论文部分内容阅读
良好的表面质量对于直接进行冷轧的双辊连铸不锈钢薄带是很重要的。因而,AISI304不锈钢的表面质量是双辊薄带连铸工艺投入商业化生产的一个主要问题。在双辊连铸薄带中常出现的表面缺陷包括纵向和横向裂纹或皱纹以及不平整,它们主要是由两个辊子之间弯液面的气体卷入和表面波动引起的。 在这项研究中我们采用了一个模型化软件来模拟倾斜双辊连铸中半稳态熔池的流动行为并调查研究生产出的薄带流动特性和表面质量的关系。根据计算出的流动模型得出流动特性,并将它和与计算相同铸造条件下由实验用铸机生产出的薄带的表面质量相联系。通过这种过程,我们得出几个关系。首先,熔池液位较低时薄带上出现表面皱纹。这个问题通过提高液位以降低流动强烈程度减少液面的波动来得到改善。其次,由于在辊子/钢水/空气三相的交叉点附近产生巨大涡流而导致的再循环是熔渣/炉渣夹杂的主要原因。另外,由于采用较高的辊子角度以及靠近低的辊子的倾斜进料位置,在弯液面表面得到更稳定的流动。
Good surface quality is important for direct cold rolling of twin roll cast stainless steel ribbons. Thus, the surface quality of AISI 304 stainless steel is a major issue for the commercial production of twin-roll strip casting processes. Surface defects that often occur in twin-roll continuous casting ribbons include longitudinal and transverse cracks or wrinkles and irregularities that are mainly caused by gas entrainment and surface fluctuations at the meniscus between the two rolls. In this study, we used a modeling software to simulate the flow behavior of a semi-steady pool in inclined twin-roll casting and investigated the relationship between the flow characteristics of the strip produced and the surface quality. The flow behavior was derived from the calculated flow model and linked to the surface quality of the strip produced from the experimental caster under the same casting conditions. Through this process, we come to a few relationships. First, surface wrinkles appear on the ribbon when the pool level is low. This problem is improved by raising the level to reduce the intensity of the flow and reduce the fluctuation of the liquid level. Second, recirculation due to the huge eddy currents near the intersection of the roller / molten steel / air phase is the main cause of slag / slag inclusions. In addition, a more steady flow at the meniscus surface is achieved due to the higher roll angle and the inclined feed position near the lower roll.