摘要
高拉速薄板坯连铸连轧生产线在轧制薄规格、开发高附加值产品上具有得天独厚的优势,但拉速过高会使薄板坯热轧卷产生表面裂纹等问题,严重影响质量的提升,反过来又限制了拉速的进一步提高。本文探讨了唐钢薄板坯高速连铸提速过程中,SS400热板卷表面裂纹多、质量差的原因,并从钢水成分、结晶器漏斗形状、保护渣性能方面提出了工艺控制措施。通过控制钢水中w(C)≥0.19%,远离包晶反应;控制w(S)≤0.005%,降低裂纹敏感性;采用上口弧形、下口平直的短漏斗型结晶器,在结晶器内形成均匀的初生坯壳;选用高碱度(R>1.6)保护渣,增加保护渣热阻降低热流密度,保证结晶器“缓冷”,在无结晶器电磁制动前提下SS400热板卷高拉速裂纹指数大幅降低,裂纹指数较常规拉速降低了87%,因裂纹导致的月废次降由232 t下降到67 t,板卷质量得到了显著改善。
The high drawing speed thin slab continuous casting and rolling production line has unique advantages in rolling thin specifications and developing high value-added products,but too high drawing speed will cause surface cracks and other problems in thin slab hot-rolled coils,which seriously affects the improvement of quality,which in turn limits the further improvement of drawing speed.In this paper,the reasons for the many cracks and poor quality of SS400 hot plate coils are discussed in the process of high-speed continuous casting of thin slabs of Tangsteel,and the process control measures are proposed from the aspects of molten steel composition,mold funnel shape and slag protection performance.By controlling the w(C)≥0.19%in the molten steel,away from the cladding reaction,controlling the w(S)≤0.005%,reducing the crack sensitivity,using a short funnel mold with arc shape at the upper mouth and straight at the lower mouth,forming a uniform primary billet shell in the mold,and using high alkalinity(R>1.6)to protect the slag,increasing the thermal resistance of the protective slag and reducing the heat flux density,and ensuring the"slow cooling"of the mold Under the premise of no mold electromagnetic braking,the crack index of SS400 hot coil with high drawing speed is greatly reduced,the crack index is reduced by 87%compared with the conventional drawing speed,and the monthly waste reduction caused by cracks is reduced from 232 t to 67 t,and the quality of the coil has been significantly improved.
作者
李超
赵建平
单庆林
路博勋
蒋昭阳
邢天庆
Li Chao;Zhao Jianping;Shan Qinglin;Lu Boxun;Jiang Zhaoyang;Xing Tianqing(HBIS Group Tangsteel Company,Tangshan 063016,Hebei)
出处
《河北冶金》
2023年第12期75-79,共5页
Hebei Metallurgy
关键词
高拉速
薄板坯连铸
SS400
裂纹指数
结晶器
碱度
保护渣
high drawing speed
thin slab continuous casting
SS400
crack index
mold
alkalinity
protective slag
作者简介
李超(1989-),男,硕士,工程师,2014年毕业于东北大学冶金工程专业,现在河钢集团唐钢公司长材事业部主要从事连铸质量技术研究,E-mail:449133180@qq.com。
