摘要：结晶器是钢铁冶金行业至关重要的一个装置，连铸结晶器内钢液的流体流动状况对钢水中存在的非金属夹杂物的去除、保护渣卷入钢液、凝固坯壳层的形成等有着至关重要的影响。钢液中出现的不合理的流体流动状况可能会造成结晶器内钢液在结晶器铜壁处壁面上的流速过大，弯月面出现较大的波动，对铸坯窄面冲击强度过大等现象，最终导致“卷渣”或“拉漏”等。这将最终影响到连铸工艺的顺利进行和铸坯质量。为保证高效的连铸效率的和优良的铸坯质量，我们需要了解结晶器内钢液的流体流动情况。

    本研究以宝武集团特钢公司板坯连铸结晶器为原型，基于有限元软件ANSYS中的CFX模块，对连铸结晶器钢液内钢液的流体流动行为进行数学模拟分析。根据建立的三维模型，重点研究计算不同拉速对钢液流体流动行为的影响，并对现有工艺提出优化指导。

 研究结果表明：分别取拉速为0.6m/min，0.55m/min，0.5m/min，0.45m/min及0.4m/min时作模拟实验。观察钢液面速率的变化可知：（1）钢液从水口注入结晶器内分为射流区，上回旋区和下回旋区。（2）现有工艺条件下，拉速为0.6m/min时，钢液面速度为0.24m/s，会发生卷渣现象；（3）拉速为0.45m/min~0.55m/min时，钢液面的速度为0.15m/s~0.18m/s，可能会发生卷渣，拉速为0.4m/min时钢液面的速度为0.14m/s，不会发生卷渣。

关键词：连铸结晶器，流场，数学模拟，水口，铸坯拉速

Analysis of Flow Field of Molten Steel in Continuous Casting Mold Under Low Speed

Abstract：Crystallizer is a very important device in the iron and steel metallurgy industry. The fluid activity of the molten steel in the continuous casting mold has a crucial influence on the removal of the mixture in molten steel, the entrainment of mold powder, and the formation of a condensed layer in the shell. . The unreasonable fluid activity of the molten steel may cause the flow velocity of the molten steel recrystallizer in the crystallizer to be too large, the fluctuation of the meniscus is aggravated, and the phenomenon that the impact strength of the narrow surface of the cast strand is too large and further causes “roll slag” or “pulling” Leakage and so on. This will ultimately affect the smooth progress of the continuous casting process and the quality of the slab. In order to ensure efficient continuous casting efficiency and excellent slab quality, we need to understand the fluid activity of molten steel in the mold.

In this study, Baowu Group Special Steel Co., Ltd. slab continuous casting mold was used as the prototype. Based on the finite element software ANSYS CFX module, the fluid flow behavior of the liquid steel in the continuous casting mold liquid steel was mathematically simulated. According to the established three-dimensional model, the influences of different  pulling speed on the fluid behavior of liquid steel are mainly studied, and optimization guidance for the existing process is provided.

The results show that the simulation experiments were carried out when the casting speeds were 0.6m/min, 0.55m/min, 0.5m/min, 0.45m/min and 0.4m/min, respectively. Observing the change of the liquid surface velocity of the steel, we can see that: (1) The molten steel is injected into the crystallizer from the nozzle and pided into a jet zone, an upper race zone and a lower race zone.(2) Under the existing process conditions, when the pulling speed is 0.6m/min, the liquid surface velocity is 0.24m/s, and the slag slag phenomenon will occur;(3) When the pulling speed is 0.45m/min~0.55m/min, the speed of the molten steel surface is 0.15m/s~0.18m/s, and the slag may be generated. When the pulling speed is 0.4m/min, the molten steel surface The speed is 0.14m/s, no slag formation.

KeyWords：Continuous casting mold, flow field, mathematical simulation, nozzle, casting speed