连铸板坯轧制过程缩孔闭合行为的数值模拟

Numerical simulation of shrinkage and sealing behavior during rolling of continuously cast slab

在连铸板坯的生产过程中,铸坯内部常会出现大量的缩孔,球形缩孔最为典型,缩孔导致内部缺陷,严重降低了铸坯的质量。研究运用三维有限元模型来模拟板坯轧制过程中的缩孔闭合行为,并用试验验证了模型模拟的准确性。结果表明,三维有限元模拟结果与试验结果吻合良好,模型可以正确预测了热轧过程缩孔的闭合行为。在轧制过程中,不同直径的球型缩孔的演化特征几乎相同,直径大的球形缩孔闭合过程相对较快;同一直径的缩孔距离轧件厚度中心线越远即距离铸坯表面越近,越容易闭合,缩孔闭合过程中在轧件中的相对位置没有变化。

In the production process of continuous casting slabs, there are often a large number of shrinkage holes inside the casting blanks. The spherical shrinkage pores are the most typical, shrinkage holes lead to internal defects, and the quality of the slabs is severely reduced. Therefore, the three-dimensional finite element model used in this paper was used to simulate the behavior of the shrinkage cavity during slab rolling, and the accuracy of the model simulation was verified by experiments. The results show that the three-dimensional finite element simulation results agree well with the experimental results, and the model can correctly predict the closing behavior of shrinkage pores during hot rolling. During the rolling process, the evolution characteristics of the spherical craters of different diameters are almost the same, and the closing process of the spherical craters with a large diameter is relatively fast; the farther the craters of the same diameter are away from the centerline of the thickness of the rolling stock, the less distance from the surface of the cast slab. Nearly. the easier it is to close, the relative position in the rolling stock during closing of the shrinkage hole does not change.