超高碱度连铸保护渣固渣膜凝固和结晶行为特性  

Crystallization features of solid slag films of ultrahigh-basicity mold fluxes for continuous casting

作　　者：龙潇[1] 何生平[1] 王谦[1] LONG Xiao,HE Sheng-ping,WANG Qian(College of Materials Science and Engineering, Chongqing University, Chongqing 400044, Chin)

机构地区：[1]重庆大学材料科学与工程学院

出　　处：《钢铁研究学报》2018年第1期21-25,共5页Journal of Iron and Steel Research

基　　金：国家自然科学基金重点基金资助项目(U1660204);中国博士后科学基金资助项目(2016M592119);重庆市研究生科研创新资助项目(CYB14035);江西省博士后科研资助项目(2016KY19)

摘　　要：针对工业应用的超高碱度保护渣（二元碱度为1.74）,采用改进后的水冷铜探头浸入液渣,设置不同的探头浸入时间获取不同凝固阶段的渣膜。分析了固渣膜的生长速度、渣膜总体孔隙率、渣膜凝固结晶和渣膜内的脱玻璃化过程。结果表明,渣膜凝固初期（0～15 s）玻璃层平均生长速度较快,为79.9μm/s。固渣膜脱玻璃化析出主要矿相为细小球状钠氟石（2CaO·SiO2·NaF）,固渣膜玻璃层脱玻璃化平均速度可达65μm/s。靠近液渣的外层渣膜矿相为板条状枪晶石（3CaO·2SiO2·CaF2）,该板条状枪晶石的凝固生长速度较慢,但使固渣膜的整体孔隙率在凝固后期维持在较高水平,相对降低了固渣膜的有效导热系数。The ultrahigh-basicity mold flux for industrial application（ binary basicity of 1. 74） was selected and solidified by an improved water-cooled copper probe. Different probe immersion times were adopted to analyze the solidification process of films. The growth speeds and closed porosities of solid films were measured. The crystallization processes by solidification and devitrification were also analyzed,respectively. The results indicate that the growth speed of the solid slag film during the initial solidification period（ 0-15 s） is 79. 9 μm/s. 2 CaO·SiO2·Na F with small spherical shapes is the primary crystal which leads to devitrification. The average devitrification speed of the glassy film is 65 μm/s,and the primary crystal in the outer layer of solid films is lathlike cuspidine（ 3CaO·2 SiO2·CaF2）. The growth of the lathlike cuspidine in the outer layer of films increases the closed porosity and decreases the effective thermal conductivity of solid slag films.

关 键 词：保护渣 超高碱度 脱玻璃化 结晶 孔隙率 矿相 

分 类 号：TF777[冶金工程—钢铁冶金]