摘要：随着高效连铸技术的不断发展和对钢的质量要求的不断提高，结晶器部分功能和作用的强化始终是冶金工作者关注的内容。连铸生产中，结晶器是其中的极其重要的一环，钢水在结晶器中流动时，如果工艺参数控制不当，特别是钢水的流场控制不当，有时会将上方的保护渣卷入到钢水中来，会对所生产的钢材的质量产生较大的不良影响。所以为了可以提高钢材的质量，我们需要对结晶器内的钢水的流动做流场分析，从而了解其内部的流动方式，借由其流动方式的分析，对连铸过程参数进行优化，使得流场变得更加合理，防止保护渣的卷入。本论文以宝钢特钢公司的840L钢种为研究对象，按照宝钢特钢公司的立式连铸结晶器的尺寸进行建模，网格划分然后进行对结晶器内的钢液的流场计算分析。研究结果表明：（1）拉速为0.6m/min时相对于其他拉速来说卷渣的发生概率相对较小，但是仍然不是最优工艺，还是会有卷渣的情况发生。（2）当拉速降低为0.5m/min时将不产生卷渣。

关键词：连铸；结晶器；保护渣的卷入；模型建立；计算

Analysis of Flow Field of Molten Steel in Continuous Casting Mold under High Speed

Abstract: With the continuous development of efficient continuous casting technology and the increasing demand for steel quality in the market, crystallizer steelmaking has also received more and more attention. One of the main purposes of continuous casting production is to purify the steel, and one of the most important components of the mold is that molten steel will contain some inclusions when it flows in the mold and the upper mold powder will also be involved in the molten steel. The quality of the steel produced has a greater impact. Therefore, in order to improve the quality of steel, we need to do a flow field analysis on the flow of molten steel in the crystallizer to determine the internal flow pattern. By optimizing the flow of the mold, the flow field is stabilized and prevented. Entrainment of mold powder and entrainment of some inclusions. This paper takes Baosteel 840L steel as the research object, modeling according to Baosteel's vertical continuous casting mold size, meshing and then calculating and analyzing the flow field of liquid steel in the mold.The results of the study show that: (1) When the pulling speed is 0.6m/min, the probability of occurrence of slag is relatively small relative to other casting speeds, but it is still not the optimal process, or there will be slag entrapment. (2) No slag formation will occur when the casting speed is reduced to 0.5m/min.

Key words: continuous casting; mold; entrainment of mold flux; model establishment; calculation

目  录

1  绪论 1

1.1  文献综述 1

1.1.1  钢的连铸结晶器 1

1.1.2  结晶器内钢液的流动行为 1

1.1.3  结晶器内卷渣 2

1.1.4  结晶器内钢液行为的数值模拟研究现状 3

1.1.5  流体流动模型 4

1.1.6  结晶器内流动行为的模拟方法研究 4

1.1.7  主要工艺 5

1.2  课题研究目的和意义 5

2  连铸结晶器内钢水流动过程的数学模型 8

2.1  数学模型 8

2.1.1  基本假设 8

2.1.2  控制方程 8

2.2  边界条件 9

2.3  物理模型的建立 9

2.4  网格划分 19

2.5  计算 36

3  结果分析 40

3.1  宝钢特钢连铸结晶器内钢水的流动状态 40

3.2  宝钢特钢连铸结晶器内钢水的流动速率分布图与云图 40

3.3  结晶器内钢液-熔渣界面处钢水的流动速度与卷渣 42

3.4  拉速对结晶器内钢水流场的影响 43

3.5  水口插入深度对结晶器内钢水流场的影响 47

5  结论 50

致谢 51

参考文献 52