Chen Liang, Chen Xiqing, Wang Pu, Zhang Jiaquan
School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, No. 30 Xueyuan Road, Haidian District, Beijing 100083, China.
Materials (Basel). 2024 Oct 5;17(19):4888. doi: 10.3390/ma17194888.
Based on a physical water model with a scaling factor of 0.5 and a coupled flow-heat transfer-solidification numerical model, this study investigates the influence of the submerged entry nozzle (SEN) depth on the mold surface behavior, slag entrapment, internal flow field, temperature distribution, and initial solidification behavior in slab casting. The results indicate that when the SEN depth is too shallow (80 mm), the slag layer on the narrow face is thin, leading to slag entrapment. Within a certain range of SEN depths (less than 170 mm), increasing the SEN depth reduces the impact on the mold walls, shortening the "plateau period" of stagnated growth on the narrow face shell. This allows the upper recirculation flow to develop more fully, resulting in an increase in the surface flow velocity and an expansion in the high-temperature region near the meniscus, which promotes uniform slag melting but also heightens the risk of slag entrainment due to shear stress at the liquid surface (with 110 mm being the most stable condition). As the SEN depth continues to increase, the surface flow velocity gradually decreases, and the maximum fluctuation in the liquid surface diminishes, while the full development of the upper recirculation zone leads to a higher and more uniform meniscus temperature. This suggests that in practical production, it is advisable to avoid this critical SEN depth. Instead, the immersion depth should be controlled at a slightly shallower position (around 110 mm) or a deeper position (around 190 mm).
基于比例因子为0.5的物理水模型以及耦合的流-热传递-凝固数值模型，本研究调查了浸入式水口（SEN）深度对板坯连铸结晶器表面行为、卷渣、内部流场、温度分布及初始凝固行为的影响。结果表明，当SEN深度过浅（80mm）时，窄面的渣层较薄，导致卷渣。在一定的SEN深度范围内（小于170mm），增加SEN深度可减小对结晶器壁的冲击，缩短窄面铸坯壳停滞生长的“平稳期”。这使得上部回流更加充分地发展，导致表面流速增加以及弯月面附近高温区域扩大，这促进了熔渣的均匀熔化，但也因液面处的剪切应力增加了卷渣风险（110mm时为最稳定状态）。随着SEN深度继续增加，表面流速逐渐降低，液面的最大波动减小，而上部回流区的充分发展导致弯月面温度更高且更均匀。这表明在实际生产中，应避免该临界SEN深度。相反，浸入深度应控制在稍浅位置（约110mm）或较深位置（约190mm）。
