连铸坯振痕和凝固钩基础研究

Basic research on oscillation marks and solidification hooks of continuous casting slabs

对低碳钢连铸板坯窄面进行了振痕及凝固钩的研究,根据凝固钩的形貌定义了凝固钩深度、长度、角度等参数,观察到了完整叶状的凝固钩典型形貌,发现了凝固钩捕获气泡的现象,并统计了凝固钩的出现与振痕深度的关系。经过对结果的分析,得到了如下结论:完整叶状凝固钩结构是由形核线和两侧的枝晶组成的;凝固钩能捕获结晶器内上浮的气泡而影响铸坯的表面质量;在大于0.5 mm的深振痕处不存在凝固钩结构。最后,用观察结果解释了振痕变深时凝固钩的变化过程。

The oscillation marks and subsurface hooks from the narrow face of a low-carbon Al-killed continuous casting slab were studied. According to the hook morphology,the hook characteristics including hook depth,hook length and hook angle were defined. The typical whole-leaf hook was observed,the capture of bubbles by hooks was found,and the relation between oscillation mark depth and occurred hooks was analyzed. It is concluded that the whole- leaf hook is made up of the hook line and the dendrites on both side of the line,and the capture of bubbles by hooks could deteriorate the slab surface quality. Besides,hooks hardly exist near excessive deep oscillation marks whose depth was over 0.5 mm. The variation of hooks with the depth of oscillation marks is discussed.