连铸坯中缩敏感系数研究

摘要

连铸坯内部中心缩松、缩孔是影响铸坯内部质量的主要缺陷之一. 综合运用凝固理论、数值模拟、实验研究、数学推导等手段,提出了描述连铸坯中缩缺陷形成可能性大小的连铸坯中缩敏感系数,并以中缩敏感系数为桥梁,建立了工艺因素与中缩缺陷的关系. 结果表明,二冷水是形成连铸坯中缩缺陷的主要因素;随着过热度的增加,连铸坯愈易形成中心缩孔、缩松缺陷;一冷水量对中缩敏感系数的影响较小. 该判据用于连铸过程控制可得到较高质量连铸坯.%Centerline shrinkage is the main defect that affects the inner quality of continuous casting slab. Sensitivity factor of centerline shrinkage (SFCS), which is the criterion for shrinkage formation in slab, is put forward based on solidification theory, numerical simulation, experimental investigation and mathematical deduction. The relation between centerline shrinkage of slab and technical parameters of continuous casting is discussed according to SFCS. The following results are concluded: secondary cooling water is the main factor of forming centerline shrinkage; with the increase of superheat degree, it is easier to form centerline shrinkage in the slab; and quantity of cooling water in mould has a little effect on SFCS of slab. The criterion could be applied to the continuous casting process to optimize technical parameters in order to obtain slab of good quality.