结晶器电磁搅拌对475 mm特厚板坯表层大颗粒夹杂物控制研究
Research on the control of large particle inclusions on 475 mm extra-thick slab surface by mold electromagnetic stirring
闫晟昌 1甄新刚 2张炯明 1尹延斌 1雷星1
作者信息
- 1. 北京科技大学绿色低碳钢铁冶金全国重点实验室,北京 100083
- 2. 北京科技大学绿色低碳钢铁冶金全国重点实验室,北京 100083;日钢营口中板有限公司,营口 115005
- 折叠
摘要
特厚板坯已成为基础建设所依赖的重要钢铁材料,广泛应用于军用和民用领域.铸坯表层大颗粒夹杂物是影响铸坯质量的关键因素之一.在475 mm特厚板坯连铸生产过程中,为探究结晶器电磁搅拌(M-EMS)对铸坯表层夹杂物的影响,进行有M-EMS和无M-EMS的对比试验.采用无水电解法提取试样中的大颗粒夹杂物,计算其数量密度和质量密度.结果表明,与无M-EMS时相比,有M-EMS时铸坯表层各尺寸夹杂物质量密度和数量密度均明显减小,其中,尺寸大于150 μm的大颗粒夹杂物减少幅度最大,质量密度由3.817 mg/kg减小至1.511 mg/kg,表明M-EMS能有效控制特厚板坯表层大颗粒夹杂物.对夹杂物进行成分分析,结果表明,夹杂物的来源可能是生产过程中产生的脱氧产物(Al2O3-SiO2或单一的Al2O3)、浇注过程中卷入的保护渣(含有Na2O)以及由于钢水冲刷落入钢液中的耐火材料.
Abstract
Extra-thick slab has become an important iron and steel material for infrastructure construction and is widely used in military and civilian applications.The large particle inclusion on the surface of a billet is one of the key factors affecting the quality of the billet.To investigate the influence of mould electromagnetic stirring(M-EMS)on the surface inclusions of 475 mm extra-thick slab continuous casting,a comparative test with and without EMS was conducted.The large particle inclusions in the samples were extracted by an hydrous large-scale electrolysis method,and the quantity density and mass density were calculated.The results show that the inclusions of each size on the surface of the billet with EMS can be reduced obviously compared with that without M-EMS,among which the largest-particle inclusions with the size greater than 150 μm have the largest reduction,and the mass density is reduced from 3.817 mg/kg to 1.511 mg/kg.The results also indicate that the use of mould electromagnetic stirring can effectively reduce the large particle inclusions on the surface of extra-thick slab;at the same time,the inclusions are found to be deoxidized products produced in the production process(Al2O3-SiO2 or pure Al2O3),protective slag involved in the casting process(contains Na2O)and refractories that fall into the liquid steel as the molten steel washes away.The components are silicates such as CaO-MgO-Al2O3-SiO2 and calcium aluminate.
关键词
特厚板坯/结晶器电磁搅拌/无水大样电解/夹杂物Key words
extra-thick slab/electromagnetic stirring of mold/anhydrous large-scale electrolysis/inclusion引用本文复制引用
出版年
2024
NETL
NSTL
万方数据