钢水流动对连铸坯初期凝固的影响  

EFFECT OF MELT FLOW ON INITIAL SOLIDIFIED SHELLOF CONTINUOUS CAST STRAND

作　　者：于功利[1] 井上健 安中弘行 

机构地区：[1]鞍山钢铁(集团)公司

出　　处：《钢铁》1998年第4期13-15,12,共4页Iron and Steel

摘　　要：为了定量把握结晶器中的钢水流动、钢水过热度及结晶器传热阻力对初期凝固坯壳的凝固不均一的影响，利用水冷铜板的浸渍实验，测定了各种铸造条件下的凝固坯壳厚度、凝固不均一度及树枝晶偏角；利用水力模型实验，并对实机铸坯的凝固组织分析，ＥＰＭＡ对负偏析带的线分析，得出了在结晶器中凝固坯壳上负偏析带的产生原因。其主要结果是：①随着钢水流动速度及过热度的增加，凝固坯壳厚度减少，凝固坯壳不均一度增大；②缓冷结晶器可有效地改善低碳钢初期凝固坯壳的不均一性；③在连铸坯表层（６～１０ｍｍ）存在的负偏析带产生于距弯月面２５０～４５０ｍｍ处，其生成原因是由于浸渍水口的吐出流所致。To estimate quantitatively the effect of melt flow in mold and superheat as well as the mold heat transfer resistance,on the unevenness of initial solidified shell,the water cooled copper plate dipping test has been used to measure the thickness of solidified shell and dendrite angle under various casting conditions.The reason of white band formation in the solidified shell in the mold has been studied by means of water modeling test and the analysis of the solidified microstructure of practical CC slab and liner analysis of white band has been performed by EPMA.Main results are as follows:①The thickness of solidified shell decreases and the unevenness is increased with the increase of flow velocity and superheat of the melt;②Slow cooling mold can effectively reduce the unevenness of initially solidified shell of hypoperitectic steel;③The white band existing under the surface of CC slab(6～10 mm)is formed at 250～450 mm from meniscus,and resulted by the jet flow from submerged nozzle.

关 键 词：连续铸造 钢水流动 过热度 凝固不均一度 

分 类 号：TF777[冶金工程—钢铁冶金] TG111.4[金属学及工艺—物理冶金]