifying shells in mold were investigated.It was found that the interfacial heat resistance increased evidently as the casting speed was greater than 1.6 m·min^(−1).The thickness of solidified shell at the exit of the mold was reduced by approximately 10%,as the casting speed increased from 1.4 m·min^(−1) to 1.6 m·min^(−1) and 1.8 m·min^(−1),making it more dangerous for breakout.The relative technologies such as the shape,flux,oscillation,and surface fluctuation for mold with homogenous solidification were presented and discussed.The optimization of mold inner cavity fitting for the growth of solidifying shell should be considered first for the uniformity control of peritectic steel solidification in a high-spe

关 键 词：高速连铸 均匀凝固 包晶钢 高效传热结晶器 保护渣 结晶器液面控制 

分 类 号：TF777[冶金工程—钢铁冶金]