特厚板坯窄面侧裂缺陷形成原因及控制  

Formation Reason and Control of Lateral Cracking in Narrow Face of Ultra-thick Slab

作　　者：甄新刚[1] 朱志远[2] 王玉龙[2] 王国连[1] 赵晶[2] 蒯多圣 Zhen Xingang;Zhu Zhiyuan;Wang Yulong;Wang Guolian;Zhao Jing;Kuai Duosheng(Shougang Jingtang United Iron & Steel Co., Ltd., Tangshan Hebei 063200,China;Qinhuangdao Shouqin Metal Material Co., Ltd.,Qinhuangdao Hebei 066326, China)

机构地区：[1]首钢京唐钢铁联合有限责任公司,河北唐山063200 [2]秦皇岛首秦金属材料有限公司,河北秦皇岛066326

出　　处：《上海金属》2018年第1期15-18,27,共5页Shanghai Metals

摘　　要：窄面侧裂是特厚板坯常发的表面缺陷之一。通过试验研究和生产数据分析,发现特厚板坯窄面侧裂缺陷的形成原因为:包晶反应使得结晶器内的初生坯壳不均匀生长、结晶器保护渣的物理属性和水口浸入深度的变化方式对结晶器热流的影响,是侧裂在结晶器内起源的主要原因;在较大的足辊冷却强度和足辊挤压力下,起源于结晶器的微裂纹在足辊区被扩展,形成了窄面侧裂缺陷。通过优化保护渣属性、结晶器窄面锥度和水口浸入深度变化方式等措施,使得铸坯窄面侧裂发生率由10.2%降低至2.8%。Lateral cracking on narrow face of slab is the one of surface defects frequently occurred in ultra-thick slab.Through experimental research and production data analysis,the formation reason of lateral cracking of ultra-thick slab was found:The uneven growth of initial shell in mold for peritectic reaction,the effect of the physical property of mold slag and the change style of immersion depth on the mold flux were the main reasons of the origin of lateral cracking.Thus the tiny cracking will be extended in the foot roller area by the action of high cooling intensity and press strength of foot rollers,which will broaden lateral defects on narrow face.A series of measures of optimizing mold slag property,taper of mold narrow face and style change of immersion depth of nozzle were adopted.The percentage of incidence of lateral cracking decreased from10.2%to2.8%.

关 键 词：特厚板坯 窄面侧裂 保护渣 浸入深度 锥度 

分 类 号：TF777[冶金工程—钢铁冶金]